New and improved IK system for Skeleton2D

This PR and commit adds a new IK system for 2D with the Skeleton2D node
that adds several new IK solvers, a way to control bones in a Skeleton2D
node similar to that in Skeleton3D. It also adds additional changes
and functionality.

This work was sponsored by GSoC 2020 and TwistedTwigleg.

Full list of changes:
* Adds a SkeletonModifier2D resource
  * This resource is the base where all IK code is written and executed
  * Has a function for clamping angles, since it is so commonly used
  * Modifiers are unique when duplicated so it works with instancing
* Adds a SkeletonModifierStack2D resource
  * This resource manages a series of SkeletonModification2Ds
  * This is what the Skeleton2D directly interfaces with to make IK possible
* Adds SkeletonModifier2D resources for LookAt, CCDIK, FABRIK, Jiggle, and TwoBoneIK
  * Each modification is in its own file
  * There is also a SkeletonModifier2D resource that acts as a stack for using multiple stacks together
* Adds a PhysicalBone2D node
  * Works similar to the PhysicalBone3D node, but uses a RigidBody2D node
* Changes to Skeleton2D listed below:
  * Skeleton2D now holds a single SkeletonModificationStack2D for IK
  * Skeleton2D now has a local_pose_override, which overrides the Bone2D position similar to how the overrides work in Skeleton3D
* Changes to Bone2D listed below:
  * The default_length property has been changed to length. Length is the length of the bone to its child bone node
  * New bone_angle property, which is the angle the bone has to its first child bone node
  * Bone2D caches its transform when not modified by IK for IK interpolation purposes
  * Bone2D draws its own editor gizmo, though this is stated to change in the future
* Changes to CanvasItemEditor listed below:
  * Bone2D gizmo drawing code removed
  * The 2D IK code is removed. Now Bone2D is the only bone system for 2D
* Transform2D now has a looking_at function for rotating to face a position
* Two new node notifications: NOTIFICATION_EDITOR_PRE_SAVE and NOTIFICATION_EDITOR_POST_SAVE
  * These notifications only are called in the editor right before and after saving a scene
  * Needed for not saving the IK position when executing IK in the editor
* Documentation for all the changes listed above.

25 files changed, 5281 insertions, 10 deletions

diff --git a/scene/2d/physical_bone_2d.cpp b/scene/2d/physical_bone_2d.cpp
new file mode 100644
index 0000000000..0c1be16174
--- /dev/null
+++ b/scene/2d/physical_bone_2d.cpp
@@ -0,0 +1,303 @@
+/*************************************************************************/
+/*  physical_bone_2d.cpp                                                 */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "physical_bone_2d.h"
+
+void PhysicalBone2D::_notification(int p_what) {
+	if (p_what == NOTIFICATION_INTERNAL_PHYSICS_PROCESS) {
+		// Position the RigidBody in the correct position
+		if (follow_bone_when_simulating) {
+			_position_at_bone2d();
+		}
+
+		// Keep the child joint in the correct position.
+		if (child_joint && auto_configure_joint) {
+			child_joint->set_global_position(get_global_position());
+		}
+	} else if (p_what == NOTIFICATION_READY) {
+		_find_skeleton_parent();
+		_find_joint_child();
+
+		// Configure joint
+		if (child_joint && auto_configure_joint) {
+			_auto_configure_joint();
+		}
+
+		// Simulate physics if set
+		if (simulate_physics) {
+			_start_physics_simulation();
+		} else {
+			_stop_physics_simulation();
+		}
+
+		set_physics_process_internal(true);
+	}
+}
+
+void PhysicalBone2D::_position_at_bone2d() {
+	// Reset to Bone2D position
+	if (parent_skeleton) {
+		Bone2D *bone_to_use = parent_skeleton->get_bone(bone2d_index);
+		ERR_FAIL_COND_MSG(bone_to_use == nullptr, "It's not possible to position the bone with ID: " + itos(bone2d_index));
+		set_global_transform(bone_to_use->get_global_transform());
+	}
+}
+
+void PhysicalBone2D::_find_skeleton_parent() {
+	Node *current_parent = get_parent();
+
+	while (current_parent != nullptr) {
+		Skeleton2D *potential_skeleton = Object::cast_to<Skeleton2D>(current_parent);
+		if (potential_skeleton) {
+			parent_skeleton = potential_skeleton;
+			break;
+		} else {
+			PhysicalBone2D *potential_parent_bone = Object::cast_to<PhysicalBone2D>(current_parent);
+			if (potential_parent_bone) {
+				current_parent = potential_parent_bone->get_parent();
+			} else {
+				current_parent = nullptr;
+			}
+		}
+	}
+}
+
+void PhysicalBone2D::_find_joint_child() {
+	for (int i = 0; i < get_child_count(); i++) {
+		Node *child_node = get_child(i);
+		Joint2D *potential_joint = Object::cast_to<Joint2D>(child_node);
+		if (potential_joint) {
+			child_joint = potential_joint;
+			break;
+		}
+	}
+}
+
+TypedArray<String> PhysicalBone2D::get_configuration_warnings() const {
+	TypedArray<String> warnings = Node::get_configuration_warnings();
+
+	if (!parent_skeleton) {
+		warnings.push_back(TTR("A PhysicalBone2D only works with a Skeleton2D or another PhysicalBone2D as a parent node!"));
+	}
+	if (parent_skeleton && bone2d_index <= -1) {
+		warnings.push_back(TTR("A PhysicalBone2D needs to be assigned to a Bone2D node in order to function! Please set a Bone2D node in the inspector."));
+	}
+	if (!child_joint) {
+		PhysicalBone2D *parent_bone = Object::cast_to<PhysicalBone2D>(get_parent());
+		if (parent_bone) {
+			warnings.push_back(TTR("A PhysicalBone2D node should have a Joint2D-based child node to keep bones connected! Please add a Joint2D-based node as a child to this node!"));
+		}
+	}
+
+	return warnings;
+}
+
+void PhysicalBone2D::_auto_configure_joint() {
+	if (!auto_configure_joint) {
+		return;
+	}
+
+	if (child_joint) {
+		// Node A = parent | Node B = this node
+		Node *parent_node = get_parent();
+		PhysicalBone2D *potential_parent_bone = Object::cast_to<PhysicalBone2D>(parent_node);
+
+		if (potential_parent_bone) {
+			child_joint->set_node_a(child_joint->get_path_to(potential_parent_bone));
+			child_joint->set_node_b(child_joint->get_path_to(this));
+		} else {
+			WARN_PRINT("Cannot setup joint without a parent PhysicalBone2D node.");
+		}
+
+		// Place the child joint at this node's position.
+		child_joint->set_global_position(get_global_position());
+	}
+}
+
+void PhysicalBone2D::_start_physics_simulation() {
+	if (_internal_simulate_physics) {
+		return;
+	}
+
+	// Reset to Bone2D position
+	_position_at_bone2d();
+
+	// Apply the layers and masks
+	PhysicsServer2D::get_singleton()->body_set_collision_layer(get_rid(), get_collision_layer());
+	PhysicsServer2D::get_singleton()->body_set_collision_mask(get_rid(), get_collision_mask());
+
+	// Apply the correct mode
+	RigidBody2D::Mode rigid_mode = get_mode();
+	if (rigid_mode == RigidBody2D::MODE_STATIC) {
+		PhysicsServer2D::get_singleton()->body_set_mode(get_rid(), PhysicsServer2D::BodyMode::BODY_MODE_STATIC);
+	} else if (rigid_mode == RigidBody2D::MODE_DYNAMIC) {
+		PhysicsServer2D::get_singleton()->body_set_mode(get_rid(), PhysicsServer2D::BodyMode::BODY_MODE_DYNAMIC);
+	} else if (rigid_mode == RigidBody2D::MODE_KINEMATIC) {
+		PhysicsServer2D::get_singleton()->body_set_mode(get_rid(), PhysicsServer2D::BodyMode::BODY_MODE_KINEMATIC);
+	} else if (rigid_mode == RigidBody2D::MODE_DYNAMIC_LOCKED) {
+		PhysicsServer2D::get_singleton()->body_set_mode(get_rid(), PhysicsServer2D::BodyMode::BODY_MODE_DYNAMIC_LOCKED);
+	} else {
+		// Default to Rigid
+		PhysicsServer2D::get_singleton()->body_set_mode(get_rid(), PhysicsServer2D::BodyMode::BODY_MODE_DYNAMIC);
+	}
+
+	_internal_simulate_physics = true;
+	set_physics_process_internal(true);
+}
+
+void PhysicalBone2D::_stop_physics_simulation() {
+	if (_internal_simulate_physics) {
+		_internal_simulate_physics = false;
+
+		// Reset to Bone2D position
+		_position_at_bone2d();
+
+		set_physics_process_internal(false);
+		PhysicsServer2D::get_singleton()->body_set_collision_layer(get_rid(), 0);
+		PhysicsServer2D::get_singleton()->body_set_collision_mask(get_rid(), 0);
+		PhysicsServer2D::get_singleton()->body_set_mode(get_rid(), PhysicsServer2D::BodyMode::BODY_MODE_STATIC);
+	}
+}
+
+Joint2D *PhysicalBone2D::get_joint() const {
+	return child_joint;
+}
+
+bool PhysicalBone2D::get_auto_configure_joint() const {
+	return auto_configure_joint;
+}
+
+void PhysicalBone2D::set_auto_configure_joint(bool p_auto_configure) {
+	auto_configure_joint = p_auto_configure;
+	_auto_configure_joint();
+}
+
+void PhysicalBone2D::set_simulate_physics(bool p_simulate) {
+	if (p_simulate == simulate_physics) {
+		return;
+	}
+	simulate_physics = p_simulate;
+
+	if (simulate_physics) {
+		_start_physics_simulation();
+	} else {
+		_stop_physics_simulation();
+	}
+}
+
+bool PhysicalBone2D::get_simulate_physics() const {
+	return simulate_physics;
+}
+
+bool PhysicalBone2D::is_simulating_physics() const {
+	return _internal_simulate_physics;
+}
+
+void PhysicalBone2D::set_bone2d_nodepath(const NodePath &p_nodepath) {
+	bone2d_nodepath = p_nodepath;
+	notify_property_list_changed();
+}
+
+NodePath PhysicalBone2D::get_bone2d_nodepath() const {
+	return bone2d_nodepath;
+}
+
+void PhysicalBone2D::set_bone2d_index(int p_bone_idx) {
+	ERR_FAIL_COND_MSG(p_bone_idx < 0, "Bone index is out of range: The index is too low!");
+
+	if (!is_inside_tree()) {
+		bone2d_index = p_bone_idx;
+		return;
+	}
+
+	if (parent_skeleton) {
+		ERR_FAIL_INDEX_MSG(p_bone_idx, parent_skeleton->get_bone_count(), "Passed-in Bone index is out of range!");
+		bone2d_index = p_bone_idx;
+
+		bone2d_nodepath = get_path_to(parent_skeleton->get_bone(bone2d_index));
+	} else {
+		WARN_PRINT("Cannot verify bone index...");
+		bone2d_index = p_bone_idx;
+	}
+
+	notify_property_list_changed();
+}
+
+int PhysicalBone2D::get_bone2d_index() const {
+	return bone2d_index;
+}
+
+void PhysicalBone2D::set_follow_bone_when_simulating(bool p_follow_bone) {
+	follow_bone_when_simulating = p_follow_bone;
+
+	if (_internal_simulate_physics) {
+		_stop_physics_simulation();
+		_start_physics_simulation();
+	}
+}
+
+bool PhysicalBone2D::get_follow_bone_when_simulating() const {
+	return follow_bone_when_simulating;
+}
+
+void PhysicalBone2D::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("get_joint"), &PhysicalBone2D::get_joint);
+	ClassDB::bind_method(D_METHOD("get_auto_configure_joint"), &PhysicalBone2D::get_auto_configure_joint);
+	ClassDB::bind_method(D_METHOD("set_auto_configure_joint", "auto_configure_joint"), &PhysicalBone2D::set_auto_configure_joint);
+
+	ClassDB::bind_method(D_METHOD("set_simulate_physics", "simulate_physics"), &PhysicalBone2D::set_simulate_physics);
+	ClassDB::bind_method(D_METHOD("get_simulate_physics"), &PhysicalBone2D::get_simulate_physics);
+	ClassDB::bind_method(D_METHOD("is_simulating_physics"), &PhysicalBone2D::is_simulating_physics);
+
+	ClassDB::bind_method(D_METHOD("set_bone2d_nodepath", "nodepath"), &PhysicalBone2D::set_bone2d_nodepath);
+	ClassDB::bind_method(D_METHOD("get_bone2d_nodepath"), &PhysicalBone2D::get_bone2d_nodepath);
+	ClassDB::bind_method(D_METHOD("set_bone2d_index", "bone_index"), &PhysicalBone2D::set_bone2d_index);
+	ClassDB::bind_method(D_METHOD("get_bone2d_index"), &PhysicalBone2D::get_bone2d_index);
+	ClassDB::bind_method(D_METHOD("set_follow_bone_when_simulating", "follow_bone"), &PhysicalBone2D::set_follow_bone_when_simulating);
+	ClassDB::bind_method(D_METHOD("get_follow_bone_when_simulating"), &PhysicalBone2D::get_follow_bone_when_simulating);
+
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "bone2d_nodepath", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Bone2D"), "set_bone2d_nodepath", "get_bone2d_nodepath");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "bone2d_index", PROPERTY_HINT_RANGE, "-1, 1000, 1"), "set_bone2d_index", "get_bone2d_index");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "auto_configure_joint"), "set_auto_configure_joint", "get_auto_configure_joint");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "simulate_physics"), "set_simulate_physics", "get_simulate_physics");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "follow_bone_when_simulating"), "set_follow_bone_when_simulating", "get_follow_bone_when_simulating");
+}
+
+PhysicalBone2D::PhysicalBone2D() {
+	// Stop the RigidBody from executing its force integration.
+	PhysicsServer2D::get_singleton()->body_set_collision_layer(get_rid(), 0);
+	PhysicsServer2D::get_singleton()->body_set_collision_mask(get_rid(), 0);
+	PhysicsServer2D::get_singleton()->body_set_mode(get_rid(), PhysicsServer2D::BodyMode::BODY_MODE_STATIC);
+
+	child_joint = nullptr;
+}
+
+PhysicalBone2D::~PhysicalBone2D() {
+}
diff --git a/scene/2d/physical_bone_2d.h b/scene/2d/physical_bone_2d.h
new file mode 100644
index 0000000000..d650a0426f
--- /dev/null
+++ b/scene/2d/physical_bone_2d.h
@@ -0,0 +1,88 @@
+/*************************************************************************/
+/*  physical_bone_2d.h                                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef PHYSICAL_BONE_2D_H
+#define PHYSICAL_BONE_2D_H
+
+#include "scene/2d/joints_2d.h"
+#include "scene/2d/physics_body_2d.h"
+
+#include "scene/2d/skeleton_2d.h"
+
+class PhysicalBone2D : public RigidBody2D {
+	GDCLASS(PhysicalBone2D, RigidBody2D);
+
+protected:
+	void _notification(int p_what);
+	static void _bind_methods();
+
+private:
+	Skeleton2D *parent_skeleton;
+	int bone2d_index = -1;
+	NodePath bone2d_nodepath;
+	bool follow_bone_when_simulating = false;
+
+	Joint2D *child_joint;
+	bool auto_configure_joint = true;
+
+	bool simulate_physics = false;
+	bool _internal_simulate_physics = false;
+
+	void _find_skeleton_parent();
+	void _find_joint_child();
+	void _auto_configure_joint();
+
+	void _start_physics_simulation();
+	void _stop_physics_simulation();
+	void _position_at_bone2d();
+
+public:
+	Joint2D *get_joint() const;
+	bool get_auto_configure_joint() const;
+	void set_auto_configure_joint(bool p_auto_configure);
+
+	void set_simulate_physics(bool p_simulate);
+	bool get_simulate_physics() const;
+	bool is_simulating_physics() const;
+
+	void set_bone2d_nodepath(const NodePath &p_nodepath);
+	NodePath get_bone2d_nodepath() const;
+	void set_bone2d_index(int p_bone_idx);
+	int get_bone2d_index() const;
+	void set_follow_bone_when_simulating(bool p_follow);
+	bool get_follow_bone_when_simulating() const;
+
+	TypedArray<String> get_configuration_warnings() const override;
+
+	PhysicalBone2D();
+	~PhysicalBone2D();
+};
+
+#endif // PHYSICAL_BONE_2D_H
diff --git a/scene/2d/skeleton_2d.cpp b/scene/2d/skeleton_2d.cpp
index 22180797f0..c5ad3dde39 100644
--- a/scene/2d/skeleton_2d.cpp
+++ b/scene/2d/skeleton_2d.cpp
@@ -30,6 +30,69 @@
 
 #include "skeleton_2d.h"
 
+#include "scene/resources/skeleton_modification_2d.h"
+
+#ifdef TOOLS_ENABLED
+#include "editor/editor_settings.h"
+#include "editor/plugins/canvas_item_editor_plugin.h"
+#endif //TOOLS_ENABLED
+
+bool Bone2D::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path.begins_with("auto_calculate_length_and_angle")) {
+		set_autocalculate_length_and_angle(p_value);
+	} else if (path.begins_with("length")) {
+		set_length(p_value);
+	} else if (path.begins_with("bone_angle")) {
+		set_bone_angle(Math::deg2rad(float(p_value)));
+	} else if (path.begins_with("default_length")) {
+		set_length(p_value);
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path.begins_with("editor_settings/show_bone_gizmo")) {
+		_editor_set_show_bone_gizmo(p_value);
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+bool Bone2D::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path.begins_with("auto_calculate_length_and_angle")) {
+		r_ret = get_autocalculate_length_and_angle();
+	} else if (path.begins_with("length")) {
+		r_ret = get_length();
+	} else if (path.begins_with("bone_angle")) {
+		r_ret = Math::rad2deg(get_bone_angle());
+	} else if (path.begins_with("default_length")) {
+		r_ret = get_length();
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path.begins_with("editor_settings/show_bone_gizmo")) {
+		r_ret = _editor_get_show_bone_gizmo();
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+void Bone2D::_get_property_list(List<PropertyInfo> *p_list) const {
+	p_list->push_back(PropertyInfo(Variant::BOOL, "auto_calculate_length_and_angle", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	if (!autocalculate_length_and_angle) {
+		p_list->push_back(PropertyInfo(Variant::FLOAT, "length", PROPERTY_HINT_RANGE, "1, 1024, 1", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::FLOAT, "bone_angle", PROPERTY_HINT_RANGE, "-360, 360, 0.01", PROPERTY_USAGE_DEFAULT));
+	}
+
+#ifdef TOOLS_ENABLED
+	p_list->push_back(PropertyInfo(Variant::BOOL, "editor_settings/show_bone_gizmo", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+#endif // TOOLS_ENABLED
+}
+
 void Bone2D::_notification(int p_what) {
 	if (p_what == NOTIFICATION_ENTER_TREE) {
 		Node *parent = get_parent();
@@ -53,19 +116,54 @@ void Bone2D::_notification(int p_what) {
 			skeleton->bones.push_back(bone);
 			skeleton->_make_bone_setup_dirty();
 		}
+
+		cache_transform = get_transform();
+		copy_transform_to_cache = true;
+
+#ifdef TOOLS_ENABLED
+		// Only draw the gizmo in the editor!
+		if (Engine::get_singleton()->is_editor_hint() == false) {
+			return;
+		}
+
+		update();
+#endif // TOOLS_ENABLED
 	}
-	if (p_what == NOTIFICATION_LOCAL_TRANSFORM_CHANGED) {
+
+	else if (p_what == NOTIFICATION_LOCAL_TRANSFORM_CHANGED) {
 		if (skeleton) {
 			skeleton->_make_transform_dirty();
 		}
+		if (copy_transform_to_cache) {
+			cache_transform = get_transform();
+		}
+#ifdef TOOLS_ENABLED
+		// Only draw the gizmo in the editor!
+		if (Engine::get_singleton()->is_editor_hint() == false) {
+			return;
+		}
+
+		update();
+
+		if (get_parent()) {
+			Bone2D *parent_bone = Object::cast_to<Bone2D>(get_parent());
+			if (parent_bone) {
+				parent_bone->update();
+			}
+		}
+#endif // TOOLS_ENABLED
 	}
-	if (p_what == NOTIFICATION_MOVED_IN_PARENT) {
+
+	else if (p_what == NOTIFICATION_MOVED_IN_PARENT) {
 		if (skeleton) {
 			skeleton->_make_bone_setup_dirty();
 		}
+		if (copy_transform_to_cache) {
+			cache_transform = get_transform();
+		}
 	}
 
-	if (p_what == NOTIFICATION_EXIT_TREE) {
+	else if (p_what == NOTIFICATION_EXIT_TREE) {
 		if (skeleton) {
 			for (int i = 0; i < skeleton->bones.size(); i++) {
 				if (skeleton->bones[i].bone == this) {
@@ -77,9 +175,200 @@ void Bone2D::_notification(int p_what) {
 			skeleton = nullptr;
 		}
 		parent_bone = nullptr;
+		set_transform(cache_transform);
 	}
+
+	else if (p_what == NOTIFICATION_READY) {
+		if (autocalculate_length_and_angle) {
+			calculate_length_and_rotation();
+		}
+	}
+#ifdef TOOLS_ENABLED
+	else if (p_what == NOTIFICATION_EDITOR_PRE_SAVE || p_what == NOTIFICATION_EDITOR_POST_SAVE) {
+		Transform2D tmp_trans = get_transform();
+		set_transform(cache_transform);
+		cache_transform = tmp_trans;
+	}
+	// Bone2D Editor gizmo drawing:
+#ifndef _MSC_VER
+#warning TODO Bone2D gizmo drawing needs to be moved to an editor plugin
+#endif
+	else if (p_what == NOTIFICATION_DRAW) {
+		// Only draw the gizmo in the editor!
+		if (Engine::get_singleton()->is_editor_hint() == false) {
+			return;
+		}
+
+		if (editor_gizmo_rid.is_null()) {
+			editor_gizmo_rid = RenderingServer::get_singleton()->canvas_item_create();
+			RenderingServer::get_singleton()->canvas_item_set_parent(editor_gizmo_rid, get_canvas_item());
+			RenderingServer::get_singleton()->canvas_item_set_z_as_relative_to_parent(editor_gizmo_rid, true);
+			RenderingServer::get_singleton()->canvas_item_set_z_index(editor_gizmo_rid, 10);
+		}
+		RenderingServer::get_singleton()->canvas_item_clear(editor_gizmo_rid);
+
+		if (!_editor_show_bone_gizmo) {
+			return;
+		}
+
+		// Undo scaling
+		Transform2D editor_gizmo_trans = Transform2D();
+		editor_gizmo_trans.set_scale(Vector2(1, 1) / get_global_scale());
+		RenderingServer::get_singleton()->canvas_item_set_transform(editor_gizmo_rid, editor_gizmo_trans);
+
+		Color bone_color1 = EditorSettings::get_singleton()->get("editors/2d/bone_color1");
+		Color bone_color2 = EditorSettings::get_singleton()->get("editors/2d/bone_color2");
+		Color bone_ik_color = EditorSettings::get_singleton()->get("editors/2d/bone_ik_color");
+		Color bone_outline_color = EditorSettings::get_singleton()->get("editors/2d/bone_outline_color");
+		Color bone_selected_color = EditorSettings::get_singleton()->get("editors/2d/bone_selected_color");
+
+		bool Bone2D_found = false;
+		for (int i = 0; i < get_child_count(); i++) {
+			Bone2D *child_node = nullptr;
+			child_node = Object::cast_to<Bone2D>(get_child(i));
+			if (!child_node) {
+				continue;
+			}
+			Bone2D_found = true;
+
+			Vector<Vector2> bone_shape;
+			Vector<Vector2> bone_shape_outline;
+
+			_editor_get_bone_shape(&bone_shape, &bone_shape_outline, child_node);
+
+			Vector<Color> colors;
+			if (has_meta("_local_pose_override_enabled_")) {
+				colors.push_back(bone_ik_color);
+				colors.push_back(bone_ik_color);
+				colors.push_back(bone_ik_color);
+				colors.push_back(bone_ik_color);
+			} else {
+				colors.push_back(bone_color1);
+				colors.push_back(bone_color2);
+				colors.push_back(bone_color1);
+				colors.push_back(bone_color2);
+			}
+
+			Vector<Color> outline_colors;
+			if (CanvasItemEditor::get_singleton()->editor_selection->is_selected(this)) {
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+			} else {
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+			}
+
+			RenderingServer::get_singleton()->canvas_item_add_polygon(editor_gizmo_rid, bone_shape_outline, outline_colors);
+			RenderingServer::get_singleton()->canvas_item_add_polygon(editor_gizmo_rid, bone_shape, colors);
+		}
+
+		if (!Bone2D_found) {
+			Vector<Vector2> bone_shape;
+			Vector<Vector2> bone_shape_outline;
+
+			_editor_get_bone_shape(&bone_shape, &bone_shape_outline, nullptr);
+
+			Vector<Color> colors;
+			if (has_meta("_local_pose_override_enabled_")) {
+				colors.push_back(bone_ik_color);
+				colors.push_back(bone_ik_color);
+				colors.push_back(bone_ik_color);
+				colors.push_back(bone_ik_color);
+			} else {
+				colors.push_back(bone_color1);
+				colors.push_back(bone_color2);
+				colors.push_back(bone_color1);
+				colors.push_back(bone_color2);
+			}
+
+			Vector<Color> outline_colors;
+			if (CanvasItemEditor::get_singleton()->editor_selection->is_selected(this)) {
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+				outline_colors.push_back(bone_selected_color);
+			} else {
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+				outline_colors.push_back(bone_outline_color);
+			}
+
+			RenderingServer::get_singleton()->canvas_item_add_polygon(editor_gizmo_rid, bone_shape_outline, outline_colors);
+			RenderingServer::get_singleton()->canvas_item_add_polygon(editor_gizmo_rid, bone_shape, colors);
+		}
+	}
+#endif // TOOLS_ENALBED
 }
 
+#ifdef TOOLS_ENABLED
+bool Bone2D::_editor_get_bone_shape(Vector<Vector2> *p_shape, Vector<Vector2> *p_outline_shape, Bone2D *p_other_bone) {
+	int bone_width = EditorSettings::get_singleton()->get("editors/2d/bone_width");
+	int bone_outline_width = EditorSettings::get_singleton()->get("editors/2d/bone_outline_size");
+
+	if (!is_inside_tree()) {
+		return false; //may have been removed
+	}
+	if (!p_other_bone && length <= 0) {
+		return false;
+	}
+
+	Vector2 rel;
+	if (p_other_bone) {
+		rel = (p_other_bone->get_global_transform().get_origin() - get_global_transform().get_origin());
+		rel = rel.rotated(-get_global_rotation()); // Undo Bone2D node's rotation so its drawn correctly regardless of the node's rotation
+	} else {
+		float angle_to_use = get_rotation() + bone_angle;
+		rel = Vector2(cos(angle_to_use), sin(angle_to_use)) * (length * MIN(get_global_scale().x, get_global_scale().y));
+		rel = rel.rotated(-get_rotation()); // Undo Bone2D node's rotation so its drawn correctly regardless of the node's rotation
+	}
+
+	Vector2 relt = rel.rotated(Math_PI * 0.5).normalized() * bone_width;
+	Vector2 reln = rel.normalized();
+	Vector2 reltn = relt.normalized();
+
+	if (p_shape) {
+		p_shape->clear();
+		p_shape->push_back(Vector2(0, 0));
+		p_shape->push_back(rel * 0.2 + relt);
+		p_shape->push_back(rel);
+		p_shape->push_back(rel * 0.2 - relt);
+	}
+
+	if (p_outline_shape) {
+		p_outline_shape->clear();
+		p_outline_shape->push_back((-reln - reltn) * bone_outline_width);
+		p_outline_shape->push_back((-reln + reltn) * bone_outline_width);
+		p_outline_shape->push_back(rel * 0.2 + relt + reltn * bone_outline_width);
+		p_outline_shape->push_back(rel + (reln + reltn) * bone_outline_width);
+		p_outline_shape->push_back(rel + (reln - reltn) * bone_outline_width);
+		p_outline_shape->push_back(rel * 0.2 - relt - reltn * bone_outline_width);
+	}
+	return true;
+}
+
+void Bone2D::_editor_set_show_bone_gizmo(bool p_show_gizmo) {
+	_editor_show_bone_gizmo = p_show_gizmo;
+	update();
+}
+
+bool Bone2D::_editor_get_show_bone_gizmo() const {
+	return _editor_show_bone_gizmo;
+}
+#endif // TOOLS_ENABLED
+
 void Bone2D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_rest", "rest"), &Bone2D::set_rest);
 	ClassDB::bind_method(D_METHOD("get_rest"), &Bone2D::get_rest);
@@ -90,8 +379,14 @@ void Bone2D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_default_length", "default_length"), &Bone2D::set_default_length);
 	ClassDB::bind_method(D_METHOD("get_default_length"), &Bone2D::get_default_length);
 
+	ClassDB::bind_method(D_METHOD("set_autocalculate_length_and_angle", "auto_calculate"), &Bone2D::set_autocalculate_length_and_angle);
+	ClassDB::bind_method(D_METHOD("get_autocalculate_length_and_angle"), &Bone2D::get_autocalculate_length_and_angle);
+	ClassDB::bind_method(D_METHOD("set_length", "length"), &Bone2D::set_length);
+	ClassDB::bind_method(D_METHOD("get_length"), &Bone2D::get_length);
+	ClassDB::bind_method(D_METHOD("set_bone_angle", "angle"), &Bone2D::set_bone_angle);
+	ClassDB::bind_method(D_METHOD("get_bone_angle"), &Bone2D::get_bone_angle);
+
 	ADD_PROPERTY(PropertyInfo(Variant::TRANSFORM2D, "rest"), "set_rest", "get_rest");
-	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "default_length", PROPERTY_HINT_RANGE, "1,1024,1"), "set_default_length", "get_default_length");
 }
 
 void Bone2D::set_rest(const Transform2D &p_rest) {
@@ -119,12 +414,14 @@ void Bone2D::apply_rest() {
 	set_transform(rest);
 }
 
-void Bone2D::set_default_length(real_t p_length) {
-	default_length = p_length;
+void Bone2D::set_default_length(float p_length) {
+	WARN_DEPRECATED_MSG("set_default_length is deprecated. Please use set_length instead!");
+	set_length(p_length);
 }
 
-real_t Bone2D::get_default_length() const {
-	return default_length;
+float Bone2D::get_default_length() const {
+	WARN_DEPRECATED_MSG("get_default_length is deprecated. Please use get_length instead!");
+	return get_length();
 }
 
 int Bone2D::get_index_in_skeleton() const {
@@ -150,16 +447,121 @@ TypedArray<String> Bone2D::get_configuration_warnings() const {
 	return warnings;
 }
 
+void Bone2D::calculate_length_and_rotation() {
+	// if there is at least a single child Bone2D node, we can calculate
+	// the length and direction. We will always just use the first Bone2D for this.
+	bool calculated = false;
+	int child_count = get_child_count();
+	if (child_count > 0) {
+		for (int i = 0; i < child_count; i++) {
+			Bone2D *child = Object::cast_to<Bone2D>(get_child(i));
+			if (child) {
+				Vector2 child_local_pos = to_local(child->get_global_transform().get_origin());
+				length = child_local_pos.length();
+				bone_angle = Math::atan2(child_local_pos.normalized().y, child_local_pos.normalized().x);
+				calculated = true;
+				break;
+			}
+		}
+	}
+	if (calculated) {
+		return; // Finished!
+	} else {
+		WARN_PRINT("No Bone2D children of node " + get_name() + ". Cannot calculate bone length or angle reliably.\nUsing transform rotation for bone angle");
+		bone_angle = get_transform().get_rotation();
+		return;
+	}
+}
+
+void Bone2D::set_autocalculate_length_and_angle(bool p_autocalculate) {
+	autocalculate_length_and_angle = p_autocalculate;
+	if (autocalculate_length_and_angle) {
+		calculate_length_and_rotation();
+	}
+	notify_property_list_changed();
+}
+
+bool Bone2D::get_autocalculate_length_and_angle() const {
+	return autocalculate_length_and_angle;
+}
+
+void Bone2D::set_length(float p_length) {
+	length = p_length;
+
+#ifdef TOOLS_ENABLED
+	update();
+#endif // TOOLS_ENABLED
+}
+
+float Bone2D::get_length() const {
+	return length;
+}
+
+void Bone2D::set_bone_angle(float p_angle) {
+	bone_angle = p_angle;
+
+#ifdef TOOLS_ENABLED
+	update();
+#endif // TOOLS_ENABLED
+}
+
+float Bone2D::get_bone_angle() const {
+	return bone_angle;
+}
+
 Bone2D::Bone2D() {
+	skeleton = nullptr;
+	parent_bone = nullptr;
+	skeleton_index = -1;
+	length = 16;
+	bone_angle = 0;
+	autocalculate_length_and_angle = true;
 	set_notify_local_transform(true);
 	//this is a clever hack so the bone knows no rest has been set yet, allowing to show an error.
 	for (int i = 0; i < 3; i++) {
 		rest[i] = Vector2(0, 0);
 	}
+	copy_transform_to_cache = true;
+}
+
+Bone2D::~Bone2D() {
+#ifdef TOOLS_ENABLED
+	if (!editor_gizmo_rid.is_null()) {
+		RenderingServer::get_singleton()->free(editor_gizmo_rid);
+	}
+#endif // TOOLS_ENABLED
 }
 
 //////////////////////////////////////
 
+bool Skeleton2D::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path.begins_with("modification_stack")) {
+		set_modification_stack(p_value);
+		return true;
+	}
+	return true;
+}
+
+bool Skeleton2D::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path.begins_with("modification_stack")) {
+		r_ret = get_modification_stack();
+		return true;
+	}
+	return true;
+}
+
+void Skeleton2D::_get_property_list(List<PropertyInfo> *p_list) const {
+	p_list->push_back(
+			PropertyInfo(Variant::OBJECT, "modification_stack",
+					PROPERTY_HINT_RESOURCE_TYPE,
+					"SkeletonModificationStack2D",
+					PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_DEFERRED_SET_RESOURCE | PROPERTY_USAGE_DO_NOT_SHARE_ON_DUPLICATE));
+}
+
 void Skeleton2D::_make_bone_setup_dirty() {
 	if (bone_setup_dirty) {
 		return;
@@ -189,6 +591,8 @@ void Skeleton2D::_update_bone_setup() {
 		} else {
 			bones.write[i].parent_index = -1;
 		}
+
+		bones.write[i].local_pose_override = bones[i].bone->get_skeleton_rest();
 	}
 
 	transform_dirty = true;
@@ -257,19 +661,121 @@ void Skeleton2D::_notification(int p_what) {
 		if (transform_dirty) {
 			_update_transform();
 		}
-
 		request_ready();
 	}
 
 	if (p_what == NOTIFICATION_TRANSFORM_CHANGED) {
 		RS::get_singleton()->skeleton_set_base_transform_2d(skeleton, get_global_transform());
+	} else if (p_what == NOTIFICATION_INTERNAL_PROCESS) {
+		if (modification_stack.is_valid()) {
+			execute_modifications(get_process_delta_time(), SkeletonModificationStack2D::EXECUTION_MODE::execution_mode_process);
+		}
+	} else if (p_what == NOTIFICATION_INTERNAL_PHYSICS_PROCESS) {
+		if (modification_stack.is_valid()) {
+			execute_modifications(get_physics_process_delta_time(), SkeletonModificationStack2D::EXECUTION_MODE::execution_mode_physics_process);
+		}
 	}
+#ifdef TOOLS_ENABLED
+	else if (p_what == NOTIFICATION_DRAW) {
+		if (Engine::get_singleton()->is_editor_hint()) {
+			if (modification_stack.is_valid()) {
+				modification_stack->draw_editor_gizmos();
+			}
+		}
+	}
+#endif // TOOLS_ENABLED
 }
 
 RID Skeleton2D::get_skeleton() const {
 	return skeleton;
 }
 
+void Skeleton2D::set_bone_local_pose_override(int p_bone_idx, Transform2D p_override, float p_amount, bool p_persistent) {
+	ERR_FAIL_INDEX_MSG(p_bone_idx, bones.size(), "Bone index is out of range!");
+	bones.write[p_bone_idx].local_pose_override = p_override;
+	bones.write[p_bone_idx].local_pose_override_amount = p_amount;
+	bones.write[p_bone_idx].local_pose_override_persistent = p_persistent;
+}
+
+Transform2D Skeleton2D::get_bone_local_pose_override(int p_bone_idx) {
+	ERR_FAIL_INDEX_V_MSG(p_bone_idx, bones.size(), Transform2D(), "Bone index is out of range!");
+	return bones[p_bone_idx].local_pose_override;
+}
+
+void Skeleton2D::set_modification_stack(Ref<SkeletonModificationStack2D> p_stack) {
+	if (modification_stack.is_valid()) {
+		modification_stack->is_setup = false;
+		modification_stack->set_skeleton(nullptr);
+
+		set_process_internal(false);
+		set_physics_process_internal(false);
+	}
+	modification_stack = p_stack;
+	if (modification_stack.is_valid()) {
+		modification_stack->set_skeleton(this);
+		modification_stack->setup();
+
+		set_process_internal(true);
+		set_physics_process_internal(true);
+
+#ifdef TOOLS_ENABLED
+		modification_stack->set_editor_gizmos_dirty(true);
+#endif // TOOLS_ENABLED
+	}
+}
+
+Ref<SkeletonModificationStack2D> Skeleton2D::get_modification_stack() const {
+	return modification_stack;
+}
+
+void Skeleton2D::execute_modifications(float p_delta, int p_execution_mode) {
+	if (!modification_stack.is_valid()) {
+		return;
+	}
+
+	// Do not cache the transform changes caused by the modifications!
+	for (int i = 0; i < bones.size(); i++) {
+		bones[i].bone->copy_transform_to_cache = false;
+	}
+
+	if (modification_stack->skeleton != this) {
+		modification_stack->set_skeleton(this);
+	}
+
+	modification_stack->execute(p_delta, p_execution_mode);
+
+	// Only apply the local pose override on _process. Otherwise, just calculate the local_pose_override and reset the transform.
+	if (p_execution_mode == SkeletonModificationStack2D::EXECUTION_MODE::execution_mode_process) {
+		for (int i = 0; i < bones.size(); i++) {
+			if (bones[i].local_pose_override_amount > 0) {
+				bones[i].bone->set_meta("_local_pose_override_enabled_", true);
+
+				Transform2D final_trans = bones[i].bone->cache_transform;
+				final_trans = final_trans.interpolate_with(bones[i].local_pose_override, bones[i].local_pose_override_amount);
+				bones[i].bone->set_transform(final_trans);
+				bones[i].bone->propagate_call("force_update_transform");
+
+				if (bones[i].local_pose_override_persistent) {
+					bones.write[i].local_pose_override_amount = 0.0;
+				}
+			} else {
+				// TODO: see if there is a way to undo the override without having to resort to setting every bone's transform.
+				bones[i].bone->remove_meta("_local_pose_override_enabled_");
+				bones[i].bone->set_transform(bones[i].bone->cache_transform);
+			}
+		}
+	}
+
+	// Cache any future transform changes
+	for (int i = 0; i < bones.size(); i++) {
+		bones[i].bone->copy_transform_to_cache = true;
+	}
+
+#ifdef TOOLS_ENABLED
+	modification_stack->set_editor_gizmos_dirty(true);
+#endif // TOOLS_ENABLED
+}
+
 void Skeleton2D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("_update_bone_setup"), &Skeleton2D::_update_bone_setup);
 	ClassDB::bind_method(D_METHOD("_update_transform"), &Skeleton2D::_update_transform);
@@ -279,6 +785,13 @@ void Skeleton2D::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("get_skeleton"), &Skeleton2D::get_skeleton);
 
+	ClassDB::bind_method(D_METHOD("set_modification_stack", "modification_stack"), &Skeleton2D::set_modification_stack);
+	ClassDB::bind_method(D_METHOD("get_modification_stack"), &Skeleton2D::get_modification_stack);
+	ClassDB::bind_method(D_METHOD("execute_modifications", "execution_mode", "execution_mode"), &Skeleton2D::execute_modifications);
+
+	ClassDB::bind_method(D_METHOD("set_bone_local_pose_override", "bone_idx", "override_pose", "strength", "persistent"), &Skeleton2D::set_bone_local_pose_override);
+	ClassDB::bind_method(D_METHOD("get_bone_local_pose_override", "bone_idx"), &Skeleton2D::get_bone_local_pose_override);
+
 	ADD_SIGNAL(MethodInfo("bone_setup_changed"));
 }
 
diff --git a/scene/2d/skeleton_2d.h b/scene/2d/skeleton_2d.h
index fd62b87bde..59bd711960 100644
--- a/scene/2d/skeleton_2d.h
+++ b/scene/2d/skeleton_2d.h
@@ -32,6 +32,7 @@
 #define SKELETON_2D_H
 
 #include "scene/2d/node_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
 
 class Skeleton2D;
 
@@ -46,15 +47,32 @@ class Bone2D : public Node2D {
 	Bone2D *parent_bone = nullptr;
 	Skeleton2D *skeleton = nullptr;
 	Transform2D rest;
-	real_t default_length = 16.0;
+
+	bool autocalculate_length_and_angle = true;
+	float length = 16;
+	float bone_angle = 0;
 
 	int skeleton_index = -1;
 
+	void calculate_length_and_rotation();
+
+#ifdef TOOLS_ENABLED
+	RID editor_gizmo_rid;
+	bool _editor_get_bone_shape(Vector<Vector2> *p_shape, Vector<Vector2> *p_outline_shape, Bone2D *p_other_bone);
+	bool _editor_show_bone_gizmo = true;
+#endif // TOOLS ENABLED
+
 protected:
 	void _notification(int p_what);
 	static void _bind_methods();
+	bool _set(const StringName &p_path, const Variant &p_value);
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	void _get_property_list(List<PropertyInfo> *p_list) const;
 
 public:
+	Transform2D cache_transform;
+	bool copy_transform_to_cache = true;
+
 	void set_rest(const Transform2D &p_rest);
 	Transform2D get_rest() const;
 	void apply_rest();
@@ -65,11 +83,26 @@ public:
 	void set_default_length(real_t p_length);
 	real_t get_default_length() const;
 
+	void set_autocalculate_length_and_angle(bool p_autocalculate);
+	bool get_autocalculate_length_and_angle() const;
+	void set_length(float p_length);
+	float get_length() const;
+	void set_bone_angle(float p_angle);
+	float get_bone_angle() const;
+
 	int get_index_in_skeleton() const;
 
+#ifdef TOOLS_ENABLED
+	void _editor_set_show_bone_gizmo(bool p_show_gizmo);
+	bool _editor_get_show_bone_gizmo() const;
+#endif // TOOLS_ENABLED
+
 	Bone2D();
+	~Bone2D();
 };
 
+class SkeletonModificationStack2D;
+
 class Skeleton2D : public Node2D {
 	GDCLASS(Skeleton2D, Node2D);
 
@@ -86,6 +119,11 @@ class Skeleton2D : public Node2D {
 		int parent_index = 0;
 		Transform2D accum_transform;
 		Transform2D rest_inverse;
+
+		//Transform2D local_pose_cache;
+		Transform2D local_pose_override;
+		float local_pose_override_amount = 0;
+		bool local_pose_override_persistent = false;
 	};
 
 	Vector<Bone> bones;
@@ -100,15 +138,28 @@ class Skeleton2D : public Node2D {
 
 	RID skeleton;
 
+	Ref<SkeletonModificationStack2D> modification_stack;
+
 protected:
 	void _notification(int p_what);
 	static void _bind_methods();
+	bool _set(const StringName &p_path, const Variant &p_value);
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	void _get_property_list(List<PropertyInfo> *p_list) const;
 
 public:
 	int get_bone_count() const;
 	Bone2D *get_bone(int p_idx);
 
 	RID get_skeleton() const;
+
+	void set_bone_local_pose_override(int p_bone_idx, Transform2D p_override, float p_amount, bool p_persistent = true);
+	Transform2D get_bone_local_pose_override(int p_bone_idx);
+
+	Ref<SkeletonModificationStack2D> get_modification_stack() const;
+	void set_modification_stack(Ref<SkeletonModificationStack2D> p_stack);
+	void execute_modifications(float p_delta, int p_execution_mode);
+
 	Skeleton2D();
 	~Skeleton2D();
 };
diff --git a/scene/main/node.cpp b/scene/main/node.cpp
index dc7057f339..c7c782b992 100644
--- a/scene/main/node.cpp
+++ b/scene/main/node.cpp
@@ -2830,6 +2830,9 @@ void Node::_bind_methods() {
 	BIND_CONSTANT(NOTIFICATION_INTERNAL_PHYSICS_PROCESS);
 	BIND_CONSTANT(NOTIFICATION_POST_ENTER_TREE);
 
+	BIND_CONSTANT(NOTIFICATION_EDITOR_PRE_SAVE);
+	BIND_CONSTANT(NOTIFICATION_EDITOR_POST_SAVE);
+
 	BIND_CONSTANT(NOTIFICATION_WM_MOUSE_ENTER);
 	BIND_CONSTANT(NOTIFICATION_WM_MOUSE_EXIT);
 	BIND_CONSTANT(NOTIFICATION_WM_WINDOW_FOCUS_IN);
diff --git a/scene/main/node.h b/scene/main/node.h
index 6ca2317d9e..04897cf2e8 100644
--- a/scene/main/node.h
+++ b/scene/main/node.h
@@ -253,6 +253,10 @@ public:
 		NOTIFICATION_APPLICATION_FOCUS_IN = MainLoop::NOTIFICATION_APPLICATION_FOCUS_IN,
 		NOTIFICATION_APPLICATION_FOCUS_OUT = MainLoop::NOTIFICATION_APPLICATION_FOCUS_OUT,
 		NOTIFICATION_TEXT_SERVER_CHANGED = MainLoop::NOTIFICATION_TEXT_SERVER_CHANGED,
+
+		// Editor specific node notifications
+		NOTIFICATION_EDITOR_PRE_SAVE = 9001,
+		NOTIFICATION_EDITOR_POST_SAVE = 9002,
 	};
 
 	/* NODE/TREE */
diff --git a/scene/register_scene_types.cpp b/scene/register_scene_types.cpp
index 94da5749fc..a99bb0211d 100644
--- a/scene/register_scene_types.cpp
+++ b/scene/register_scene_types.cpp
@@ -55,6 +55,7 @@
 #include "scene/2d/parallax_background.h"
 #include "scene/2d/parallax_layer.h"
 #include "scene/2d/path_2d.h"
+#include "scene/2d/physical_bone_2d.h"
 #include "scene/2d/physics_body_2d.h"
 #include "scene/2d/polygon_2d.h"
 #include "scene/2d/position_2d.h"
@@ -160,6 +161,15 @@
 #include "scene/resources/rectangle_shape_2d.h"
 #include "scene/resources/resource_format_text.h"
 #include "scene/resources/segment_shape_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+#include "scene/resources/skeleton_modification_2d_ccdik.h"
+#include "scene/resources/skeleton_modification_2d_fabrik.h"
+#include "scene/resources/skeleton_modification_2d_jiggle.h"
+#include "scene/resources/skeleton_modification_2d_lookat.h"
+#include "scene/resources/skeleton_modification_2d_physicalbones.h"
+#include "scene/resources/skeleton_modification_2d_stackholder.h"
+#include "scene/resources/skeleton_modification_2d_twoboneik.h"
+#include "scene/resources/skeleton_modification_stack_2d.h"
 #include "scene/resources/sky.h"
 #include "scene/resources/sky_material.h"
 #include "scene/resources/sphere_shape_3d.h"
@@ -662,6 +672,18 @@ void register_scene_types() {
 	ClassDB::register_class<TouchScreenButton>();
 	ClassDB::register_class<RemoteTransform2D>();
 
+	ClassDB::register_class<SkeletonModificationStack2D>();
+	ClassDB::register_class<SkeletonModification2D>();
+	ClassDB::register_class<SkeletonModification2DLookAt>();
+	ClassDB::register_class<SkeletonModification2DCCDIK>();
+	ClassDB::register_class<SkeletonModification2DFABRIK>();
+	ClassDB::register_class<SkeletonModification2DJiggle>();
+	ClassDB::register_class<SkeletonModification2DTwoBoneIK>();
+	ClassDB::register_class<SkeletonModification2DStackHolder>();
+
+	ClassDB::register_class<PhysicalBone2D>();
+	ClassDB::register_class<SkeletonModification2DPhysicalBones>();
+
 	OS::get_singleton()->yield(); //may take time to init
 
 	/* REGISTER RESOURCES */
diff --git a/scene/resources/skeleton_modification_2d.cpp b/scene/resources/skeleton_modification_2d.cpp
new file mode 100644
index 0000000000..9b07293965
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d.cpp
@@ -0,0 +1,251 @@
+/*************************************************************************/
+/*  skeleton_modification_2d.cpp                                         */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_2d.h"
+#include "scene/2d/skeleton_2d.h"
+
+#include "scene/2d/collision_object_2d.h"
+#include "scene/2d/collision_shape_2d.h"
+#include "scene/2d/physical_bone_2d.h"
+
+#ifdef TOOLS_ENABLED
+#include "editor/editor_settings.h"
+#endif // TOOLS_ENABLED
+
+///////////////////////////////////////
+// Modification2D
+///////////////////////////////////////
+
+void SkeletonModification2D::_execute(float p_delta) {
+	call("_execute", p_delta);
+
+	if (!enabled) {
+		return;
+	}
+}
+
+void SkeletonModification2D::_setup_modification(SkeletonModificationStack2D *p_stack) {
+	stack = p_stack;
+	if (stack) {
+		is_setup = true;
+	} else {
+		WARN_PRINT("Could not setup modification with name " + get_name());
+	}
+
+	call("_setup_modification", p_stack);
+}
+
+void SkeletonModification2D::_draw_editor_gizmo() {
+	call("_draw_editor_gizmo");
+}
+
+void SkeletonModification2D::set_enabled(bool p_enabled) {
+	enabled = p_enabled;
+
+#ifdef TOOLS_ENABLED
+	if (editor_draw_gizmo) {
+		if (stack) {
+			stack->set_editor_gizmos_dirty(true);
+		}
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2D::get_enabled() {
+	return enabled;
+}
+
+float SkeletonModification2D::clamp_angle(float p_angle, float p_min_bound, float p_max_bound, bool p_invert) {
+	// Map to the 0 to 360 range (in radians though) instead of the -180 to 180 range.
+	if (p_angle < 0) {
+		p_angle = Math_TAU + p_angle;
+	}
+
+	// Make min and max in the range of 0 to 360 (in radians), and make sure they are in the right order
+	if (p_min_bound < 0) {
+		p_min_bound = Math_TAU + p_min_bound;
+	}
+	if (p_max_bound < 0) {
+		p_max_bound = Math_TAU + p_max_bound;
+	}
+	if (p_min_bound > p_max_bound) {
+		float tmp = p_min_bound;
+		p_min_bound = p_max_bound;
+		p_max_bound = tmp;
+	}
+
+	// Note: May not be the most optimal way to clamp, but it always constraints to the nearest angle.
+	if (p_invert == false) {
+		if (p_angle < p_min_bound || p_angle > p_max_bound) {
+			Vector2 min_bound_vec = Vector2(Math::cos(p_min_bound), Math::sin(p_min_bound));
+			Vector2 max_bound_vec = Vector2(Math::cos(p_max_bound), Math::sin(p_max_bound));
+			Vector2 angle_vec = Vector2(Math::cos(p_angle), Math::sin(p_angle));
+
+			if (angle_vec.distance_squared_to(min_bound_vec) <= angle_vec.distance_squared_to(max_bound_vec)) {
+				p_angle = p_min_bound;
+			} else {
+				p_angle = p_max_bound;
+			}
+		}
+	} else {
+		if (p_angle > p_min_bound && p_angle < p_max_bound) {
+			Vector2 min_bound_vec = Vector2(Math::cos(p_min_bound), Math::sin(p_min_bound));
+			Vector2 max_bound_vec = Vector2(Math::cos(p_max_bound), Math::sin(p_max_bound));
+			Vector2 angle_vec = Vector2(Math::cos(p_angle), Math::sin(p_angle));
+
+			if (angle_vec.distance_squared_to(min_bound_vec) <= angle_vec.distance_squared_to(max_bound_vec)) {
+				p_angle = p_min_bound;
+			} else {
+				p_angle = p_max_bound;
+			}
+		}
+	}
+	return p_angle;
+}
+
+void SkeletonModification2D::editor_draw_angle_constraints(Bone2D *p_operation_bone, float p_min_bound, float p_max_bound,
+		bool p_constraint_enabled, bool p_constraint_in_localspace, bool p_constraint_inverted) {
+	if (!p_operation_bone) {
+		return;
+	}
+
+	Color bone_ik_color = Color(1.0, 0.65, 0.0, 0.4);
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		bone_ik_color = EditorSettings::get_singleton()->get("editors/2d/bone_ik_color");
+	}
+#endif // TOOLS_ENABLED
+
+	float arc_angle_min = p_min_bound;
+	float arc_angle_max = p_max_bound;
+	if (arc_angle_min < 0) {
+		arc_angle_min = (Math_PI * 2) + arc_angle_min;
+	}
+	if (arc_angle_max < 0) {
+		arc_angle_max = (Math_PI * 2) + arc_angle_max;
+	}
+	if (arc_angle_min > arc_angle_max) {
+		float tmp = arc_angle_min;
+		arc_angle_min = arc_angle_max;
+		arc_angle_max = tmp;
+	}
+	arc_angle_min += p_operation_bone->get_bone_angle();
+	arc_angle_max += p_operation_bone->get_bone_angle();
+
+	if (p_constraint_enabled) {
+		if (p_constraint_in_localspace) {
+			Node *operation_bone_parent = p_operation_bone->get_parent();
+			Bone2D *operation_bone_parent_bone = Object::cast_to<Bone2D>(operation_bone_parent);
+
+			if (operation_bone_parent_bone) {
+				stack->skeleton->draw_set_transform(
+						stack->skeleton->get_global_transform().affine_inverse().xform(p_operation_bone->get_global_position()),
+						operation_bone_parent_bone->get_global_rotation() - stack->skeleton->get_global_rotation());
+			} else {
+				stack->skeleton->draw_set_transform(stack->skeleton->get_global_transform().affine_inverse().xform(p_operation_bone->get_global_position()));
+			}
+		} else {
+			stack->skeleton->draw_set_transform(stack->skeleton->get_global_transform().affine_inverse().xform(p_operation_bone->get_global_position()));
+		}
+
+		if (p_constraint_inverted) {
+			stack->skeleton->draw_arc(Vector2(0, 0), p_operation_bone->get_length(),
+					arc_angle_min + (Math_PI * 2), arc_angle_max, 32, bone_ik_color, 1.0);
+		} else {
+			stack->skeleton->draw_arc(Vector2(0, 0), p_operation_bone->get_length(),
+					arc_angle_min, arc_angle_max, 32, bone_ik_color, 1.0);
+		}
+		stack->skeleton->draw_line(Vector2(0, 0), Vector2(Math::cos(arc_angle_min), Math::sin(arc_angle_min)) * p_operation_bone->get_length(), bone_ik_color, 1.0);
+		stack->skeleton->draw_line(Vector2(0, 0), Vector2(Math::cos(arc_angle_max), Math::sin(arc_angle_max)) * p_operation_bone->get_length(), bone_ik_color, 1.0);
+
+	} else {
+		stack->skeleton->draw_set_transform(stack->skeleton->get_global_transform().affine_inverse().xform(p_operation_bone->get_global_position()));
+		stack->skeleton->draw_arc(Vector2(0, 0), p_operation_bone->get_length(), 0, Math_PI * 2, 32, bone_ik_color, 1.0);
+		stack->skeleton->draw_line(Vector2(0, 0), Vector2(1, 0) * p_operation_bone->get_length(), bone_ik_color, 1.0);
+	}
+}
+
+Ref<SkeletonModificationStack2D> SkeletonModification2D::get_modification_stack() {
+	return stack;
+}
+
+void SkeletonModification2D::set_is_setup(bool p_setup) {
+	is_setup = p_setup;
+}
+
+bool SkeletonModification2D::get_is_setup() const {
+	return is_setup;
+}
+
+void SkeletonModification2D::set_execution_mode(int p_mode) {
+	execution_mode = p_mode;
+}
+
+int SkeletonModification2D::get_execution_mode() const {
+	return execution_mode;
+}
+
+void SkeletonModification2D::set_editor_draw_gizmo(bool p_draw_gizmo) {
+	editor_draw_gizmo = p_draw_gizmo;
+#ifdef TOOLS_ENABLED
+	if (is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2D::get_editor_draw_gizmo() const {
+	return editor_draw_gizmo;
+}
+
+void SkeletonModification2D::_bind_methods() {
+	BIND_VMETHOD(MethodInfo("_execute", PropertyInfo(Variant::FLOAT, "delta")));
+	BIND_VMETHOD(MethodInfo("_setup_modification", PropertyInfo(Variant::OBJECT, "modification_stack", PROPERTY_HINT_RESOURCE_TYPE, "SkeletonModificationStack2D")));
+	BIND_VMETHOD(MethodInfo("_draw_editor_gizmo"));
+
+	ClassDB::bind_method(D_METHOD("set_enabled", "enabled"), &SkeletonModification2D::set_enabled);
+	ClassDB::bind_method(D_METHOD("get_enabled"), &SkeletonModification2D::get_enabled);
+	ClassDB::bind_method(D_METHOD("get_modification_stack"), &SkeletonModification2D::get_modification_stack);
+	ClassDB::bind_method(D_METHOD("set_is_setup", "is_setup"), &SkeletonModification2D::set_is_setup);
+	ClassDB::bind_method(D_METHOD("get_is_setup"), &SkeletonModification2D::get_is_setup);
+	ClassDB::bind_method(D_METHOD("set_execution_mode", "execution_mode"), &SkeletonModification2D::set_execution_mode);
+	ClassDB::bind_method(D_METHOD("get_execution_mode"), &SkeletonModification2D::get_execution_mode);
+	ClassDB::bind_method(D_METHOD("clamp_angle", "angle", "min", "max", "invert"), &SkeletonModification2D::clamp_angle);
+	ClassDB::bind_method(D_METHOD("set_editor_draw_gizmo", "draw_gizmo"), &SkeletonModification2D::set_editor_draw_gizmo);
+	ClassDB::bind_method(D_METHOD("get_editor_draw_gizmo"), &SkeletonModification2D::get_editor_draw_gizmo);
+
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "enabled"), "set_enabled", "get_enabled");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "execution_mode", PROPERTY_HINT_ENUM, "process, physics_process"), "set_execution_mode", "get_execution_mode");
+}
+
+SkeletonModification2D::SkeletonModification2D() {
+	stack = nullptr;
+	is_setup = false;
+}
diff --git a/scene/resources/skeleton_modification_2d.h b/scene/resources/skeleton_modification_2d.h
new file mode 100644
index 0000000000..18633e55cb
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d.h
@@ -0,0 +1,85 @@
+/*************************************************************************/
+/*  skeleton_modification_2d.h                                           */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATION2D_H
+#define SKELETONMODIFICATION2D_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_stack_2d.h"
+
+///////////////////////////////////////
+// SkeletonModification2D
+///////////////////////////////////////
+
+class SkeletonModificationStack2D;
+class Bone2D;
+
+class SkeletonModification2D : public Resource {
+	GDCLASS(SkeletonModification2D, Resource);
+	friend class Skeleton2D;
+	friend class Bone2D;
+
+protected:
+	static void _bind_methods();
+
+	SkeletonModificationStack2D *stack;
+	int execution_mode = 0; // 0 = process
+
+	bool enabled = true;
+	bool is_setup = false;
+
+	bool _print_execution_error(bool p_condition, String p_message);
+
+public:
+	virtual void _execute(float _delta);
+	virtual void _setup_modification(SkeletonModificationStack2D *p_stack);
+	virtual void _draw_editor_gizmo();
+
+	bool editor_draw_gizmo = false;
+	void set_editor_draw_gizmo(bool p_draw_gizmo);
+	bool get_editor_draw_gizmo() const;
+
+	void set_enabled(bool p_enabled);
+	bool get_enabled();
+
+	Ref<SkeletonModificationStack2D> get_modification_stack();
+	void set_is_setup(bool p_setup);
+	bool get_is_setup() const;
+
+	void set_execution_mode(int p_mode);
+	int get_execution_mode() const;
+
+	float clamp_angle(float p_angle, float p_min_bound, float p_max_bound, bool p_invert_clamp = false);
+	void editor_draw_angle_constraints(Bone2D *p_operation_bone, float p_min_bound, float p_max_bound, bool p_constraint_enabled, bool p_constraint_in_localspace, bool p_constraint_inverted);
+
+	SkeletonModification2D();
+};
+
+#endif // SKELETONMODIFICATION2D_H
diff --git a/scene/resources/skeleton_modification_2d_ccdik.cpp b/scene/resources/skeleton_modification_2d_ccdik.cpp
new file mode 100644
index 0000000000..7ea60e584e
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_ccdik.cpp
@@ -0,0 +1,545 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_ccdik.cpp                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_2d_ccdik.h"
+#include "scene/2d/skeleton_2d.h"
+
+#ifdef TOOLS_ENABLED
+#include "editor/editor_settings.h"
+#endif // TOOLS_ENABLED
+
+bool SkeletonModification2DCCDIK::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path.begins_with("joint_data/")) {
+		int which = path.get_slicec('/', 1).to_int();
+		String what = path.get_slicec('/', 2);
+		ERR_FAIL_INDEX_V(which, ccdik_data_chain.size(), false);
+
+		if (what == "bone2d_node") {
+			set_ccdik_joint_bone2d_node(which, p_value);
+		} else if (what == "bone_index") {
+			set_ccdik_joint_bone_index(which, p_value);
+		} else if (what == "rotate_from_joint") {
+			set_ccdik_joint_rotate_from_joint(which, p_value);
+		} else if (what == "enable_constraint") {
+			set_ccdik_joint_enable_constraint(which, p_value);
+		} else if (what == "constraint_angle_min") {
+			set_ccdik_joint_constraint_angle_min(which, Math::deg2rad(float(p_value)));
+		} else if (what == "constraint_angle_max") {
+			set_ccdik_joint_constraint_angle_max(which, Math::deg2rad(float(p_value)));
+		} else if (what == "constraint_angle_invert") {
+			set_ccdik_joint_constraint_angle_invert(which, p_value);
+		} else if (what == "constraint_in_localspace") {
+			set_ccdik_joint_constraint_in_localspace(which, p_value);
+		}
+
+#ifdef TOOLS_ENABLED
+		if (what.begins_with("editor_draw_gizmo")) {
+			set_ccdik_joint_editor_draw_gizmo(which, p_value);
+		}
+#endif // TOOLS_ENABLED
+
+		return true;
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path.begins_with("editor/draw_gizmo")) {
+		set_editor_draw_gizmo(p_value);
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+bool SkeletonModification2DCCDIK::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path.begins_with("joint_data/")) {
+		int which = path.get_slicec('/', 1).to_int();
+		String what = path.get_slicec('/', 2);
+		ERR_FAIL_INDEX_V(which, ccdik_data_chain.size(), false);
+
+		if (what == "bone2d_node") {
+			r_ret = get_ccdik_joint_bone2d_node(which);
+		} else if (what == "bone_index") {
+			r_ret = get_ccdik_joint_bone_index(which);
+		} else if (what == "rotate_from_joint") {
+			r_ret = get_ccdik_joint_rotate_from_joint(which);
+		} else if (what == "enable_constraint") {
+			r_ret = get_ccdik_joint_enable_constraint(which);
+		} else if (what == "constraint_angle_min") {
+			r_ret = Math::rad2deg(get_ccdik_joint_constraint_angle_min(which));
+		} else if (what == "constraint_angle_max") {
+			r_ret = Math::rad2deg(get_ccdik_joint_constraint_angle_max(which));
+		} else if (what == "constraint_angle_invert") {
+			r_ret = get_ccdik_joint_constraint_angle_invert(which);
+		} else if (what == "constraint_in_localspace") {
+			r_ret = get_ccdik_joint_constraint_in_localspace(which);
+		}
+
+#ifdef TOOLS_ENABLED
+		if (what.begins_with("editor_draw_gizmo")) {
+			r_ret = get_ccdik_joint_editor_draw_gizmo(which);
+		}
+#endif // TOOLS_ENABLED
+
+		return true;
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path.begins_with("editor/draw_gizmo")) {
+		r_ret = get_editor_draw_gizmo();
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+void SkeletonModification2DCCDIK::_get_property_list(List<PropertyInfo> *p_list) const {
+	for (int i = 0; i < ccdik_data_chain.size(); i++) {
+		String base_string = "joint_data/" + itos(i) + "/";
+
+		p_list->push_back(PropertyInfo(Variant::INT, base_string + "bone_index", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::NODE_PATH, base_string + "bone2d_node", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Bone2D", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::BOOL, base_string + "rotate_from_joint", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+
+		p_list->push_back(PropertyInfo(Variant::BOOL, base_string + "enable_constraint", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		if (ccdik_data_chain[i].enable_constraint) {
+			p_list->push_back(PropertyInfo(Variant::FLOAT, base_string + "constraint_angle_min", PROPERTY_HINT_RANGE, "-360, 360, 0.01", PROPERTY_USAGE_DEFAULT));
+			p_list->push_back(PropertyInfo(Variant::FLOAT, base_string + "constraint_angle_max", PROPERTY_HINT_RANGE, "-360, 360, 0.01", PROPERTY_USAGE_DEFAULT));
+			p_list->push_back(PropertyInfo(Variant::BOOL, base_string + "constraint_angle_invert", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+			p_list->push_back(PropertyInfo(Variant::BOOL, base_string + "constraint_in_localspace", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		}
+
+#ifdef TOOLS_ENABLED
+		if (Engine::get_singleton()->is_editor_hint()) {
+			p_list->push_back(PropertyInfo(Variant::BOOL, base_string + "editor_draw_gizmo", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		}
+#endif // TOOLS_ENABLED
+	}
+
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		p_list->push_back(PropertyInfo(Variant::BOOL, "editor/draw_gizmo", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	}
+#endif // TOOLS_ENABLED
+}
+
+void SkeletonModification2DCCDIK::_execute(float p_delta) {
+	ERR_FAIL_COND_MSG(!stack || !is_setup || stack->skeleton == nullptr,
+			"Modification is not setup and therefore cannot execute!");
+	if (!enabled) {
+		return;
+	}
+
+	if (target_node_cache.is_null()) {
+		WARN_PRINT_ONCE("Target cache is out of date. Attempting to update...");
+		update_target_cache();
+		return;
+	}
+	if (tip_node_cache.is_null()) {
+		WARN_PRINT_ONCE("Tip cache is out of date. Attempting to update...");
+		update_tip_cache();
+		return;
+	}
+
+	Node2D *target = Object::cast_to<Node2D>(ObjectDB::get_instance(target_node_cache));
+	if (!target || !target->is_inside_tree()) {
+		ERR_PRINT_ONCE("Target node is not in the scene tree. Cannot execute modification!");
+		return;
+	}
+
+	Node2D *tip = Object::cast_to<Node2D>(ObjectDB::get_instance(tip_node_cache));
+	if (!tip || !tip->is_inside_tree()) {
+		ERR_PRINT_ONCE("Tip node is not in the scene tree. Cannot execute modification!");
+		return;
+	}
+
+	for (int i = 0; i < ccdik_data_chain.size(); i++) {
+		_execute_ccdik_joint(i, target, tip);
+	}
+}
+
+void SkeletonModification2DCCDIK::_execute_ccdik_joint(int p_joint_idx, Node2D *p_target, Node2D *p_tip) {
+	CCDIK_Joint_Data2D ccdik_data = ccdik_data_chain[p_joint_idx];
+	if (ccdik_data.bone_idx < 0 || ccdik_data.bone_idx > stack->skeleton->get_bone_count()) {
+		ERR_PRINT_ONCE("2D CCDIK joint: bone index not found!");
+		return;
+	}
+
+	Bone2D *operation_bone = stack->skeleton->get_bone(ccdik_data.bone_idx);
+	Transform2D operation_transform = operation_bone->get_global_transform();
+
+	if (ccdik_data.rotate_from_joint) {
+		// To rotate from the joint, simply look at the target!
+		operation_transform.set_rotation(
+				operation_transform.looking_at(p_target->get_global_transform().get_origin()).get_rotation() - operation_bone->get_bone_angle());
+	} else {
+		// How to rotate from the tip: get the difference of rotation needed from the tip to the target, from the perspective of the joint.
+		// Because we are only using the offset, we do not need to account for the bone angle of the Bone2D node.
+		float joint_to_tip = operation_transform.get_origin().angle_to_point(p_tip->get_global_transform().get_origin());
+		float joint_to_target = operation_transform.get_origin().angle_to_point(p_target->get_global_transform().get_origin());
+		operation_transform.set_rotation(
+				operation_transform.get_rotation() + (joint_to_target - joint_to_tip));
+	}
+
+	// Reset scale
+	operation_transform.set_scale(operation_bone->get_global_transform().get_scale());
+
+	// Apply constraints in globalspace:
+	if (ccdik_data.enable_constraint && !ccdik_data.constraint_in_localspace) {
+		operation_transform.set_rotation(clamp_angle(operation_transform.get_rotation(), ccdik_data.constraint_angle_min, ccdik_data.constraint_angle_max, ccdik_data.constraint_angle_invert));
+	}
+
+	// Convert from a global transform to a delta and then apply the delta to the local transform.
+	operation_bone->set_global_transform(operation_transform);
+	operation_transform = operation_bone->get_transform();
+
+	// Apply constraints in localspace:
+	if (ccdik_data.enable_constraint && ccdik_data.constraint_in_localspace) {
+		operation_transform.set_rotation(clamp_angle(operation_transform.get_rotation(), ccdik_data.constraint_angle_min, ccdik_data.constraint_angle_max, ccdik_data.constraint_angle_invert));
+	}
+
+	// Set the local pose override, and to make sure child bones are also updated, set the transform of the bone.
+	stack->skeleton->set_bone_local_pose_override(ccdik_data.bone_idx, operation_transform, stack->strength, true);
+	operation_bone->set_transform(operation_transform);
+	operation_bone->notification(operation_bone->NOTIFICATION_TRANSFORM_CHANGED);
+}
+
+void SkeletonModification2DCCDIK::_setup_modification(SkeletonModificationStack2D *p_stack) {
+	stack = p_stack;
+
+	if (stack != nullptr) {
+		is_setup = true;
+		update_target_cache();
+		update_tip_cache();
+	}
+}
+
+void SkeletonModification2DCCDIK::_draw_editor_gizmo() {
+	if (!enabled || !is_setup) {
+		return;
+	}
+
+	for (int i = 0; i < ccdik_data_chain.size(); i++) {
+		if (!ccdik_data_chain[i].editor_draw_gizmo) {
+			continue;
+		}
+
+		Bone2D *operation_bone = stack->skeleton->get_bone(ccdik_data_chain[i].bone_idx);
+		editor_draw_angle_constraints(operation_bone, ccdik_data_chain[i].constraint_angle_min, ccdik_data_chain[i].constraint_angle_max,
+				ccdik_data_chain[i].enable_constraint, ccdik_data_chain[i].constraint_in_localspace, ccdik_data_chain[i].constraint_angle_invert);
+	}
+}
+
+void SkeletonModification2DCCDIK::update_target_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update target cache: modification is not properly setup!");
+		return;
+	}
+
+	target_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(target_node)) {
+				Node *node = stack->skeleton->get_node(target_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update target cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update target cache: node is not in the scene tree!");
+				target_node_cache = node->get_instance_id();
+			}
+		}
+	}
+}
+
+void SkeletonModification2DCCDIK::update_tip_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update tip cache: modification is not properly setup!");
+		return;
+	}
+
+	tip_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(tip_node)) {
+				Node *node = stack->skeleton->get_node(tip_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update tip cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update tip cache: node is not in the scene tree!");
+				tip_node_cache = node->get_instance_id();
+			}
+		}
+	}
+}
+
+void SkeletonModification2DCCDIK::ccdik_joint_update_bone2d_cache(int p_joint_idx) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "Cannot update bone2d cache: joint index out of range!");
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update CCDIK Bone2D cache: modification is not properly setup!");
+		return;
+	}
+
+	ccdik_data_chain.write[p_joint_idx].bone2d_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(ccdik_data_chain[p_joint_idx].bone2d_node)) {
+				Node *node = stack->skeleton->get_node(ccdik_data_chain[p_joint_idx].bone2d_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update CCDIK joint " + itos(p_joint_idx) + " Bone2D cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update CCDIK joint " + itos(p_joint_idx) + " Bone2D cache: node is not in the scene tree!");
+				ccdik_data_chain.write[p_joint_idx].bone2d_node_cache = node->get_instance_id();
+
+				Bone2D *bone = Object::cast_to<Bone2D>(node);
+				if (bone) {
+					ccdik_data_chain.write[p_joint_idx].bone_idx = bone->get_index_in_skeleton();
+				} else {
+					ERR_FAIL_MSG("CCDIK joint " + itos(p_joint_idx) + " Bone2D cache: Nodepath to Bone2D is not a Bone2D node!");
+				}
+			}
+		}
+	}
+}
+
+void SkeletonModification2DCCDIK::set_target_node(const NodePath &p_target_node) {
+	target_node = p_target_node;
+	update_target_cache();
+}
+
+NodePath SkeletonModification2DCCDIK::get_target_node() const {
+	return target_node;
+}
+
+void SkeletonModification2DCCDIK::set_tip_node(const NodePath &p_tip_node) {
+	tip_node = p_tip_node;
+	update_tip_cache();
+}
+
+NodePath SkeletonModification2DCCDIK::get_tip_node() const {
+	return tip_node;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_data_chain_length(int p_length) {
+	ccdik_data_chain.resize(p_length);
+	notify_property_list_changed();
+}
+
+int SkeletonModification2DCCDIK::get_ccdik_data_chain_length() {
+	return ccdik_data_chain.size();
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_bone2d_node(int p_joint_idx, const NodePath &p_target_node) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCDIK joint out of range!");
+	ccdik_data_chain.write[p_joint_idx].bone2d_node = p_target_node;
+	ccdik_joint_update_bone2d_cache(p_joint_idx);
+
+	notify_property_list_changed();
+}
+
+NodePath SkeletonModification2DCCDIK::get_ccdik_joint_bone2d_node(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), NodePath(), "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].bone2d_node;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_bone_index(int p_joint_idx, int p_bone_idx) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCCDIK joint out of range!");
+	ERR_FAIL_COND_MSG(p_bone_idx < 0, "Bone index is out of range: The index is too low!");
+
+	if (is_setup) {
+		if (stack->skeleton) {
+			ERR_FAIL_INDEX_MSG(p_bone_idx, stack->skeleton->get_bone_count(), "Passed-in Bone index is out of range!");
+			ccdik_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+			ccdik_data_chain.write[p_joint_idx].bone2d_node_cache = stack->skeleton->get_bone(p_bone_idx)->get_instance_id();
+			ccdik_data_chain.write[p_joint_idx].bone2d_node = stack->skeleton->get_path_to(stack->skeleton->get_bone(p_bone_idx));
+		} else {
+			WARN_PRINT("Cannot verify the CCDIK joint " + itos(p_joint_idx) + " bone index for this modification...");
+			ccdik_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+		}
+	} else {
+		WARN_PRINT("Cannot verify the CCDIK joint " + itos(p_joint_idx) + " bone index for this modification...");
+		ccdik_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+	}
+
+	notify_property_list_changed();
+}
+
+int SkeletonModification2DCCDIK::get_ccdik_joint_bone_index(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), -1, "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].bone_idx;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_rotate_from_joint(int p_joint_idx, bool p_rotate_from_joint) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCDIK joint out of range!");
+	ccdik_data_chain.write[p_joint_idx].rotate_from_joint = p_rotate_from_joint;
+}
+
+bool SkeletonModification2DCCDIK::get_ccdik_joint_rotate_from_joint(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), false, "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].rotate_from_joint;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_enable_constraint(int p_joint_idx, bool p_constraint) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCDIK joint out of range!");
+	ccdik_data_chain.write[p_joint_idx].enable_constraint = p_constraint;
+	notify_property_list_changed();
+
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2DCCDIK::get_ccdik_joint_enable_constraint(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), false, "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].enable_constraint;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_constraint_angle_min(int p_joint_idx, float p_angle_min) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCDIK joint out of range!");
+	ccdik_data_chain.write[p_joint_idx].constraint_angle_min = p_angle_min;
+
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+float SkeletonModification2DCCDIK::get_ccdik_joint_constraint_angle_min(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), 0.0, "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].constraint_angle_min;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_constraint_angle_max(int p_joint_idx, float p_angle_max) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCDIK joint out of range!");
+	ccdik_data_chain.write[p_joint_idx].constraint_angle_max = p_angle_max;
+
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+float SkeletonModification2DCCDIK::get_ccdik_joint_constraint_angle_max(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), 0.0, "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].constraint_angle_max;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_constraint_angle_invert(int p_joint_idx, bool p_invert) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCDIK joint out of range!");
+	ccdik_data_chain.write[p_joint_idx].constraint_angle_invert = p_invert;
+
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2DCCDIK::get_ccdik_joint_constraint_angle_invert(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), false, "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].constraint_angle_invert;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_constraint_in_localspace(int p_joint_idx, bool p_constraint_in_localspace) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCDIK joint out of range!");
+	ccdik_data_chain.write[p_joint_idx].constraint_in_localspace = p_constraint_in_localspace;
+
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2DCCDIK::get_ccdik_joint_constraint_in_localspace(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), false, "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].constraint_in_localspace;
+}
+
+void SkeletonModification2DCCDIK::set_ccdik_joint_editor_draw_gizmo(int p_joint_idx, bool p_draw_gizmo) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, ccdik_data_chain.size(), "CCDIK joint out of range!");
+	ccdik_data_chain.write[p_joint_idx].editor_draw_gizmo = p_draw_gizmo;
+
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2DCCDIK::get_ccdik_joint_editor_draw_gizmo(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, ccdik_data_chain.size(), false, "CCDIK joint out of range!");
+	return ccdik_data_chain[p_joint_idx].editor_draw_gizmo;
+}
+
+void SkeletonModification2DCCDIK::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_target_node", "target_nodepath"), &SkeletonModification2DCCDIK::set_target_node);
+	ClassDB::bind_method(D_METHOD("get_target_node"), &SkeletonModification2DCCDIK::get_target_node);
+	ClassDB::bind_method(D_METHOD("set_tip_node", "tip_nodepath"), &SkeletonModification2DCCDIK::set_tip_node);
+	ClassDB::bind_method(D_METHOD("get_tip_node"), &SkeletonModification2DCCDIK::get_tip_node);
+
+	ClassDB::bind_method(D_METHOD("set_ccdik_data_chain_length", "length"), &SkeletonModification2DCCDIK::set_ccdik_data_chain_length);
+	ClassDB::bind_method(D_METHOD("get_ccdik_data_chain_length"), &SkeletonModification2DCCDIK::get_ccdik_data_chain_length);
+
+	ClassDB::bind_method(D_METHOD("set_ccdik_joint_bone2d_node", "joint_idx", "bone2d_nodepath"), &SkeletonModification2DCCDIK::set_ccdik_joint_bone2d_node);
+	ClassDB::bind_method(D_METHOD("get_ccdik_joint_bone2d_node", "joint_idx"), &SkeletonModification2DCCDIK::get_ccdik_joint_bone2d_node);
+	ClassDB::bind_method(D_METHOD("set_ccdik_joint_bone_index", "joint_idx", "bone_idx"), &SkeletonModification2DCCDIK::set_ccdik_joint_bone_index);
+	ClassDB::bind_method(D_METHOD("get_ccdik_joint_bone_index", "joint_idx"), &SkeletonModification2DCCDIK::get_ccdik_joint_bone_index);
+	ClassDB::bind_method(D_METHOD("set_ccdik_joint_rotate_from_joint", "joint_idx", "rotate_from_joint"), &SkeletonModification2DCCDIK::set_ccdik_joint_rotate_from_joint);
+	ClassDB::bind_method(D_METHOD("get_ccdik_joint_rotate_from_joint", "joint_idx"), &SkeletonModification2DCCDIK::get_ccdik_joint_rotate_from_joint);
+	ClassDB::bind_method(D_METHOD("set_ccdik_joint_enable_constraint", "joint_idx", "enable_constraint"), &SkeletonModification2DCCDIK::set_ccdik_joint_enable_constraint);
+	ClassDB::bind_method(D_METHOD("get_ccdik_joint_enable_constraint", "joint_idx"), &SkeletonModification2DCCDIK::get_ccdik_joint_enable_constraint);
+	ClassDB::bind_method(D_METHOD("set_ccdik_joint_constraint_angle_min", "joint_idx", "angle_min"), &SkeletonModification2DCCDIK::set_ccdik_joint_constraint_angle_min);
+	ClassDB::bind_method(D_METHOD("get_ccdik_joint_constraint_angle_min", "joint_idx"), &SkeletonModification2DCCDIK::get_ccdik_joint_constraint_angle_min);
+	ClassDB::bind_method(D_METHOD("set_ccdik_joint_constraint_angle_max", "joint_idx", "angle_max"), &SkeletonModification2DCCDIK::set_ccdik_joint_constraint_angle_max);
+	ClassDB::bind_method(D_METHOD("get_ccdik_joint_constraint_angle_max", "joint_idx"), &SkeletonModification2DCCDIK::get_ccdik_joint_constraint_angle_max);
+	ClassDB::bind_method(D_METHOD("set_ccdik_joint_constraint_angle_invert", "joint_idx", "invert"), &SkeletonModification2DCCDIK::set_ccdik_joint_constraint_angle_invert);
+	ClassDB::bind_method(D_METHOD("get_ccdik_joint_constraint_angle_invert", "joint_idx"), &SkeletonModification2DCCDIK::get_ccdik_joint_constraint_angle_invert);
+
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "target_nodepath", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Node2D"), "set_target_node", "get_target_node");
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "tip_nodepath", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Node2D"), "set_tip_node", "get_tip_node");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "ccdik_data_chain_length", PROPERTY_HINT_RANGE, "0, 100, 1"), "set_ccdik_data_chain_length", "get_ccdik_data_chain_length");
+}
+
+SkeletonModification2DCCDIK::SkeletonModification2DCCDIK() {
+	stack = nullptr;
+	is_setup = false;
+	enabled = true;
+	editor_draw_gizmo = true;
+}
+
+SkeletonModification2DCCDIK::~SkeletonModification2DCCDIK() {
+}
diff --git a/scene/resources/skeleton_modification_2d_ccdik.h b/scene/resources/skeleton_modification_2d_ccdik.h
new file mode 100644
index 0000000000..dc48291f62
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_ccdik.h
@@ -0,0 +1,116 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_ccdik.h                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATION2DCCDIK_H
+#define SKELETONMODIFICATION2DCCDIK_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+
+///////////////////////////////////////
+// SkeletonModification2DCCDIK
+///////////////////////////////////////
+
+class SkeletonModification2DCCDIK : public SkeletonModification2D {
+	GDCLASS(SkeletonModification2DCCDIK, SkeletonModification2D);
+
+private:
+	struct CCDIK_Joint_Data2D {
+		int bone_idx = -1;
+		NodePath bone2d_node;
+		ObjectID bone2d_node_cache;
+		bool rotate_from_joint = false;
+
+		bool enable_constraint = false;
+		float constraint_angle_min = 0;
+		float constraint_angle_max = (2.0 * Math_PI);
+		bool constraint_angle_invert = false;
+		bool constraint_in_localspace = true;
+
+		bool editor_draw_gizmo = true;
+	};
+
+	Vector<CCDIK_Joint_Data2D> ccdik_data_chain;
+
+	NodePath target_node;
+	ObjectID target_node_cache;
+	void update_target_cache();
+
+	NodePath tip_node;
+	ObjectID tip_node_cache;
+	void update_tip_cache();
+
+	void ccdik_joint_update_bone2d_cache(int p_joint_idx);
+	void _execute_ccdik_joint(int p_joint_idx, Node2D *p_target, Node2D *p_tip);
+
+protected:
+	static void _bind_methods();
+	bool _set(const StringName &p_path, const Variant &p_value);
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+
+public:
+	void _execute(float p_delta) override;
+	void _setup_modification(SkeletonModificationStack2D *p_stack) override;
+	void _draw_editor_gizmo() override;
+
+	void set_target_node(const NodePath &p_target_node);
+	NodePath get_target_node() const;
+	void set_tip_node(const NodePath &p_tip_node);
+	NodePath get_tip_node() const;
+
+	int get_ccdik_data_chain_length();
+	void set_ccdik_data_chain_length(int p_new_length);
+
+	void set_ccdik_joint_bone2d_node(int p_joint_idx, const NodePath &p_target_node);
+	NodePath get_ccdik_joint_bone2d_node(int p_joint_idx) const;
+	void set_ccdik_joint_bone_index(int p_joint_idx, int p_bone_idx);
+	int get_ccdik_joint_bone_index(int p_joint_idx) const;
+
+	void set_ccdik_joint_rotate_from_joint(int p_joint_idx, bool p_rotate_from_joint);
+	bool get_ccdik_joint_rotate_from_joint(int p_joint_idx) const;
+	void set_ccdik_joint_enable_constraint(int p_joint_idx, bool p_constraint);
+	bool get_ccdik_joint_enable_constraint(int p_joint_idx) const;
+	void set_ccdik_joint_constraint_angle_min(int p_joint_idx, float p_angle_min);
+	float get_ccdik_joint_constraint_angle_min(int p_joint_idx) const;
+	void set_ccdik_joint_constraint_angle_max(int p_joint_idx, float p_angle_max);
+	float get_ccdik_joint_constraint_angle_max(int p_joint_idx) const;
+	void set_ccdik_joint_constraint_angle_invert(int p_joint_idx, bool p_invert);
+	bool get_ccdik_joint_constraint_angle_invert(int p_joint_idx) const;
+	void set_ccdik_joint_constraint_in_localspace(int p_joint_idx, bool p_constraint_in_localspace);
+	bool get_ccdik_joint_constraint_in_localspace(int p_joint_idx) const;
+	void set_ccdik_joint_editor_draw_gizmo(int p_joint_idx, bool p_draw_gizmo);
+	bool get_ccdik_joint_editor_draw_gizmo(int p_joint_idx) const;
+
+	SkeletonModification2DCCDIK();
+	~SkeletonModification2DCCDIK();
+};
+
+#endif // SKELETONMODIFICATION2DCCDIK_H
diff --git a/scene/resources/skeleton_modification_2d_fabrik.cpp b/scene/resources/skeleton_modification_2d_fabrik.cpp
new file mode 100644
index 0000000000..aef852f7e4
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_fabrik.cpp
@@ -0,0 +1,444 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_fabrik.cpp                                  */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_2d_fabrik.h"
+#include "scene/2d/skeleton_2d.h"
+
+#ifdef TOOLS_ENABLED
+#include "editor/editor_settings.h"
+#endif // TOOLS_ENABLED
+
+bool SkeletonModification2DFABRIK::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path.begins_with("joint_data/")) {
+		int which = path.get_slicec('/', 1).to_int();
+		String what = path.get_slicec('/', 2);
+		ERR_FAIL_INDEX_V(which, fabrik_data_chain.size(), false);
+
+		if (what == "bone2d_node") {
+			set_fabrik_joint_bone2d_node(which, p_value);
+		} else if (what == "bone_index") {
+			set_fabrik_joint_bone_index(which, p_value);
+		} else if (what == "magnet_position") {
+			set_fabrik_joint_magnet_position(which, p_value);
+		} else if (what == "use_target_rotation") {
+			set_fabrik_joint_use_target_rotation(which, p_value);
+		}
+	}
+
+	return true;
+}
+
+bool SkeletonModification2DFABRIK::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path.begins_with("joint_data/")) {
+		int which = path.get_slicec('/', 1).to_int();
+		String what = path.get_slicec('/', 2);
+		ERR_FAIL_INDEX_V(which, fabrik_data_chain.size(), false);
+
+		if (what == "bone2d_node") {
+			r_ret = get_fabrik_joint_bone2d_node(which);
+		} else if (what == "bone_index") {
+			r_ret = get_fabrik_joint_bone_index(which);
+		} else if (what == "magnet_position") {
+			r_ret = get_fabrik_joint_magnet_position(which);
+		} else if (what == "use_target_rotation") {
+			r_ret = get_fabrik_joint_use_target_rotation(which);
+		}
+		return true;
+	}
+	return true;
+}
+
+void SkeletonModification2DFABRIK::_get_property_list(List<PropertyInfo> *p_list) const {
+	for (int i = 0; i < fabrik_data_chain.size(); i++) {
+		String base_string = "joint_data/" + itos(i) + "/";
+
+		p_list->push_back(PropertyInfo(Variant::INT, base_string + "bone_index", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::NODE_PATH, base_string + "bone2d_node", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Bone2D", PROPERTY_USAGE_DEFAULT));
+
+		if (i > 0) {
+			p_list->push_back(PropertyInfo(Variant::VECTOR2, base_string + "magnet_position", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		}
+		if (i == fabrik_data_chain.size() - 1) {
+			p_list->push_back(PropertyInfo(Variant::BOOL, base_string + "use_target_rotation", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		}
+	}
+}
+
+void SkeletonModification2DFABRIK::_execute(float p_delta) {
+	ERR_FAIL_COND_MSG(!stack || !is_setup || stack->skeleton == nullptr,
+			"Modification is not setup and therefore cannot execute!");
+	if (!enabled) {
+		return;
+	}
+
+	if (target_node_cache.is_null()) {
+		WARN_PRINT_ONCE("Target cache is out of date. Attempting to update...");
+		update_target_cache();
+		return;
+	}
+
+	if (fabrik_data_chain.size() <= 1) {
+		ERR_PRINT_ONCE("FABRIK requires at least two joints to operate! Cannot execute modification!");
+		return;
+	}
+
+	Node2D *target = Object::cast_to<Node2D>(ObjectDB::get_instance(target_node_cache));
+	if (!target || !target->is_inside_tree()) {
+		ERR_PRINT_ONCE("Target node is not in the scene tree. Cannot execute modification!");
+		return;
+	}
+	target_global_pose = target->get_global_transform();
+
+	if (fabrik_data_chain[0].bone2d_node_cache.is_null() && !fabrik_data_chain[0].bone2d_node.is_empty()) {
+		fabrik_joint_update_bone2d_cache(0);
+		WARN_PRINT("Bone2D cache for origin joint is out of date. Updating...");
+	}
+
+	Bone2D *origin_bone2d_node = Object::cast_to<Bone2D>(ObjectDB::get_instance(fabrik_data_chain[0].bone2d_node_cache));
+	if (!origin_bone2d_node || !origin_bone2d_node->is_inside_tree()) {
+		ERR_PRINT_ONCE("Origin joint's Bone2D node is not in the scene tree. Cannot execute modification!");
+		return;
+	}
+
+	origin_global_pose = origin_bone2d_node->get_global_transform();
+
+	if (fabrik_transform_chain.size() != fabrik_data_chain.size()) {
+		fabrik_transform_chain.resize(fabrik_data_chain.size());
+	}
+
+	for (int i = 0; i < fabrik_data_chain.size(); i++) {
+		// Update the transform chain
+		if (fabrik_data_chain[i].bone2d_node_cache.is_null() && !fabrik_data_chain[i].bone2d_node.is_empty()) {
+			WARN_PRINT_ONCE("Bone2D cache for joint " + itos(i) + " is out of date.. Attempting to update...");
+			fabrik_joint_update_bone2d_cache(i);
+		}
+		Bone2D *joint_bone2d_node = Object::cast_to<Bone2D>(ObjectDB::get_instance(fabrik_data_chain[i].bone2d_node_cache));
+		if (!joint_bone2d_node) {
+			ERR_PRINT_ONCE("FABRIK Joint " + itos(i) + " does not have a Bone2D node set! Cannot execute modification!");
+			return;
+		}
+		fabrik_transform_chain.write[i] = joint_bone2d_node->get_global_transform();
+
+		// Apply magnet positions
+		if (i == 0) {
+			continue; // The origin cannot use a magnet position!
+		} else {
+			Transform2D joint_trans = fabrik_transform_chain[i];
+			joint_trans.set_origin(joint_trans.get_origin() + fabrik_data_chain[i].magnet_position);
+			fabrik_transform_chain.write[i] = joint_trans;
+		}
+	}
+
+	Bone2D *final_bone2d_node = Object::cast_to<Bone2D>(ObjectDB::get_instance(fabrik_data_chain[fabrik_data_chain.size() - 1].bone2d_node_cache));
+	float final_bone2d_angle = final_bone2d_node->get_global_transform().get_rotation();
+	if (fabrik_data_chain[fabrik_data_chain.size() - 1].use_target_rotation) {
+		final_bone2d_angle = target_global_pose.get_rotation();
+	}
+	Vector2 final_bone2d_direction = Vector2(Math::cos(final_bone2d_angle), Math::sin(final_bone2d_angle));
+	float final_bone2d_length = final_bone2d_node->get_length() * MIN(final_bone2d_node->get_global_scale().x, final_bone2d_node->get_global_scale().y);
+	float target_distance = (final_bone2d_node->get_global_transform().get_origin() + (final_bone2d_direction * final_bone2d_length)).distance_to(target->get_global_transform().get_origin());
+	chain_iterations = 0;
+
+	while (target_distance > chain_tolarance) {
+		chain_backwards();
+		chain_forwards();
+
+		final_bone2d_angle = final_bone2d_node->get_global_transform().get_rotation();
+		if (fabrik_data_chain[fabrik_data_chain.size() - 1].use_target_rotation) {
+			final_bone2d_angle = target_global_pose.get_rotation();
+		}
+		final_bone2d_direction = Vector2(Math::cos(final_bone2d_angle), Math::sin(final_bone2d_angle));
+		target_distance = (final_bone2d_node->get_global_transform().get_origin() + (final_bone2d_direction * final_bone2d_length)).distance_to(target->get_global_transform().get_origin());
+
+		chain_iterations += 1;
+		if (chain_iterations >= chain_max_iterations) {
+			break;
+		}
+	}
+
+	// Apply all of the saved transforms to the Bone2D nodes
+	for (int i = 0; i < fabrik_data_chain.size(); i++) {
+		Bone2D *joint_bone2d_node = Object::cast_to<Bone2D>(ObjectDB::get_instance(fabrik_data_chain[i].bone2d_node_cache));
+		if (!joint_bone2d_node) {
+			ERR_PRINT_ONCE("FABRIK Joint " + itos(i) + " does not have a Bone2D node set!");
+			continue;
+		}
+		Transform2D chain_trans = fabrik_transform_chain[i];
+
+		// Apply rotation
+		if (i + 1 < fabrik_data_chain.size()) {
+			chain_trans = chain_trans.looking_at(fabrik_transform_chain[i + 1].get_origin());
+		} else {
+			if (fabrik_data_chain[i].use_target_rotation) {
+				chain_trans.set_rotation(target_global_pose.get_rotation());
+			} else {
+				chain_trans = chain_trans.looking_at(target_global_pose.get_origin());
+			}
+		}
+		// Adjust for the bone angle
+		chain_trans.set_rotation(chain_trans.get_rotation() - joint_bone2d_node->get_bone_angle());
+
+		// Reset scale
+		chain_trans.set_scale(joint_bone2d_node->get_global_transform().get_scale());
+
+		// Apply to the bone, and to the override
+		joint_bone2d_node->set_global_transform(chain_trans);
+		stack->skeleton->set_bone_local_pose_override(fabrik_data_chain[i].bone_idx, joint_bone2d_node->get_transform(), stack->strength, true);
+	}
+}
+
+void SkeletonModification2DFABRIK::chain_backwards() {
+	int final_joint_index = fabrik_data_chain.size() - 1;
+	Bone2D *final_bone2d_node = Object::cast_to<Bone2D>(ObjectDB::get_instance(fabrik_data_chain[final_joint_index].bone2d_node_cache));
+	Transform2D final_bone2d_trans = fabrik_transform_chain[final_joint_index];
+
+	// Set the rotation of the tip bone
+	final_bone2d_trans = final_bone2d_trans.looking_at(target_global_pose.get_origin());
+
+	// Set the position of the tip bone
+	float final_bone2d_angle = final_bone2d_trans.get_rotation();
+	if (fabrik_data_chain[final_joint_index].use_target_rotation) {
+		final_bone2d_angle = target_global_pose.get_rotation();
+	}
+	Vector2 final_bone2d_direction = Vector2(Math::cos(final_bone2d_angle), Math::sin(final_bone2d_angle));
+	float final_bone2d_length = final_bone2d_node->get_length() * MIN(final_bone2d_node->get_global_scale().x, final_bone2d_node->get_global_scale().y);
+	final_bone2d_trans.set_origin(target_global_pose.get_origin() - (final_bone2d_direction * final_bone2d_length));
+
+	// Save the transform
+	fabrik_transform_chain.write[final_joint_index] = final_bone2d_trans;
+
+	int i = final_joint_index;
+	while (i >= 1) {
+		Transform2D previous_pose = fabrik_transform_chain[i];
+		i -= 1;
+		Bone2D *current_bone2d_node = Object::cast_to<Bone2D>(ObjectDB::get_instance(fabrik_data_chain[i].bone2d_node_cache));
+		Transform2D current_pose = fabrik_transform_chain[i];
+
+		float current_bone2d_node_length = current_bone2d_node->get_length() * MIN(current_bone2d_node->get_global_scale().x, current_bone2d_node->get_global_scale().y);
+		float length = current_bone2d_node_length / (previous_pose.get_origin() - current_pose.get_origin()).length();
+		Vector2 finish_position = previous_pose.get_origin().lerp(current_pose.get_origin(), length);
+		current_pose.set_origin(finish_position);
+
+		// Save the transform
+		fabrik_transform_chain.write[i] = current_pose;
+	}
+}
+
+void SkeletonModification2DFABRIK::chain_forwards() {
+	Transform2D origin_bone2d_trans = fabrik_transform_chain[0];
+	origin_bone2d_trans.set_origin(origin_global_pose.get_origin());
+	// Save the position
+	fabrik_transform_chain.write[0] = origin_bone2d_trans;
+
+	for (int i = 0; i < fabrik_data_chain.size() - 1; i++) {
+		Bone2D *current_bone2d_node = Object::cast_to<Bone2D>(ObjectDB::get_instance(fabrik_data_chain[i].bone2d_node_cache));
+		Transform2D current_pose = fabrik_transform_chain[i];
+		Transform2D next_pose = fabrik_transform_chain[i + 1];
+
+		float current_bone2d_node_length = current_bone2d_node->get_length() * MIN(current_bone2d_node->get_global_scale().x, current_bone2d_node->get_global_scale().y);
+		float length = current_bone2d_node_length / (current_pose.get_origin() - next_pose.get_origin()).length();
+		Vector2 finish_position = current_pose.get_origin().lerp(next_pose.get_origin(), length);
+		current_pose.set_origin(finish_position);
+
+		// Apply to the bone
+		fabrik_transform_chain.write[i + 1] = current_pose;
+	}
+}
+
+void SkeletonModification2DFABRIK::_setup_modification(SkeletonModificationStack2D *p_stack) {
+	stack = p_stack;
+
+	if (stack != nullptr) {
+		is_setup = true;
+		update_target_cache();
+	}
+}
+
+void SkeletonModification2DFABRIK::update_target_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update target cache: modification is not properly setup!");
+		return;
+	}
+
+	target_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(target_node)) {
+				Node *node = stack->skeleton->get_node(target_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update target cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update target cache: node is not in scene tree!");
+				target_node_cache = node->get_instance_id();
+			}
+		}
+	}
+}
+
+void SkeletonModification2DFABRIK::fabrik_joint_update_bone2d_cache(int p_joint_idx) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, fabrik_data_chain.size(), "Cannot update bone2d cache: joint index out of range!");
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update FABRIK Bone2D cache: modification is not properly setup!");
+		return;
+	}
+
+	fabrik_data_chain.write[p_joint_idx].bone2d_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(fabrik_data_chain[p_joint_idx].bone2d_node)) {
+				Node *node = stack->skeleton->get_node(fabrik_data_chain[p_joint_idx].bone2d_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update FABRIK joint " + itos(p_joint_idx) + " Bone2D cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update FABRIK joint " + itos(p_joint_idx) + " Bone2D cache: node is not in scene tree!");
+				fabrik_data_chain.write[p_joint_idx].bone2d_node_cache = node->get_instance_id();
+
+				Bone2D *bone = Object::cast_to<Bone2D>(node);
+				if (bone) {
+					fabrik_data_chain.write[p_joint_idx].bone_idx = bone->get_index_in_skeleton();
+				} else {
+					ERR_FAIL_MSG("FABRIK joint " + itos(p_joint_idx) + " Bone2D cache: Nodepath to Bone2D is not a Bone2D node!");
+				}
+			}
+		}
+	}
+}
+
+void SkeletonModification2DFABRIK::set_target_node(const NodePath &p_target_node) {
+	target_node = p_target_node;
+	update_target_cache();
+}
+
+NodePath SkeletonModification2DFABRIK::get_target_node() const {
+	return target_node;
+}
+
+void SkeletonModification2DFABRIK::set_fabrik_data_chain_length(int p_length) {
+	fabrik_data_chain.resize(p_length);
+	notify_property_list_changed();
+}
+
+int SkeletonModification2DFABRIK::get_fabrik_data_chain_length() {
+	return fabrik_data_chain.size();
+}
+
+void SkeletonModification2DFABRIK::set_fabrik_joint_bone2d_node(int p_joint_idx, const NodePath &p_target_node) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, fabrik_data_chain.size(), "FABRIK joint out of range!");
+	fabrik_data_chain.write[p_joint_idx].bone2d_node = p_target_node;
+	fabrik_joint_update_bone2d_cache(p_joint_idx);
+
+	notify_property_list_changed();
+}
+
+NodePath SkeletonModification2DFABRIK::get_fabrik_joint_bone2d_node(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, fabrik_data_chain.size(), NodePath(), "FABRIK joint out of range!");
+	return fabrik_data_chain[p_joint_idx].bone2d_node;
+}
+
+void SkeletonModification2DFABRIK::set_fabrik_joint_bone_index(int p_joint_idx, int p_bone_idx) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, fabrik_data_chain.size(), "FABRIK joint out of range!");
+	ERR_FAIL_COND_MSG(p_bone_idx < 0, "Bone index is out of range: The index is too low!");
+
+	if (is_setup) {
+		if (stack->skeleton) {
+			ERR_FAIL_INDEX_MSG(p_bone_idx, stack->skeleton->get_bone_count(), "Passed-in Bone index is out of range!");
+			fabrik_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+			fabrik_data_chain.write[p_joint_idx].bone2d_node_cache = stack->skeleton->get_bone(p_bone_idx)->get_instance_id();
+			fabrik_data_chain.write[p_joint_idx].bone2d_node = stack->skeleton->get_path_to(stack->skeleton->get_bone(p_bone_idx));
+		} else {
+			WARN_PRINT("Cannot verify the FABRIK joint " + itos(p_joint_idx) + " bone index for this modification...");
+			fabrik_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+		}
+	} else {
+		WARN_PRINT("Cannot verify the FABRIK joint " + itos(p_joint_idx) + " bone index for this modification...");
+		fabrik_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+	}
+
+	notify_property_list_changed();
+}
+
+int SkeletonModification2DFABRIK::get_fabrik_joint_bone_index(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, fabrik_data_chain.size(), -1, "FABRIK joint out of range!");
+	return fabrik_data_chain[p_joint_idx].bone_idx;
+}
+
+void SkeletonModification2DFABRIK::set_fabrik_joint_magnet_position(int p_joint_idx, Vector2 p_magnet_position) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, fabrik_data_chain.size(), "FABRIK joint out of range!");
+	fabrik_data_chain.write[p_joint_idx].magnet_position = p_magnet_position;
+}
+
+Vector2 SkeletonModification2DFABRIK::get_fabrik_joint_magnet_position(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, fabrik_data_chain.size(), Vector2(), "FABRIK joint out of range!");
+	return fabrik_data_chain[p_joint_idx].magnet_position;
+}
+
+void SkeletonModification2DFABRIK::set_fabrik_joint_use_target_rotation(int p_joint_idx, bool p_use_target_rotation) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, fabrik_data_chain.size(), "FABRIK joint out of range!");
+	fabrik_data_chain.write[p_joint_idx].use_target_rotation = p_use_target_rotation;
+}
+
+bool SkeletonModification2DFABRIK::get_fabrik_joint_use_target_rotation(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, fabrik_data_chain.size(), false, "FABRIK joint out of range!");
+	return fabrik_data_chain[p_joint_idx].use_target_rotation;
+}
+
+void SkeletonModification2DFABRIK::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_target_node", "target_nodepath"), &SkeletonModification2DFABRIK::set_target_node);
+	ClassDB::bind_method(D_METHOD("get_target_node"), &SkeletonModification2DFABRIK::get_target_node);
+
+	ClassDB::bind_method(D_METHOD("set_fabrik_data_chain_length", "length"), &SkeletonModification2DFABRIK::set_fabrik_data_chain_length);
+	ClassDB::bind_method(D_METHOD("get_fabrik_data_chain_length"), &SkeletonModification2DFABRIK::get_fabrik_data_chain_length);
+
+	ClassDB::bind_method(D_METHOD("set_fabrik_joint_bone2d_node", "joint_idx", "bone2d_nodepath"), &SkeletonModification2DFABRIK::set_fabrik_joint_bone2d_node);
+	ClassDB::bind_method(D_METHOD("get_fabrik_joint_bone2d_node", "joint_idx"), &SkeletonModification2DFABRIK::get_fabrik_joint_bone2d_node);
+	ClassDB::bind_method(D_METHOD("set_fabrik_joint_bone_index", "joint_idx", "bone_idx"), &SkeletonModification2DFABRIK::set_fabrik_joint_bone_index);
+	ClassDB::bind_method(D_METHOD("get_fabrik_joint_bone_index", "joint_idx"), &SkeletonModification2DFABRIK::get_fabrik_joint_bone_index);
+	ClassDB::bind_method(D_METHOD("set_fabrik_joint_magnet_position", "joint_idx", "magnet_position"), &SkeletonModification2DFABRIK::set_fabrik_joint_magnet_position);
+	ClassDB::bind_method(D_METHOD("get_fabrik_joint_magnet_position", "joint_idx"), &SkeletonModification2DFABRIK::get_fabrik_joint_magnet_position);
+	ClassDB::bind_method(D_METHOD("set_fabrik_joint_use_target_rotation", "joint_idx", "use_target_rotation"), &SkeletonModification2DFABRIK::set_fabrik_joint_use_target_rotation);
+	ClassDB::bind_method(D_METHOD("get_fabrik_joint_use_target_rotation", "joint_idx"), &SkeletonModification2DFABRIK::get_fabrik_joint_use_target_rotation);
+
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "target_nodepath", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Node2D"), "set_target_node", "get_target_node");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "fabrik_data_chain_length", PROPERTY_HINT_RANGE, "0, 100, 1"), "set_fabrik_data_chain_length", "get_fabrik_data_chain_length");
+}
+
+SkeletonModification2DFABRIK::SkeletonModification2DFABRIK() {
+	stack = nullptr;
+	is_setup = false;
+	enabled = true;
+	editor_draw_gizmo = false;
+}
+
+SkeletonModification2DFABRIK::~SkeletonModification2DFABRIK() {
+}
diff --git a/scene/resources/skeleton_modification_2d_fabrik.h b/scene/resources/skeleton_modification_2d_fabrik.h
new file mode 100644
index 0000000000..79e0106e26
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_fabrik.h
@@ -0,0 +1,108 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_fabrik.h                                    */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATION2DFABRIK_H
+#define SKELETONMODIFICATION2DFABRIK_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+
+///////////////////////////////////////
+// SkeletonModification2DFABRIK
+///////////////////////////////////////
+
+class SkeletonModification2DFABRIK : public SkeletonModification2D {
+	GDCLASS(SkeletonModification2DFABRIK, SkeletonModification2D);
+
+private:
+	struct FABRIK_Joint_Data2D {
+		int bone_idx = -1;
+		NodePath bone2d_node;
+		ObjectID bone2d_node_cache;
+
+		Vector2 magnet_position = Vector2(0, 0);
+		bool use_target_rotation = false;
+
+		bool editor_draw_gizmo = true;
+	};
+
+	Vector<FABRIK_Joint_Data2D> fabrik_data_chain;
+
+	// Unlike in 3D, we need a vector of Transform2D objects to perform FABRIK.
+	// This is because FABRIK (unlike CCDIK) needs to operate on transforms that are NOT
+	// affected by each other, making the transforms stored in Bone2D unusable, as well as those in Skeleton2D.
+	// For this reason, this modification stores a vector of Transform2Ds used for the calculations, which are then applied at the end.
+	Vector<Transform2D> fabrik_transform_chain;
+
+	NodePath target_node;
+	ObjectID target_node_cache;
+	void update_target_cache();
+
+	float chain_tolarance = 0.01;
+	int chain_max_iterations = 10;
+	int chain_iterations = 0;
+	Transform2D target_global_pose = Transform2D();
+	Transform2D origin_global_pose = Transform2D();
+
+	void fabrik_joint_update_bone2d_cache(int p_joint_idx);
+	void chain_backwards();
+	void chain_forwards();
+
+protected:
+	static void _bind_methods();
+	bool _set(const StringName &p_path, const Variant &p_value);
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+
+public:
+	void _execute(float p_delta) override;
+	void _setup_modification(SkeletonModificationStack2D *p_stack) override;
+
+	void set_target_node(const NodePath &p_target_node);
+	NodePath get_target_node() const;
+
+	int get_fabrik_data_chain_length();
+	void set_fabrik_data_chain_length(int p_new_length);
+
+	void set_fabrik_joint_bone2d_node(int p_joint_idx, const NodePath &p_target_node);
+	NodePath get_fabrik_joint_bone2d_node(int p_joint_idx) const;
+	void set_fabrik_joint_bone_index(int p_joint_idx, int p_bone_idx);
+	int get_fabrik_joint_bone_index(int p_joint_idx) const;
+
+	void set_fabrik_joint_magnet_position(int p_joint_idx, Vector2 p_magnet_position);
+	Vector2 get_fabrik_joint_magnet_position(int p_joint_idx) const;
+	void set_fabrik_joint_use_target_rotation(int p_joint_idx, bool p_use_target_rotation);
+	bool get_fabrik_joint_use_target_rotation(int p_joint_idx) const;
+
+	SkeletonModification2DFABRIK();
+	~SkeletonModification2DFABRIK();
+};
+
+#endif // SKELETONMODIFICATION2DFABRIK_H
diff --git a/scene/resources/skeleton_modification_2d_jiggle.cpp b/scene/resources/skeleton_modification_2d_jiggle.cpp
new file mode 100644
index 0000000000..2547083336
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_jiggle.cpp
@@ -0,0 +1,564 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_jiggle.cpp                                  */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_2d_jiggle.h"
+#include "scene/2d/skeleton_2d.h"
+
+bool SkeletonModification2DJiggle::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path.begins_with("joint_data/")) {
+		int which = path.get_slicec('/', 1).to_int();
+		String what = path.get_slicec('/', 2);
+		ERR_FAIL_INDEX_V(which, jiggle_data_chain.size(), false);
+
+		if (what == "bone2d_node") {
+			set_jiggle_joint_bone2d_node(which, p_value);
+		} else if (what == "bone_index") {
+			set_jiggle_joint_bone_index(which, p_value);
+		} else if (what == "override_defaults") {
+			set_jiggle_joint_override(which, p_value);
+		} else if (what == "stiffness") {
+			set_jiggle_joint_stiffness(which, p_value);
+		} else if (what == "mass") {
+			set_jiggle_joint_mass(which, p_value);
+		} else if (what == "damping") {
+			set_jiggle_joint_damping(which, p_value);
+		} else if (what == "use_gravity") {
+			set_jiggle_joint_use_gravity(which, p_value);
+		} else if (what == "gravity") {
+			set_jiggle_joint_gravity(which, p_value);
+		}
+		return true;
+	} else {
+		if (path == "use_colliders") {
+			set_use_colliders(p_value);
+		} else if (path == "collision_mask") {
+			set_collision_mask(p_value);
+		}
+	}
+	return true;
+}
+
+bool SkeletonModification2DJiggle::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path.begins_with("joint_data/")) {
+		int which = path.get_slicec('/', 1).to_int();
+		String what = path.get_slicec('/', 2);
+		ERR_FAIL_INDEX_V(which, jiggle_data_chain.size(), false);
+
+		if (what == "bone2d_node") {
+			r_ret = get_jiggle_joint_bone2d_node(which);
+		} else if (what == "bone_index") {
+			r_ret = get_jiggle_joint_bone_index(which);
+		} else if (what == "override_defaults") {
+			r_ret = get_jiggle_joint_override(which);
+		} else if (what == "stiffness") {
+			r_ret = get_jiggle_joint_stiffness(which);
+		} else if (what == "mass") {
+			r_ret = get_jiggle_joint_mass(which);
+		} else if (what == "damping") {
+			r_ret = get_jiggle_joint_damping(which);
+		} else if (what == "use_gravity") {
+			r_ret = get_jiggle_joint_use_gravity(which);
+		} else if (what == "gravity") {
+			r_ret = get_jiggle_joint_gravity(which);
+		}
+		return true;
+	} else {
+		if (path == "use_colliders") {
+			r_ret = get_use_colliders();
+		} else if (path == "collision_mask") {
+			r_ret = get_collision_mask();
+		}
+	}
+	return true;
+}
+
+void SkeletonModification2DJiggle::_get_property_list(List<PropertyInfo> *p_list) const {
+	p_list->push_back(PropertyInfo(Variant::BOOL, "use_colliders", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	if (use_colliders) {
+		p_list->push_back(PropertyInfo(Variant::INT, "collision_mask", PROPERTY_HINT_LAYERS_2D_PHYSICS, "", PROPERTY_USAGE_DEFAULT));
+	}
+
+	for (int i = 0; i < jiggle_data_chain.size(); i++) {
+		String base_string = "joint_data/" + itos(i) + "/";
+
+		p_list->push_back(PropertyInfo(Variant::INT, base_string + "bone_index", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::NODE_PATH, base_string + "bone2d_node", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Bone2D", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::BOOL, base_string + "override_defaults", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+
+		if (jiggle_data_chain[i].override_defaults) {
+			p_list->push_back(PropertyInfo(Variant::FLOAT, base_string + "stiffness", PROPERTY_HINT_RANGE, "0, 1000, 0.01", PROPERTY_USAGE_DEFAULT));
+			p_list->push_back(PropertyInfo(Variant::FLOAT, base_string + "mass", PROPERTY_HINT_RANGE, "0, 1000, 0.01", PROPERTY_USAGE_DEFAULT));
+			p_list->push_back(PropertyInfo(Variant::FLOAT, base_string + "damping", PROPERTY_HINT_RANGE, "0, 1, 0.01", PROPERTY_USAGE_DEFAULT));
+			p_list->push_back(PropertyInfo(Variant::BOOL, base_string + "use_gravity", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+			if (jiggle_data_chain[i].use_gravity) {
+				p_list->push_back(PropertyInfo(Variant::VECTOR2, base_string + "gravity", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+			}
+		}
+	}
+}
+
+void SkeletonModification2DJiggle::_execute(float p_delta) {
+	ERR_FAIL_COND_MSG(!stack || !is_setup || stack->skeleton == nullptr,
+			"Modification is not setup and therefore cannot execute!");
+	if (!enabled) {
+		return;
+	}
+	if (target_node_cache.is_null()) {
+		WARN_PRINT_ONCE("Target cache is out of date. Attempting to update...");
+		update_target_cache();
+		return;
+	}
+	Node2D *target = Object::cast_to<Node2D>(ObjectDB::get_instance(target_node_cache));
+	if (!target || !target->is_inside_tree()) {
+		ERR_PRINT_ONCE("Target node is not in the scene tree. Cannot execute modification!");
+		return;
+	}
+
+	for (int i = 0; i < jiggle_data_chain.size(); i++) {
+		_execute_jiggle_joint(i, target, p_delta);
+	}
+}
+
+void SkeletonModification2DJiggle::_execute_jiggle_joint(int p_joint_idx, Node2D *p_target, float p_delta) {
+	// Adopted from: https://wiki.unity3d.com/index.php/JiggleBone
+	// With modifications by TwistedTwigleg.
+
+	if (jiggle_data_chain[p_joint_idx].bone_idx <= -1 || jiggle_data_chain[p_joint_idx].bone_idx > stack->skeleton->get_bone_count()) {
+		ERR_PRINT_ONCE("Jiggle joint " + itos(p_joint_idx) + " bone index is invalid. Cannot execute modification on joint...");
+		return;
+	}
+
+	if (jiggle_data_chain[p_joint_idx].bone2d_node_cache.is_null() && !jiggle_data_chain[p_joint_idx].bone2d_node.is_empty()) {
+		WARN_PRINT_ONCE("Bone2D cache for joint " + itos(p_joint_idx) + " is out of date. Updating...");
+		jiggle_joint_update_bone2d_cache(p_joint_idx);
+	}
+
+	Bone2D *operation_bone = stack->skeleton->get_bone(jiggle_data_chain[p_joint_idx].bone_idx);
+	if (!operation_bone) {
+		ERR_PRINT_ONCE("Jiggle joint " + itos(p_joint_idx) + " does not have a Bone2D node or it cannot be found!");
+		return;
+	}
+
+	Transform2D operation_bone_trans = operation_bone->get_global_transform();
+	Vector2 target_position = p_target->get_global_transform().get_origin();
+
+	jiggle_data_chain.write[p_joint_idx].force = (target_position - jiggle_data_chain[p_joint_idx].dynamic_position) * jiggle_data_chain[p_joint_idx].stiffness * p_delta;
+
+	if (jiggle_data_chain[p_joint_idx].use_gravity) {
+		jiggle_data_chain.write[p_joint_idx].force += jiggle_data_chain[p_joint_idx].gravity * p_delta;
+	}
+
+	jiggle_data_chain.write[p_joint_idx].acceleration = jiggle_data_chain[p_joint_idx].force / jiggle_data_chain[p_joint_idx].mass;
+	jiggle_data_chain.write[p_joint_idx].velocity += jiggle_data_chain[p_joint_idx].acceleration * (1 - jiggle_data_chain[p_joint_idx].damping);
+
+	jiggle_data_chain.write[p_joint_idx].dynamic_position += jiggle_data_chain[p_joint_idx].velocity + jiggle_data_chain[p_joint_idx].force;
+	jiggle_data_chain.write[p_joint_idx].dynamic_position += operation_bone_trans.get_origin() - jiggle_data_chain[p_joint_idx].last_position;
+	jiggle_data_chain.write[p_joint_idx].last_position = operation_bone_trans.get_origin();
+
+	// Collision detection/response
+	if (use_colliders) {
+		if (execution_mode == SkeletonModificationStack2D::EXECUTION_MODE::execution_mode_physics_process) {
+			Ref<World2D> world_2d = stack->skeleton->get_world_2d();
+			ERR_FAIL_COND(world_2d.is_null());
+			PhysicsDirectSpaceState2D *space_state = PhysicsServer2D::get_singleton()->space_get_direct_state(world_2d->get_space());
+			PhysicsDirectSpaceState2D::RayResult ray_result;
+
+			// Add exception support?
+			bool ray_hit = space_state->intersect_ray(operation_bone_trans.get_origin(), jiggle_data_chain[p_joint_idx].dynamic_position,
+					ray_result, Set<RID>(), collision_mask);
+
+			if (ray_hit) {
+				jiggle_data_chain.write[p_joint_idx].dynamic_position = jiggle_data_chain[p_joint_idx].last_noncollision_position;
+				jiggle_data_chain.write[p_joint_idx].acceleration = Vector2(0, 0);
+				jiggle_data_chain.write[p_joint_idx].velocity = Vector2(0, 0);
+			} else {
+				jiggle_data_chain.write[p_joint_idx].last_noncollision_position = jiggle_data_chain[p_joint_idx].dynamic_position;
+			}
+		} else {
+			WARN_PRINT_ONCE("Jiggle 2D modifier: You cannot detect colliders without the stack mode being set to _physics_process!");
+		}
+	}
+
+	// Rotate the bone using the dynamic position!
+	operation_bone_trans = operation_bone_trans.looking_at(jiggle_data_chain[p_joint_idx].dynamic_position);
+	operation_bone_trans.set_rotation(operation_bone_trans.get_rotation() - operation_bone->get_bone_angle());
+
+	// Reset scale
+	operation_bone_trans.set_scale(operation_bone->get_global_transform().get_scale());
+
+	operation_bone->set_global_transform(operation_bone_trans);
+	stack->skeleton->set_bone_local_pose_override(jiggle_data_chain[p_joint_idx].bone_idx, operation_bone->get_transform(), stack->strength, true);
+}
+
+void SkeletonModification2DJiggle::_update_jiggle_joint_data() {
+	for (int i = 0; i < jiggle_data_chain.size(); i++) {
+		if (!jiggle_data_chain[i].override_defaults) {
+			set_jiggle_joint_stiffness(i, stiffness);
+			set_jiggle_joint_mass(i, mass);
+			set_jiggle_joint_damping(i, damping);
+			set_jiggle_joint_use_gravity(i, use_gravity);
+			set_jiggle_joint_gravity(i, gravity);
+		}
+	}
+}
+
+void SkeletonModification2DJiggle::_setup_modification(SkeletonModificationStack2D *p_stack) {
+	stack = p_stack;
+
+	if (stack) {
+		is_setup = true;
+
+		if (stack->skeleton) {
+			for (int i = 0; i < jiggle_data_chain.size(); i++) {
+				int bone_idx = jiggle_data_chain[i].bone_idx;
+				if (bone_idx > 0 && bone_idx < stack->skeleton->get_bone_count()) {
+					Bone2D *bone2d_node = stack->skeleton->get_bone(bone_idx);
+					jiggle_data_chain.write[i].dynamic_position = bone2d_node->get_global_transform().get_origin();
+				}
+			}
+		}
+
+		update_target_cache();
+	}
+}
+
+void SkeletonModification2DJiggle::update_target_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update target cache: modification is not properly setup!");
+		return;
+	}
+
+	target_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(target_node)) {
+				Node *node = stack->skeleton->get_node(target_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update target cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update target cache: node is not in scene tree!");
+				target_node_cache = node->get_instance_id();
+			}
+		}
+	}
+}
+
+void SkeletonModification2DJiggle::jiggle_joint_update_bone2d_cache(int p_joint_idx) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, jiggle_data_chain.size(), "Cannot update bone2d cache: joint index out of range!");
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update Jiggle " + itos(p_joint_idx) + " Bone2D cache: modification is not properly setup!");
+		return;
+	}
+
+	jiggle_data_chain.write[p_joint_idx].bone2d_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(jiggle_data_chain[p_joint_idx].bone2d_node)) {
+				Node *node = stack->skeleton->get_node(jiggle_data_chain[p_joint_idx].bone2d_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update Jiggle joint " + itos(p_joint_idx) + " Bone2D cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update Jiggle joint " + itos(p_joint_idx) + " Bone2D cache: node is not in scene tree!");
+				jiggle_data_chain.write[p_joint_idx].bone2d_node_cache = node->get_instance_id();
+
+				Bone2D *bone = Object::cast_to<Bone2D>(node);
+				if (bone) {
+					jiggle_data_chain.write[p_joint_idx].bone_idx = bone->get_index_in_skeleton();
+				} else {
+					ERR_FAIL_MSG("Jiggle joint " + itos(p_joint_idx) + " Bone2D cache: Nodepath to Bone2D is not a Bone2D node!");
+				}
+			}
+		}
+	}
+}
+
+void SkeletonModification2DJiggle::set_target_node(const NodePath &p_target_node) {
+	target_node = p_target_node;
+	update_target_cache();
+}
+
+NodePath SkeletonModification2DJiggle::get_target_node() const {
+	return target_node;
+}
+
+void SkeletonModification2DJiggle::set_stiffness(float p_stiffness) {
+	ERR_FAIL_COND_MSG(p_stiffness < 0, "Stiffness cannot be set to a negative value!");
+	stiffness = p_stiffness;
+	_update_jiggle_joint_data();
+}
+
+float SkeletonModification2DJiggle::get_stiffness() const {
+	return stiffness;
+}
+
+void SkeletonModification2DJiggle::set_mass(float p_mass) {
+	ERR_FAIL_COND_MSG(p_mass < 0, "Mass cannot be set to a negative value!");
+	mass = p_mass;
+	_update_jiggle_joint_data();
+}
+
+float SkeletonModification2DJiggle::get_mass() const {
+	return mass;
+}
+
+void SkeletonModification2DJiggle::set_damping(float p_damping) {
+	ERR_FAIL_COND_MSG(p_damping < 0, "Damping cannot be set to a negative value!");
+	ERR_FAIL_COND_MSG(p_damping > 1, "Damping cannot be more than one!");
+	damping = p_damping;
+	_update_jiggle_joint_data();
+}
+
+float SkeletonModification2DJiggle::get_damping() const {
+	return damping;
+}
+
+void SkeletonModification2DJiggle::set_use_gravity(bool p_use_gravity) {
+	use_gravity = p_use_gravity;
+	_update_jiggle_joint_data();
+}
+
+bool SkeletonModification2DJiggle::get_use_gravity() const {
+	return use_gravity;
+}
+
+void SkeletonModification2DJiggle::set_gravity(Vector2 p_gravity) {
+	gravity = p_gravity;
+	_update_jiggle_joint_data();
+}
+
+Vector2 SkeletonModification2DJiggle::get_gravity() const {
+	return gravity;
+}
+
+void SkeletonModification2DJiggle::set_use_colliders(bool p_use_colliders) {
+	use_colliders = p_use_colliders;
+	notify_property_list_changed();
+}
+
+bool SkeletonModification2DJiggle::get_use_colliders() const {
+	return use_colliders;
+}
+
+void SkeletonModification2DJiggle::set_collision_mask(int p_mask) {
+	collision_mask = p_mask;
+}
+
+int SkeletonModification2DJiggle::get_collision_mask() const {
+	return collision_mask;
+}
+
+// Jiggle joint data functions
+int SkeletonModification2DJiggle::get_jiggle_data_chain_length() {
+	return jiggle_data_chain.size();
+}
+
+void SkeletonModification2DJiggle::set_jiggle_data_chain_length(int p_length) {
+	ERR_FAIL_COND(p_length < 0);
+	jiggle_data_chain.resize(p_length);
+	notify_property_list_changed();
+}
+
+void SkeletonModification2DJiggle::set_jiggle_joint_bone2d_node(int p_joint_idx, const NodePath &p_target_node) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, jiggle_data_chain.size(), "Jiggle joint out of range!");
+	jiggle_data_chain.write[p_joint_idx].bone2d_node = p_target_node;
+	jiggle_joint_update_bone2d_cache(p_joint_idx);
+
+	notify_property_list_changed();
+}
+
+NodePath SkeletonModification2DJiggle::get_jiggle_joint_bone2d_node(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, jiggle_data_chain.size(), NodePath(), "Jiggle joint out of range!");
+	return jiggle_data_chain[p_joint_idx].bone2d_node;
+}
+
+void SkeletonModification2DJiggle::set_jiggle_joint_bone_index(int p_joint_idx, int p_bone_idx) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, jiggle_data_chain.size(), "Jiggle joint out of range!");
+	ERR_FAIL_COND_MSG(p_bone_idx < 0, "Bone index is out of range: The index is too low!");
+
+	if (is_setup) {
+		if (stack->skeleton) {
+			ERR_FAIL_INDEX_MSG(p_bone_idx, stack->skeleton->get_bone_count(), "Passed-in Bone index is out of range!");
+			jiggle_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+			jiggle_data_chain.write[p_joint_idx].bone2d_node_cache = stack->skeleton->get_bone(p_bone_idx)->get_instance_id();
+			jiggle_data_chain.write[p_joint_idx].bone2d_node = stack->skeleton->get_path_to(stack->skeleton->get_bone(p_bone_idx));
+		} else {
+			WARN_PRINT("Cannot verify the Jiggle joint " + itos(p_joint_idx) + " bone index for this modification...");
+			jiggle_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+		}
+	} else {
+		WARN_PRINT("Cannot verify the Jiggle joint " + itos(p_joint_idx) + " bone index for this modification...");
+		jiggle_data_chain.write[p_joint_idx].bone_idx = p_bone_idx;
+	}
+
+	notify_property_list_changed();
+}
+
+int SkeletonModification2DJiggle::get_jiggle_joint_bone_index(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, jiggle_data_chain.size(), -1, "Jiggle joint out of range!");
+	return jiggle_data_chain[p_joint_idx].bone_idx;
+}
+
+void SkeletonModification2DJiggle::set_jiggle_joint_override(int p_joint_idx, bool p_override) {
+	ERR_FAIL_INDEX(p_joint_idx, jiggle_data_chain.size());
+	jiggle_data_chain.write[p_joint_idx].override_defaults = p_override;
+	_update_jiggle_joint_data();
+	notify_property_list_changed();
+}
+
+bool SkeletonModification2DJiggle::get_jiggle_joint_override(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V(p_joint_idx, jiggle_data_chain.size(), false);
+	return jiggle_data_chain[p_joint_idx].override_defaults;
+}
+
+void SkeletonModification2DJiggle::set_jiggle_joint_stiffness(int p_joint_idx, float p_stiffness) {
+	ERR_FAIL_COND_MSG(p_stiffness < 0, "Stiffness cannot be set to a negative value!");
+	ERR_FAIL_INDEX(p_joint_idx, jiggle_data_chain.size());
+	jiggle_data_chain.write[p_joint_idx].stiffness = p_stiffness;
+}
+
+float SkeletonModification2DJiggle::get_jiggle_joint_stiffness(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V(p_joint_idx, jiggle_data_chain.size(), -1);
+	return jiggle_data_chain[p_joint_idx].stiffness;
+}
+
+void SkeletonModification2DJiggle::set_jiggle_joint_mass(int p_joint_idx, float p_mass) {
+	ERR_FAIL_COND_MSG(p_mass < 0, "Mass cannot be set to a negative value!");
+	ERR_FAIL_INDEX(p_joint_idx, jiggle_data_chain.size());
+	jiggle_data_chain.write[p_joint_idx].mass = p_mass;
+}
+
+float SkeletonModification2DJiggle::get_jiggle_joint_mass(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V(p_joint_idx, jiggle_data_chain.size(), -1);
+	return jiggle_data_chain[p_joint_idx].mass;
+}
+
+void SkeletonModification2DJiggle::set_jiggle_joint_damping(int p_joint_idx, float p_damping) {
+	ERR_FAIL_COND_MSG(p_damping < 0, "Damping cannot be set to a negative value!");
+	ERR_FAIL_INDEX(p_joint_idx, jiggle_data_chain.size());
+	jiggle_data_chain.write[p_joint_idx].damping = p_damping;
+}
+
+float SkeletonModification2DJiggle::get_jiggle_joint_damping(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V(p_joint_idx, jiggle_data_chain.size(), -1);
+	return jiggle_data_chain[p_joint_idx].damping;
+}
+
+void SkeletonModification2DJiggle::set_jiggle_joint_use_gravity(int p_joint_idx, bool p_use_gravity) {
+	ERR_FAIL_INDEX(p_joint_idx, jiggle_data_chain.size());
+	jiggle_data_chain.write[p_joint_idx].use_gravity = p_use_gravity;
+	notify_property_list_changed();
+}
+
+bool SkeletonModification2DJiggle::get_jiggle_joint_use_gravity(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V(p_joint_idx, jiggle_data_chain.size(), false);
+	return jiggle_data_chain[p_joint_idx].use_gravity;
+}
+
+void SkeletonModification2DJiggle::set_jiggle_joint_gravity(int p_joint_idx, Vector2 p_gravity) {
+	ERR_FAIL_INDEX(p_joint_idx, jiggle_data_chain.size());
+	jiggle_data_chain.write[p_joint_idx].gravity = p_gravity;
+}
+
+Vector2 SkeletonModification2DJiggle::get_jiggle_joint_gravity(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V(p_joint_idx, jiggle_data_chain.size(), Vector2(0, 0));
+	return jiggle_data_chain[p_joint_idx].gravity;
+}
+
+void SkeletonModification2DJiggle::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_target_node", "target_nodepath"), &SkeletonModification2DJiggle::set_target_node);
+	ClassDB::bind_method(D_METHOD("get_target_node"), &SkeletonModification2DJiggle::get_target_node);
+
+	ClassDB::bind_method(D_METHOD("set_jiggle_data_chain_length", "length"), &SkeletonModification2DJiggle::set_jiggle_data_chain_length);
+	ClassDB::bind_method(D_METHOD("get_jiggle_data_chain_length"), &SkeletonModification2DJiggle::get_jiggle_data_chain_length);
+
+	ClassDB::bind_method(D_METHOD("set_stiffness", "stiffness"), &SkeletonModification2DJiggle::set_stiffness);
+	ClassDB::bind_method(D_METHOD("get_stiffness"), &SkeletonModification2DJiggle::get_stiffness);
+	ClassDB::bind_method(D_METHOD("set_mass", "mass"), &SkeletonModification2DJiggle::set_mass);
+	ClassDB::bind_method(D_METHOD("get_mass"), &SkeletonModification2DJiggle::get_mass);
+	ClassDB::bind_method(D_METHOD("set_damping", "damping"), &SkeletonModification2DJiggle::set_damping);
+	ClassDB::bind_method(D_METHOD("get_damping"), &SkeletonModification2DJiggle::get_damping);
+	ClassDB::bind_method(D_METHOD("set_use_gravity", "use_gravity"), &SkeletonModification2DJiggle::set_use_gravity);
+	ClassDB::bind_method(D_METHOD("get_use_gravity"), &SkeletonModification2DJiggle::get_use_gravity);
+	ClassDB::bind_method(D_METHOD("set_gravity", "gravity"), &SkeletonModification2DJiggle::set_gravity);
+	ClassDB::bind_method(D_METHOD("get_gravity"), &SkeletonModification2DJiggle::get_gravity);
+
+	ClassDB::bind_method(D_METHOD("set_use_colliders", "use_colliders"), &SkeletonModification2DJiggle::set_use_colliders);
+	ClassDB::bind_method(D_METHOD("get_use_colliders"), &SkeletonModification2DJiggle::get_use_colliders);
+	ClassDB::bind_method(D_METHOD("set_collision_mask", "collision_mask"), &SkeletonModification2DJiggle::set_collision_mask);
+	ClassDB::bind_method(D_METHOD("get_collision_mask"), &SkeletonModification2DJiggle::get_collision_mask);
+
+	// Jiggle joint data functions
+	ClassDB::bind_method(D_METHOD("set_jiggle_joint_bone2d_node", "joint_idx", "bone2d_node"), &SkeletonModification2DJiggle::set_jiggle_joint_bone2d_node);
+	ClassDB::bind_method(D_METHOD("get_jiggle_joint_bone2d_node", "joint_idx"), &SkeletonModification2DJiggle::get_jiggle_joint_bone2d_node);
+	ClassDB::bind_method(D_METHOD("set_jiggle_joint_bone_index", "joint_idx", "bone_idx"), &SkeletonModification2DJiggle::set_jiggle_joint_bone_index);
+	ClassDB::bind_method(D_METHOD("get_jiggle_joint_bone_index", "joint_idx"), &SkeletonModification2DJiggle::get_jiggle_joint_bone_index);
+	ClassDB::bind_method(D_METHOD("set_jiggle_joint_override", "joint_idx", "override"), &SkeletonModification2DJiggle::set_jiggle_joint_override);
+	ClassDB::bind_method(D_METHOD("get_jiggle_joint_override", "joint_idx"), &SkeletonModification2DJiggle::get_jiggle_joint_override);
+	ClassDB::bind_method(D_METHOD("set_jiggle_joint_stiffness", "joint_idx", "stiffness"), &SkeletonModification2DJiggle::set_jiggle_joint_stiffness);
+	ClassDB::bind_method(D_METHOD("get_jiggle_joint_stiffness", "joint_idx"), &SkeletonModification2DJiggle::get_jiggle_joint_stiffness);
+	ClassDB::bind_method(D_METHOD("set_jiggle_joint_mass", "joint_idx", "mass"), &SkeletonModification2DJiggle::set_jiggle_joint_mass);
+	ClassDB::bind_method(D_METHOD("get_jiggle_joint_mass", "joint_idx"), &SkeletonModification2DJiggle::get_jiggle_joint_mass);
+	ClassDB::bind_method(D_METHOD("set_jiggle_joint_damping", "joint_idx", "damping"), &SkeletonModification2DJiggle::set_jiggle_joint_damping);
+	ClassDB::bind_method(D_METHOD("get_jiggle_joint_damping", "joint_idx"), &SkeletonModification2DJiggle::get_jiggle_joint_damping);
+	ClassDB::bind_method(D_METHOD("set_jiggle_joint_use_gravity", "joint_idx", "use_gravity"), &SkeletonModification2DJiggle::set_jiggle_joint_use_gravity);
+	ClassDB::bind_method(D_METHOD("get_jiggle_joint_use_gravity", "joint_idx"), &SkeletonModification2DJiggle::get_jiggle_joint_use_gravity);
+	ClassDB::bind_method(D_METHOD("set_jiggle_joint_gravity", "joint_idx", "gravity"), &SkeletonModification2DJiggle::set_jiggle_joint_gravity);
+	ClassDB::bind_method(D_METHOD("get_jiggle_joint_gravity", "joint_idx"), &SkeletonModification2DJiggle::get_jiggle_joint_gravity);
+
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "target_nodepath", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Node2D"), "set_target_node", "get_target_node");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "jiggle_data_chain_length", PROPERTY_HINT_RANGE, "0,100,1"), "set_jiggle_data_chain_length", "get_jiggle_data_chain_length");
+	ADD_GROUP("Default Joint Settings", "");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "stiffness"), "set_stiffness", "get_stiffness");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "mass"), "set_mass", "get_mass");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "damping", PROPERTY_HINT_RANGE, "0, 1, 0.01"), "set_damping", "get_damping");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_gravity"), "set_use_gravity", "get_use_gravity");
+	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "gravity"), "set_gravity", "get_gravity");
+	ADD_GROUP("", "");
+}
+
+SkeletonModification2DJiggle::SkeletonModification2DJiggle() {
+	stack = nullptr;
+	is_setup = false;
+	jiggle_data_chain = Vector<Jiggle_Joint_Data2D>();
+	stiffness = 3;
+	mass = 0.75;
+	damping = 0.75;
+	use_gravity = false;
+	gravity = Vector2(0, 6.0);
+	enabled = true;
+	editor_draw_gizmo = false; // Nothing to really show in a gizmo right now.
+}
+
+SkeletonModification2DJiggle::~SkeletonModification2DJiggle() {
+}
diff --git a/scene/resources/skeleton_modification_2d_jiggle.h b/scene/resources/skeleton_modification_2d_jiggle.h
new file mode 100644
index 0000000000..e24038a1db
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_jiggle.h
@@ -0,0 +1,139 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_jiggle.h                                    */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATION2DJIGGLE_H
+#define SKELETONMODIFICATION2DJIGGLE_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+
+///////////////////////////////////////
+// SkeletonModification2DJIGGLE
+///////////////////////////////////////
+
+class SkeletonModification2DJiggle : public SkeletonModification2D {
+	GDCLASS(SkeletonModification2DJiggle, SkeletonModification2D);
+
+private:
+	struct Jiggle_Joint_Data2D {
+		int bone_idx = -1;
+		NodePath bone2d_node;
+		ObjectID bone2d_node_cache;
+
+		bool override_defaults = false;
+		float stiffness = 3;
+		float mass = 0.75;
+		float damping = 0.75;
+		bool use_gravity = false;
+		Vector2 gravity = Vector2(0, 6.0);
+
+		Vector2 force = Vector2(0, 0);
+		Vector2 acceleration = Vector2(0, 0);
+		Vector2 velocity = Vector2(0, 0);
+		Vector2 last_position = Vector2(0, 0);
+		Vector2 dynamic_position = Vector2(0, 0);
+
+		Vector2 last_noncollision_position = Vector2(0, 0);
+	};
+
+	Vector<Jiggle_Joint_Data2D> jiggle_data_chain;
+
+	NodePath target_node;
+	ObjectID target_node_cache;
+	void update_target_cache();
+
+	float stiffness = 3;
+	float mass = 0.75;
+	float damping = 0.75;
+	bool use_gravity = false;
+	Vector2 gravity = Vector2(0, 6);
+
+	bool use_colliders = false;
+	uint32_t collision_mask = 1;
+
+	void jiggle_joint_update_bone2d_cache(int p_joint_idx);
+	void _execute_jiggle_joint(int p_joint_idx, Node2D *p_target, float p_delta);
+	void _update_jiggle_joint_data();
+
+protected:
+	static void _bind_methods();
+	bool _set(const StringName &p_path, const Variant &p_value);
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+
+public:
+	void _execute(float p_delta) override;
+	void _setup_modification(SkeletonModificationStack2D *p_stack) override;
+
+	void set_target_node(const NodePath &p_target_node);
+	NodePath get_target_node() const;
+
+	void set_stiffness(float p_stiffness);
+	float get_stiffness() const;
+	void set_mass(float p_mass);
+	float get_mass() const;
+	void set_damping(float p_damping);
+	float get_damping() const;
+	void set_use_gravity(bool p_use_gravity);
+	bool get_use_gravity() const;
+	void set_gravity(Vector2 p_gravity);
+	Vector2 get_gravity() const;
+
+	void set_use_colliders(bool p_use_colliders);
+	bool get_use_colliders() const;
+	void set_collision_mask(int p_mask);
+	int get_collision_mask() const;
+
+	int get_jiggle_data_chain_length();
+	void set_jiggle_data_chain_length(int p_new_length);
+
+	void set_jiggle_joint_bone2d_node(int p_joint_idx, const NodePath &p_target_node);
+	NodePath get_jiggle_joint_bone2d_node(int p_joint_idx) const;
+	void set_jiggle_joint_bone_index(int p_joint_idx, int p_bone_idx);
+	int get_jiggle_joint_bone_index(int p_joint_idx) const;
+
+	void set_jiggle_joint_override(int p_joint_idx, bool p_override);
+	bool get_jiggle_joint_override(int p_joint_idx) const;
+	void set_jiggle_joint_stiffness(int p_joint_idx, float p_stiffness);
+	float get_jiggle_joint_stiffness(int p_joint_idx) const;
+	void set_jiggle_joint_mass(int p_joint_idx, float p_mass);
+	float get_jiggle_joint_mass(int p_joint_idx) const;
+	void set_jiggle_joint_damping(int p_joint_idx, float p_damping);
+	float get_jiggle_joint_damping(int p_joint_idx) const;
+	void set_jiggle_joint_use_gravity(int p_joint_idx, bool p_use_gravity);
+	bool get_jiggle_joint_use_gravity(int p_joint_idx) const;
+	void set_jiggle_joint_gravity(int p_joint_idx, Vector2 p_gravity);
+	Vector2 get_jiggle_joint_gravity(int p_joint_idx) const;
+
+	SkeletonModification2DJiggle();
+	~SkeletonModification2DJiggle();
+};
+
+#endif // SKELETONMODIFICATION2DJIGGLE_H
diff --git a/scene/resources/skeleton_modification_2d_lookat.cpp b/scene/resources/skeleton_modification_2d_lookat.cpp
new file mode 100644
index 0000000000..fd5c8c7cc2
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_lookat.cpp
@@ -0,0 +1,407 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_lookat.cpp                                  */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_2d_lookat.h"
+#include "scene/2d/skeleton_2d.h"
+
+#ifdef TOOLS_ENABLED
+#include "editor/editor_settings.h"
+#endif // TOOLS_ENABLED
+
+bool SkeletonModification2DLookAt::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path.begins_with("enable_constraint")) {
+		set_enable_constraint(p_value);
+	} else if (path.begins_with("constraint_angle_min")) {
+		set_constraint_angle_min(Math::deg2rad(float(p_value)));
+	} else if (path.begins_with("constraint_angle_max")) {
+		set_constraint_angle_max(Math::deg2rad(float(p_value)));
+	} else if (path.begins_with("constraint_angle_invert")) {
+		set_constraint_angle_invert(p_value);
+	} else if (path.begins_with("constraint_in_localspace")) {
+		set_constraint_in_localspace(p_value);
+	} else if (path.begins_with("additional_rotation")) {
+		set_additional_rotation(Math::deg2rad(float(p_value)));
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path.begins_with("editor/draw_gizmo")) {
+		set_editor_draw_gizmo(p_value);
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+bool SkeletonModification2DLookAt::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path.begins_with("enable_constraint")) {
+		r_ret = get_enable_constraint();
+	} else if (path.begins_with("constraint_angle_min")) {
+		r_ret = Math::rad2deg(get_constraint_angle_min());
+	} else if (path.begins_with("constraint_angle_max")) {
+		r_ret = Math::rad2deg(get_constraint_angle_max());
+	} else if (path.begins_with("constraint_angle_invert")) {
+		r_ret = get_constraint_angle_invert();
+	} else if (path.begins_with("constraint_in_localspace")) {
+		r_ret = get_constraint_in_localspace();
+	} else if (path.begins_with("additional_rotation")) {
+		r_ret = Math::rad2deg(get_additional_rotation());
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path.begins_with("editor/draw_gizmo")) {
+		r_ret = get_editor_draw_gizmo();
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+void SkeletonModification2DLookAt::_get_property_list(List<PropertyInfo> *p_list) const {
+	p_list->push_back(PropertyInfo(Variant::BOOL, "enable_constraint", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	if (enable_constraint) {
+		p_list->push_back(PropertyInfo(Variant::FLOAT, "constraint_angle_min", PROPERTY_HINT_RANGE, "-360, 360, 0.01", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::FLOAT, "constraint_angle_max", PROPERTY_HINT_RANGE, "-360, 360, 0.01", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::BOOL, "constraint_angle_invert", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::BOOL, "constraint_in_localspace", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	}
+	p_list->push_back(PropertyInfo(Variant::FLOAT, "additional_rotation", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		p_list->push_back(PropertyInfo(Variant::BOOL, "editor/draw_gizmo", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	}
+#endif // TOOLS_ENABLED
+}
+
+void SkeletonModification2DLookAt::_execute(float p_delta) {
+	ERR_FAIL_COND_MSG(!stack || !is_setup || stack->skeleton == nullptr,
+			"Modification is not setup and therefore cannot execute!");
+	if (!enabled) {
+		return;
+	}
+
+	if (target_node_cache.is_null()) {
+		WARN_PRINT_ONCE("Target cache is out of date. Attempting to update...");
+		update_target_cache();
+		return;
+	}
+
+	if (bone2d_node_cache.is_null() && !bone2d_node.is_empty()) {
+		update_bone2d_cache();
+		WARN_PRINT_ONCE("Bone2D node cache is out of date. Attempting to update...");
+		return;
+	}
+
+	if (target_node_reference == nullptr) {
+		target_node_reference = Object::cast_to<Node2D>(ObjectDB::get_instance(target_node_cache));
+	}
+	if (!target_node_reference || !target_node_reference->is_inside_tree()) {
+		ERR_PRINT_ONCE("Target node is not in the scene tree. Cannot execute modification!");
+		return;
+	}
+	if (bone_idx <= -1) {
+		ERR_PRINT_ONCE("Bone index is invalid. Cannot execute modification!");
+		return;
+	}
+
+	Bone2D *operation_bone = stack->skeleton->get_bone(bone_idx);
+	if (operation_bone == nullptr) {
+		ERR_PRINT_ONCE("bone_idx for modification does not point to a valid bone! Cannot execute modification");
+		return;
+	}
+
+	Transform2D operation_transform = operation_bone->get_global_transform();
+	Transform2D target_trans = target_node_reference->get_global_transform();
+
+	// Look at the target!
+	operation_transform = operation_transform.looking_at(target_trans.get_origin());
+	// Apply whatever scale it had prior to looking_at
+	operation_transform.set_scale(operation_bone->get_global_transform().get_scale());
+
+	// Account for the direction the bone faces in:
+	operation_transform.set_rotation(operation_transform.get_rotation() - operation_bone->get_bone_angle());
+
+	// Apply additional rotation
+	operation_transform.set_rotation(operation_transform.get_rotation() + additional_rotation);
+
+	// Apply constraints in globalspace:
+	if (enable_constraint && !constraint_in_localspace) {
+		operation_transform.set_rotation(clamp_angle(operation_transform.get_rotation(), constraint_angle_min, constraint_angle_max, constraint_angle_invert));
+	}
+
+	// Convert from a global transform to a local transform via the Bone2D node
+	operation_bone->set_global_transform(operation_transform);
+	operation_transform = operation_bone->get_transform();
+
+	// Apply constraints in localspace:
+	if (enable_constraint && constraint_in_localspace) {
+		operation_transform.set_rotation(clamp_angle(operation_transform.get_rotation(), constraint_angle_min, constraint_angle_max, constraint_angle_invert));
+	}
+
+	// Set the local pose override, and to make sure child bones are also updated, set the transform of the bone.
+	stack->skeleton->set_bone_local_pose_override(bone_idx, operation_transform, stack->strength, true);
+	operation_bone->set_transform(operation_transform);
+}
+
+void SkeletonModification2DLookAt::_setup_modification(SkeletonModificationStack2D *p_stack) {
+	stack = p_stack;
+
+	if (stack != nullptr) {
+		is_setup = true;
+		update_target_cache();
+		update_bone2d_cache();
+	}
+}
+
+void SkeletonModification2DLookAt::_draw_editor_gizmo() {
+	if (!enabled || !is_setup) {
+		return;
+	}
+
+	Bone2D *operation_bone = stack->skeleton->get_bone(bone_idx);
+	editor_draw_angle_constraints(operation_bone, constraint_angle_min, constraint_angle_max,
+			enable_constraint, constraint_in_localspace, constraint_angle_invert);
+}
+
+void SkeletonModification2DLookAt::update_bone2d_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update Bone2D cache: modification is not properly setup!");
+		return;
+	}
+
+	bone2d_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(bone2d_node)) {
+				Node *node = stack->skeleton->get_node(bone2d_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update Bone2D cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update Bone2D cache: node is not in the scene tree!");
+				bone2d_node_cache = node->get_instance_id();
+
+				Bone2D *bone = Object::cast_to<Bone2D>(node);
+				if (bone) {
+					bone_idx = bone->get_index_in_skeleton();
+				} else {
+					ERR_FAIL_MSG("Error Bone2D cache: Nodepath to Bone2D is not a Bone2D node!");
+				}
+
+				// Set this to null so we update it
+				target_node_reference = nullptr;
+			}
+		}
+	}
+}
+
+void SkeletonModification2DLookAt::set_bone2d_node(const NodePath &p_target_node) {
+	bone2d_node = p_target_node;
+	update_bone2d_cache();
+}
+
+NodePath SkeletonModification2DLookAt::get_bone2d_node() const {
+	return bone2d_node;
+}
+
+int SkeletonModification2DLookAt::get_bone_index() const {
+	return bone_idx;
+}
+
+void SkeletonModification2DLookAt::set_bone_index(int p_bone_idx) {
+	ERR_FAIL_COND_MSG(p_bone_idx < 0, "Bone index is out of range: The index is too low!");
+
+	if (is_setup) {
+		if (stack->skeleton) {
+			ERR_FAIL_INDEX_MSG(p_bone_idx, stack->skeleton->get_bone_count(), "Passed-in Bone index is out of range!");
+			bone_idx = p_bone_idx;
+			bone2d_node_cache = stack->skeleton->get_bone(p_bone_idx)->get_instance_id();
+			bone2d_node = stack->skeleton->get_path_to(stack->skeleton->get_bone(p_bone_idx));
+		} else {
+			WARN_PRINT("Cannot verify the bone index for this modification...");
+			bone_idx = p_bone_idx;
+		}
+	} else {
+		WARN_PRINT("Cannot verify the bone index for this modification...");
+		bone_idx = p_bone_idx;
+	}
+
+	notify_property_list_changed();
+}
+
+void SkeletonModification2DLookAt::update_target_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update target cache: modification is not properly setup!");
+		return;
+	}
+
+	target_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(target_node)) {
+				Node *node = stack->skeleton->get_node(target_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update target cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update target cache: node is not in the scene tree!");
+				target_node_cache = node->get_instance_id();
+			}
+		}
+	}
+}
+
+void SkeletonModification2DLookAt::set_target_node(const NodePath &p_target_node) {
+	target_node = p_target_node;
+	update_target_cache();
+}
+
+NodePath SkeletonModification2DLookAt::get_target_node() const {
+	return target_node;
+}
+
+float SkeletonModification2DLookAt::get_additional_rotation() const {
+	return additional_rotation;
+}
+
+void SkeletonModification2DLookAt::set_additional_rotation(float p_rotation) {
+	additional_rotation = p_rotation;
+}
+
+void SkeletonModification2DLookAt::set_enable_constraint(bool p_constraint) {
+	enable_constraint = p_constraint;
+	notify_property_list_changed();
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2DLookAt::get_enable_constraint() const {
+	return enable_constraint;
+}
+
+void SkeletonModification2DLookAt::set_constraint_angle_min(float p_angle_min) {
+	constraint_angle_min = p_angle_min;
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+float SkeletonModification2DLookAt::get_constraint_angle_min() const {
+	return constraint_angle_min;
+}
+
+void SkeletonModification2DLookAt::set_constraint_angle_max(float p_angle_max) {
+	constraint_angle_max = p_angle_max;
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+float SkeletonModification2DLookAt::get_constraint_angle_max() const {
+	return constraint_angle_max;
+}
+
+void SkeletonModification2DLookAt::set_constraint_angle_invert(bool p_invert) {
+	constraint_angle_invert = p_invert;
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2DLookAt::get_constraint_angle_invert() const {
+	return constraint_angle_invert;
+}
+
+void SkeletonModification2DLookAt::set_constraint_in_localspace(bool p_constraint_in_localspace) {
+	constraint_in_localspace = p_constraint_in_localspace;
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2DLookAt::get_constraint_in_localspace() const {
+	return constraint_in_localspace;
+}
+
+void SkeletonModification2DLookAt::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_bone2d_node", "bone2d_nodepath"), &SkeletonModification2DLookAt::set_bone2d_node);
+	ClassDB::bind_method(D_METHOD("get_bone2d_node"), &SkeletonModification2DLookAt::get_bone2d_node);
+	ClassDB::bind_method(D_METHOD("set_bone_index", "bone_idx"), &SkeletonModification2DLookAt::set_bone_index);
+	ClassDB::bind_method(D_METHOD("get_bone_index"), &SkeletonModification2DLookAt::get_bone_index);
+
+	ClassDB::bind_method(D_METHOD("set_target_node", "target_nodepath"), &SkeletonModification2DLookAt::set_target_node);
+	ClassDB::bind_method(D_METHOD("get_target_node"), &SkeletonModification2DLookAt::get_target_node);
+
+	ClassDB::bind_method(D_METHOD("set_additional_rotation", "rotation"), &SkeletonModification2DLookAt::set_additional_rotation);
+	ClassDB::bind_method(D_METHOD("get_additional_rotation"), &SkeletonModification2DLookAt::get_additional_rotation);
+
+	ClassDB::bind_method(D_METHOD("set_enable_constraint", "enable_constraint"), &SkeletonModification2DLookAt::set_enable_constraint);
+	ClassDB::bind_method(D_METHOD("get_enable_constraint"), &SkeletonModification2DLookAt::get_enable_constraint);
+	ClassDB::bind_method(D_METHOD("set_constraint_angle_min", "angle_min"), &SkeletonModification2DLookAt::set_constraint_angle_min);
+	ClassDB::bind_method(D_METHOD("get_constraint_angle_min"), &SkeletonModification2DLookAt::get_constraint_angle_min);
+	ClassDB::bind_method(D_METHOD("set_constraint_angle_max", "angle_max"), &SkeletonModification2DLookAt::set_constraint_angle_max);
+	ClassDB::bind_method(D_METHOD("get_constraint_angle_max"), &SkeletonModification2DLookAt::get_constraint_angle_max);
+	ClassDB::bind_method(D_METHOD("set_constraint_angle_invert", "invert"), &SkeletonModification2DLookAt::set_constraint_angle_invert);
+	ClassDB::bind_method(D_METHOD("get_constraint_angle_invert"), &SkeletonModification2DLookAt::get_constraint_angle_invert);
+
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "bone_index"), "set_bone_index", "get_bone_index");
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "bone2d_node", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Bone2D"), "set_bone2d_node", "get_bone2d_node");
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "target_nodepath", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Node2D"), "set_target_node", "get_target_node");
+}
+
+SkeletonModification2DLookAt::SkeletonModification2DLookAt() {
+	stack = nullptr;
+	is_setup = false;
+	bone_idx = -1;
+	additional_rotation = 0;
+	enable_constraint = false;
+	constraint_angle_min = 0;
+	constraint_angle_max = Math_PI * 2;
+	constraint_angle_invert = false;
+	enabled = true;
+
+	editor_draw_gizmo = true;
+}
+
+SkeletonModification2DLookAt::~SkeletonModification2DLookAt() {
+}
diff --git a/scene/resources/skeleton_modification_2d_lookat.h b/scene/resources/skeleton_modification_2d_lookat.h
new file mode 100644
index 0000000000..6aff30b826
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_lookat.h
@@ -0,0 +1,100 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_lookat.h                                    */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATION2DLOOKAT_H
+#define SKELETONMODIFICATION2DLOOKAT_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+
+///////////////////////////////////////
+// SkeletonModification2DLookAt
+///////////////////////////////////////
+
+class SkeletonModification2DLookAt : public SkeletonModification2D {
+	GDCLASS(SkeletonModification2DLookAt, SkeletonModification2D);
+
+private:
+	int bone_idx = -1;
+	NodePath bone2d_node;
+	ObjectID bone2d_node_cache;
+
+	NodePath target_node;
+	ObjectID target_node_cache;
+	Node2D *target_node_reference = nullptr;
+
+	float additional_rotation = 0;
+	bool enable_constraint = false;
+	float constraint_angle_min = 0;
+	float constraint_angle_max = (2.0 * Math_PI);
+	bool constraint_angle_invert = false;
+	bool constraint_in_localspace = true;
+
+	void update_bone2d_cache();
+	void update_target_cache();
+
+protected:
+	static void _bind_methods();
+	bool _set(const StringName &p_path, const Variant &p_value);
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+
+public:
+	void _execute(float p_delta) override;
+	void _setup_modification(SkeletonModificationStack2D *p_stack) override;
+	void _draw_editor_gizmo() override;
+
+	void set_bone2d_node(const NodePath &p_target_node);
+	NodePath get_bone2d_node() const;
+	void set_bone_index(int p_idx);
+	int get_bone_index() const;
+
+	void set_target_node(const NodePath &p_target_node);
+	NodePath get_target_node() const;
+
+	void set_additional_rotation(float p_rotation);
+	float get_additional_rotation() const;
+
+	void set_enable_constraint(bool p_constraint);
+	bool get_enable_constraint() const;
+	void set_constraint_angle_min(float p_angle_min);
+	float get_constraint_angle_min() const;
+	void set_constraint_angle_max(float p_angle_max);
+	float get_constraint_angle_max() const;
+	void set_constraint_angle_invert(bool p_invert);
+	bool get_constraint_angle_invert() const;
+	void set_constraint_in_localspace(bool p_constraint_in_localspace);
+	bool get_constraint_in_localspace() const;
+
+	SkeletonModification2DLookAt();
+	~SkeletonModification2DLookAt();
+};
+
+#endif // SKELETONMODIFICATION2DLOOKAT_H
diff --git a/scene/resources/skeleton_modification_2d_physicalbones.cpp b/scene/resources/skeleton_modification_2d_physicalbones.cpp
new file mode 100644
index 0000000000..9dedb93f36
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_physicalbones.cpp
@@ -0,0 +1,297 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_physicalbones.cpp                           */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_2d_physicalbones.h"
+#include "scene/2d/physical_bone_2d.h"
+#include "scene/2d/skeleton_2d.h"
+
+bool SkeletonModification2DPhysicalBones::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+#ifdef TOOLS_ENABLED
+	// Exposes a way to fetch the PhysicalBone2D nodes from the Godot editor.
+	if (is_setup) {
+		if (Engine::get_singleton()->is_editor_hint()) {
+			if (path.begins_with("fetch_bones")) {
+				fetch_physical_bones();
+				notify_property_list_changed();
+				return true;
+			}
+		}
+	}
+#endif //TOOLS_ENABLED
+
+	if (path.begins_with("joint_")) {
+		int which = path.get_slicec('_', 1).to_int();
+		String what = path.get_slicec('_', 2);
+		ERR_FAIL_INDEX_V(which, physical_bone_chain.size(), false);
+
+		if (what == "nodepath") {
+			set_physical_bone_node(which, p_value);
+		}
+		return true;
+	}
+	return true;
+}
+
+bool SkeletonModification2DPhysicalBones::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		if (path.begins_with("fetch_bones")) {
+			return true; // Do nothing!
+		}
+	}
+#endif //TOOLS_ENABLED
+
+	if (path.begins_with("joint_")) {
+		int which = path.get_slicec('_', 1).to_int();
+		String what = path.get_slicec('_', 2);
+		ERR_FAIL_INDEX_V(which, physical_bone_chain.size(), false);
+
+		if (what == "nodepath") {
+			r_ret = get_physical_bone_node(which);
+		}
+		return true;
+	}
+	return true;
+}
+
+void SkeletonModification2DPhysicalBones::_get_property_list(List<PropertyInfo> *p_list) const {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		p_list->push_back(PropertyInfo(Variant::BOOL, "fetch_bones", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	}
+#endif //TOOLS_ENABLED
+
+	for (int i = 0; i < physical_bone_chain.size(); i++) {
+		String base_string = "joint_" + itos(i) + "_";
+
+		p_list->push_back(PropertyInfo(Variant::NODE_PATH, base_string + "nodepath", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "PhysicalBone2D", PROPERTY_USAGE_DEFAULT));
+	}
+}
+
+void SkeletonModification2DPhysicalBones::_execute(float p_delta) {
+	ERR_FAIL_COND_MSG(!stack || !is_setup || stack->skeleton == nullptr,
+			"Modification is not setup and therefore cannot execute!");
+	if (!enabled) {
+		return;
+	}
+
+	if (_simulation_state_dirty) {
+		_update_simulation_state();
+	}
+
+	for (int i = 0; i < physical_bone_chain.size(); i++) {
+		PhysicalBone_Data2D bone_data = physical_bone_chain[i];
+		if (bone_data.physical_bone_node_cache.is_null()) {
+			WARN_PRINT_ONCE("PhysicalBone2D cache " + itos(i) + " is out of date. Attempting to update...");
+			_physical_bone_update_cache(i);
+			continue;
+		}
+
+		PhysicalBone2D *physical_bone = Object::cast_to<PhysicalBone2D>(ObjectDB::get_instance(bone_data.physical_bone_node_cache));
+		if (!physical_bone) {
+			ERR_PRINT_ONCE("PhysicalBone2D not found at index " + itos(i) + "!");
+			return;
+		}
+		if (physical_bone->get_bone2d_index() < 0 || physical_bone->get_bone2d_index() > stack->skeleton->get_bone_count()) {
+			ERR_PRINT_ONCE("PhysicalBone2D at index " + itos(i) + " has invalid Bone2D!");
+			return;
+		}
+		Bone2D *bone_2d = stack->skeleton->get_bone(physical_bone->get_bone2d_index());
+
+		if (physical_bone->get_simulate_physics() && !physical_bone->get_follow_bone_when_simulating()) {
+			bone_2d->set_global_transform(physical_bone->get_global_transform());
+			stack->skeleton->set_bone_local_pose_override(physical_bone->get_bone2d_index(), bone_2d->get_transform(), stack->strength, true);
+		}
+	}
+}
+
+void SkeletonModification2DPhysicalBones::_setup_modification(SkeletonModificationStack2D *p_stack) {
+	stack = p_stack;
+
+	if (stack) {
+		is_setup = true;
+
+		if (stack->skeleton) {
+			for (int i = 0; i < physical_bone_chain.size(); i++) {
+				_physical_bone_update_cache(i);
+			}
+		}
+	}
+}
+
+void SkeletonModification2DPhysicalBones::_physical_bone_update_cache(int p_joint_idx) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, physical_bone_chain.size(), "Cannot update PhysicalBone2D cache: joint index out of range!");
+	if (!is_setup || !stack) {
+		if (!stack) {
+			ERR_PRINT_ONCE("Cannot update PhysicalBone2D cache: modification is not properly setup!");
+		}
+		return;
+	}
+
+	physical_bone_chain.write[p_joint_idx].physical_bone_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(physical_bone_chain[p_joint_idx].physical_bone_node)) {
+				Node *node = stack->skeleton->get_node(physical_bone_chain[p_joint_idx].physical_bone_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update Physical Bone2D " + itos(p_joint_idx) + " cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update Physical Bone2D " + itos(p_joint_idx) + " cache: node is not in scene tree!");
+				physical_bone_chain.write[p_joint_idx].physical_bone_node_cache = node->get_instance_id();
+			}
+		}
+	}
+}
+
+int SkeletonModification2DPhysicalBones::get_physical_bone_chain_length() {
+	return physical_bone_chain.size();
+}
+
+void SkeletonModification2DPhysicalBones::set_physical_bone_chain_length(int p_length) {
+	ERR_FAIL_COND(p_length < 0);
+	physical_bone_chain.resize(p_length);
+	notify_property_list_changed();
+}
+
+void SkeletonModification2DPhysicalBones::fetch_physical_bones() {
+	ERR_FAIL_COND_MSG(!stack, "No modification stack found! Cannot fetch physical bones!");
+	ERR_FAIL_COND_MSG(!stack->skeleton, "No skeleton found! Cannot fetch physical bones!");
+
+	physical_bone_chain.clear();
+
+	List<Node *> node_queue = List<Node *>();
+	node_queue.push_back(stack->skeleton);
+
+	while (node_queue.size() > 0) {
+		Node *node_to_process = node_queue[0];
+		node_queue.pop_front();
+
+		if (node_to_process != nullptr) {
+			PhysicalBone2D *potential_bone = Object::cast_to<PhysicalBone2D>(node_to_process);
+			if (potential_bone) {
+				PhysicalBone_Data2D new_data = PhysicalBone_Data2D();
+				new_data.physical_bone_node = stack->skeleton->get_path_to(potential_bone);
+				new_data.physical_bone_node_cache = potential_bone->get_instance_id();
+				physical_bone_chain.push_back(new_data);
+			}
+			for (int i = 0; i < node_to_process->get_child_count(); i++) {
+				node_queue.push_back(node_to_process->get_child(i));
+			}
+		}
+	}
+}
+
+void SkeletonModification2DPhysicalBones::start_simulation(const TypedArray<StringName> &p_bones) {
+	_simulation_state_dirty = true;
+	_simulation_state_dirty_names = p_bones;
+	_simulation_state_dirty_process = true;
+
+	if (is_setup) {
+		_update_simulation_state();
+	}
+}
+
+void SkeletonModification2DPhysicalBones::stop_simulation(const TypedArray<StringName> &p_bones) {
+	_simulation_state_dirty = true;
+	_simulation_state_dirty_names = p_bones;
+	_simulation_state_dirty_process = false;
+
+	if (is_setup) {
+		_update_simulation_state();
+	}
+}
+
+void SkeletonModification2DPhysicalBones::_update_simulation_state() {
+	if (!_simulation_state_dirty) {
+		return;
+	}
+	_simulation_state_dirty = false;
+
+	if (_simulation_state_dirty_names.size() <= 0) {
+		for (int i = 0; i < physical_bone_chain.size(); i++) {
+			PhysicalBone2D *physical_bone = Object::cast_to<PhysicalBone2D>(stack->skeleton->get_node(physical_bone_chain[i].physical_bone_node));
+			if (!physical_bone) {
+				continue;
+			}
+
+			physical_bone->set_simulate_physics(_simulation_state_dirty_process);
+		}
+	} else {
+		for (int i = 0; i < physical_bone_chain.size(); i++) {
+			PhysicalBone2D *physical_bone = Object::cast_to<PhysicalBone2D>(ObjectDB::get_instance(physical_bone_chain[i].physical_bone_node_cache));
+			if (!physical_bone) {
+				continue;
+			}
+			if (_simulation_state_dirty_names.has(physical_bone->get_name())) {
+				physical_bone->set_simulate_physics(_simulation_state_dirty_process);
+			}
+		}
+	}
+}
+
+void SkeletonModification2DPhysicalBones::set_physical_bone_node(int p_joint_idx, const NodePath &p_nodepath) {
+	ERR_FAIL_INDEX_MSG(p_joint_idx, physical_bone_chain.size(), "Joint index out of range!");
+	physical_bone_chain.write[p_joint_idx].physical_bone_node = p_nodepath;
+	_physical_bone_update_cache(p_joint_idx);
+}
+
+NodePath SkeletonModification2DPhysicalBones::get_physical_bone_node(int p_joint_idx) const {
+	ERR_FAIL_INDEX_V_MSG(p_joint_idx, physical_bone_chain.size(), NodePath(), "Joint index out of range!");
+	return physical_bone_chain[p_joint_idx].physical_bone_node;
+}
+
+void SkeletonModification2DPhysicalBones::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_physical_bone_chain_length", "length"), &SkeletonModification2DPhysicalBones::set_physical_bone_chain_length);
+	ClassDB::bind_method(D_METHOD("get_physical_bone_chain_length"), &SkeletonModification2DPhysicalBones::get_physical_bone_chain_length);
+
+	ClassDB::bind_method(D_METHOD("set_physical_bone_node", "joint_idx", "physicalbone2d_node"), &SkeletonModification2DPhysicalBones::set_physical_bone_node);
+	ClassDB::bind_method(D_METHOD("get_physical_bone_node", "joint_idx"), &SkeletonModification2DPhysicalBones::get_physical_bone_node);
+
+	ClassDB::bind_method(D_METHOD("fetch_physical_bones"), &SkeletonModification2DPhysicalBones::fetch_physical_bones);
+	ClassDB::bind_method(D_METHOD("start_simulation", "bones"), &SkeletonModification2DPhysicalBones::start_simulation, DEFVAL(Array()));
+	ClassDB::bind_method(D_METHOD("stop_simulation", "bones"), &SkeletonModification2DPhysicalBones::stop_simulation, DEFVAL(Array()));
+
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "physical_bone_chain_length", PROPERTY_HINT_RANGE, "0,100,1"), "set_physical_bone_chain_length", "get_physical_bone_chain_length");
+}
+
+SkeletonModification2DPhysicalBones::SkeletonModification2DPhysicalBones() {
+	stack = nullptr;
+	is_setup = false;
+	physical_bone_chain = Vector<PhysicalBone_Data2D>();
+	enabled = true;
+	editor_draw_gizmo = false; // Nothing to really show in a gizmo right now.
+}
+
+SkeletonModification2DPhysicalBones::~SkeletonModification2DPhysicalBones() {
+}
diff --git a/scene/resources/skeleton_modification_2d_physicalbones.h b/scene/resources/skeleton_modification_2d_physicalbones.h
new file mode 100644
index 0000000000..cdf6a5f570
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_physicalbones.h
@@ -0,0 +1,82 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_physicalbones.h                             */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATION2DPHYSICALBONES_H
+#define SKELETONMODIFICATION2DPHYSICALBONES_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+
+///////////////////////////////////////
+// SkeletonModification2DJIGGLE
+///////////////////////////////////////
+
+class SkeletonModification2DPhysicalBones : public SkeletonModification2D {
+	GDCLASS(SkeletonModification2DPhysicalBones, SkeletonModification2D);
+
+private:
+	struct PhysicalBone_Data2D {
+		NodePath physical_bone_node;
+		ObjectID physical_bone_node_cache;
+	};
+	Vector<PhysicalBone_Data2D> physical_bone_chain;
+
+	void _physical_bone_update_cache(int p_joint_idx);
+
+	bool _simulation_state_dirty = false;
+	TypedArray<StringName> _simulation_state_dirty_names;
+	bool _simulation_state_dirty_process;
+	void _update_simulation_state();
+
+protected:
+	static void _bind_methods();
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	bool _set(const StringName &p_path, const Variant &p_value);
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+
+public:
+	void _execute(float p_delta) override;
+	void _setup_modification(SkeletonModificationStack2D *p_stack) override;
+
+	int get_physical_bone_chain_length();
+	void set_physical_bone_chain_length(int p_new_length);
+
+	void set_physical_bone_node(int p_joint_idx, const NodePath &p_path);
+	NodePath get_physical_bone_node(int p_joint_idx) const;
+
+	void fetch_physical_bones();
+	void start_simulation(const TypedArray<StringName> &p_bones);
+	void stop_simulation(const TypedArray<StringName> &p_bones);
+
+	SkeletonModification2DPhysicalBones();
+	~SkeletonModification2DPhysicalBones();
+};
+
+#endif // SKELETONMODIFICATION2DPHYSICALBONES_H
diff --git a/scene/resources/skeleton_modification_2d_stackholder.cpp b/scene/resources/skeleton_modification_2d_stackholder.cpp
new file mode 100644
index 0000000000..9436092cd9
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_stackholder.cpp
@@ -0,0 +1,131 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_stackholder.cpp                             */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_2d_stackholder.h"
+#include "scene/2d/skeleton_2d.h"
+
+bool SkeletonModification2DStackHolder::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path == "held_modification_stack") {
+		set_held_modification_stack(p_value);
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path == "editor/draw_gizmo") {
+		set_editor_draw_gizmo(p_value);
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+bool SkeletonModification2DStackHolder::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path == "held_modification_stack") {
+		r_ret = get_held_modification_stack();
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path == "editor/draw_gizmo") {
+		r_ret = get_editor_draw_gizmo();
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+void SkeletonModification2DStackHolder::_get_property_list(List<PropertyInfo> *p_list) const {
+	p_list->push_back(PropertyInfo(Variant::OBJECT, "held_modification_stack", PROPERTY_HINT_RESOURCE_TYPE, "SkeletonModificationStack2D", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_DO_NOT_SHARE_ON_DUPLICATE));
+
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		p_list->push_back(PropertyInfo(Variant::BOOL, "editor/draw_gizmo", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	}
+#endif // TOOLS_ENABLED
+}
+
+void SkeletonModification2DStackHolder::_execute(float p_delta) {
+	ERR_FAIL_COND_MSG(!stack || !is_setup || stack->skeleton == nullptr,
+			"Modification is not setup and therefore cannot execute!");
+
+	if (held_modification_stack.is_valid()) {
+		held_modification_stack->execute(p_delta, execution_mode);
+	}
+}
+
+void SkeletonModification2DStackHolder::_setup_modification(SkeletonModificationStack2D *p_stack) {
+	stack = p_stack;
+
+	if (stack != nullptr) {
+		is_setup = true;
+
+		if (held_modification_stack.is_valid()) {
+			held_modification_stack->set_skeleton(stack->get_skeleton());
+			held_modification_stack->setup();
+		}
+	}
+}
+
+void SkeletonModification2DStackHolder::_draw_editor_gizmo() {
+	if (stack) {
+		if (held_modification_stack.is_valid()) {
+			held_modification_stack->draw_editor_gizmos();
+		}
+	}
+}
+
+void SkeletonModification2DStackHolder::set_held_modification_stack(Ref<SkeletonModificationStack2D> p_held_stack) {
+	held_modification_stack = p_held_stack;
+
+	if (is_setup && held_modification_stack.is_valid()) {
+		held_modification_stack->set_skeleton(stack->get_skeleton());
+		held_modification_stack->setup();
+	}
+}
+
+Ref<SkeletonModificationStack2D> SkeletonModification2DStackHolder::get_held_modification_stack() const {
+	return held_modification_stack;
+}
+
+void SkeletonModification2DStackHolder::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_held_modification_stack", "held_modification_stack"), &SkeletonModification2DStackHolder::set_held_modification_stack);
+	ClassDB::bind_method(D_METHOD("get_held_modification_stack"), &SkeletonModification2DStackHolder::get_held_modification_stack);
+}
+
+SkeletonModification2DStackHolder::SkeletonModification2DStackHolder() {
+	stack = nullptr;
+	is_setup = false;
+	enabled = true;
+}
+
+SkeletonModification2DStackHolder::~SkeletonModification2DStackHolder() {
+}
diff --git a/scene/resources/skeleton_modification_2d_stackholder.h b/scene/resources/skeleton_modification_2d_stackholder.h
new file mode 100644
index 0000000000..9cc38e3942
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_stackholder.h
@@ -0,0 +1,64 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_stackholder.h                               */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATION2DSTACKHOLDER_H
+#define SKELETONMODIFICATION2DSTACKHOLDER_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+
+///////////////////////////////////////
+// SkeletonModification2DJIGGLE
+///////////////////////////////////////
+
+class SkeletonModification2DStackHolder : public SkeletonModification2D {
+	GDCLASS(SkeletonModification2DStackHolder, SkeletonModification2D);
+
+protected:
+	static void _bind_methods();
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	bool _set(const StringName &p_path, const Variant &p_value);
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+
+public:
+	Ref<SkeletonModificationStack2D> held_modification_stack;
+
+	void _execute(float p_delta) override;
+	void _setup_modification(SkeletonModificationStack2D *p_stack) override;
+	void _draw_editor_gizmo() override;
+
+	void set_held_modification_stack(Ref<SkeletonModificationStack2D> p_held_stack);
+	Ref<SkeletonModificationStack2D> get_held_modification_stack() const;
+
+	SkeletonModification2DStackHolder();
+	~SkeletonModification2DStackHolder();
+};
+
+#endif // SKELETONMODIFICATION2DSTACKHOLDER_H
diff --git a/scene/resources/skeleton_modification_2d_twoboneik.cpp b/scene/resources/skeleton_modification_2d_twoboneik.cpp
new file mode 100644
index 0000000000..0a91290015
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_twoboneik.cpp
@@ -0,0 +1,481 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_twoboneik.cpp                               */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_2d_twoboneik.h"
+#include "scene/2d/skeleton_2d.h"
+
+#ifdef TOOLS_ENABLED
+#include "editor/editor_settings.h"
+#endif // TOOLS_ENABLED
+
+bool SkeletonModification2DTwoBoneIK::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path == "joint_one_bone_idx") {
+		set_joint_one_bone_idx(p_value);
+	} else if (path == "joint_one_bone2d_node") {
+		set_joint_one_bone2d_node(p_value);
+	} else if (path == "joint_two_bone_idx") {
+		set_joint_two_bone_idx(p_value);
+	} else if (path == "joint_two_bone2d_node") {
+		set_joint_two_bone2d_node(p_value);
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path.begins_with("editor/draw_gizmo")) {
+		set_editor_draw_gizmo(p_value);
+	} else if (path.begins_with("editor/draw_min_max")) {
+		set_editor_draw_min_max(p_value);
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+bool SkeletonModification2DTwoBoneIK::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path == "joint_one_bone_idx") {
+		r_ret = get_joint_one_bone_idx();
+	} else if (path == "joint_one_bone2d_node") {
+		r_ret = get_joint_one_bone2d_node();
+	} else if (path == "joint_two_bone_idx") {
+		r_ret = get_joint_two_bone_idx();
+	} else if (path == "joint_two_bone2d_node") {
+		r_ret = get_joint_two_bone2d_node();
+	}
+
+#ifdef TOOLS_ENABLED
+	if (path.begins_with("editor/draw_gizmo")) {
+		r_ret = get_editor_draw_gizmo();
+	} else if (path.begins_with("editor/draw_min_max")) {
+		r_ret = get_editor_draw_min_max();
+	}
+#endif // TOOLS_ENABLED
+
+	return true;
+}
+
+void SkeletonModification2DTwoBoneIK::_get_property_list(List<PropertyInfo> *p_list) const {
+	p_list->push_back(PropertyInfo(Variant::INT, "joint_one_bone_idx", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	p_list->push_back(PropertyInfo(Variant::NODE_PATH, "joint_one_bone2d_node", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Bone2D", PROPERTY_USAGE_DEFAULT));
+
+	p_list->push_back(PropertyInfo(Variant::INT, "joint_two_bone_idx", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	p_list->push_back(PropertyInfo(Variant::NODE_PATH, "joint_two_bone2d_node", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Bone2D", PROPERTY_USAGE_DEFAULT));
+
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		p_list->push_back(PropertyInfo(Variant::BOOL, "editor/draw_gizmo", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+		p_list->push_back(PropertyInfo(Variant::BOOL, "editor/draw_min_max", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT));
+	}
+#endif // TOOLS_ENABLED
+}
+
+void SkeletonModification2DTwoBoneIK::_execute(float p_delta) {
+	ERR_FAIL_COND_MSG(!stack || !is_setup || stack->skeleton == nullptr,
+			"Modification is not setup and therefore cannot execute!");
+	if (!enabled) {
+		return;
+	}
+
+	if (target_node_cache.is_null()) {
+		WARN_PRINT_ONCE("Target cache is out of date. Attempting to update...");
+		update_target_cache();
+		return;
+	}
+
+	if (joint_one_bone2d_node_cache.is_null() && !joint_one_bone2d_node.is_empty()) {
+		WARN_PRINT_ONCE("Joint one Bone2D node cache is out of date. Attempting to update...");
+		update_joint_one_bone2d_cache();
+	}
+	if (joint_two_bone2d_node_cache.is_null() && !joint_two_bone2d_node.is_empty()) {
+		WARN_PRINT_ONCE("Joint two Bone2D node cache is out of date. Attempting to update...");
+		update_joint_two_bone2d_cache();
+	}
+
+	Node2D *target = Object::cast_to<Node2D>(ObjectDB::get_instance(target_node_cache));
+	if (!target || !target->is_inside_tree()) {
+		ERR_PRINT_ONCE("Target node is not in the scene tree. Cannot execute modification!");
+		return;
+	}
+
+	Bone2D *joint_one_bone = stack->skeleton->get_bone(joint_one_bone_idx);
+	if (joint_one_bone == nullptr) {
+		ERR_PRINT_ONCE("Joint one bone_idx does not point to a valid bone! Cannot execute modification!");
+		return;
+	}
+
+	Bone2D *joint_two_bone = stack->skeleton->get_bone(joint_two_bone_idx);
+	if (joint_two_bone == nullptr) {
+		ERR_PRINT_ONCE("Joint two bone_idx does not point to a valid bone! Cannot execute modification!");
+		return;
+	}
+
+	// Adopted from the links below:
+	// http://theorangeduck.com/page/simple-two-joint
+	// https://www.alanzucconi.com/2018/05/02/ik-2d-2/
+	// With modifications by TwistedTwigleg
+	Vector2 target_difference = target->get_global_transform().get_origin() - joint_one_bone->get_global_transform().get_origin();
+	float joint_one_to_target = target_difference.length();
+	float angle_atan = Math::atan2(target_difference.y, target_difference.x);
+
+	float bone_one_length = joint_one_bone->get_length() * MIN(joint_one_bone->get_global_scale().x, joint_one_bone->get_global_scale().y);
+	float bone_two_length = joint_two_bone->get_length() * MIN(joint_two_bone->get_global_scale().x, joint_two_bone->get_global_scale().y);
+	bool override_angles_due_to_out_of_range = false;
+
+	if (joint_one_to_target < target_minimum_distance) {
+		joint_one_to_target = target_minimum_distance;
+	}
+	if (joint_one_to_target > target_maximum_distance && target_maximum_distance > 0.0) {
+		joint_one_to_target = target_maximum_distance;
+	}
+
+	if (bone_one_length + bone_two_length < joint_one_to_target) {
+		override_angles_due_to_out_of_range = true;
+	}
+
+	if (!override_angles_due_to_out_of_range) {
+		float angle_0 = Math::acos(((joint_one_to_target * joint_one_to_target) + (bone_one_length * bone_one_length) - (bone_two_length * bone_two_length)) / (2.0 * joint_one_to_target * bone_one_length));
+		float angle_1 = Math::acos(((bone_two_length * bone_two_length) + (bone_one_length * bone_one_length) - (joint_one_to_target * joint_one_to_target)) / (2.0 * bone_two_length * bone_one_length));
+
+		if (flip_bend_direction) {
+			angle_0 = -angle_0;
+			angle_1 = -angle_1;
+		}
+
+		if (isnan(angle_0) || isnan(angle_1)) {
+			// We cannot solve for this angle! Do nothing to avoid setting the rotation (and scale) to NaN.
+		} else {
+			joint_one_bone->set_global_rotation(angle_atan - angle_0 - joint_one_bone->get_bone_angle());
+			joint_two_bone->set_rotation(-Math_PI - angle_1 - joint_two_bone->get_bone_angle() + joint_one_bone->get_bone_angle());
+		}
+	} else {
+		joint_one_bone->set_global_rotation(angle_atan - joint_one_bone->get_bone_angle());
+		joint_two_bone->set_global_rotation(angle_atan - joint_two_bone->get_bone_angle());
+	}
+
+	stack->skeleton->set_bone_local_pose_override(joint_one_bone_idx, joint_one_bone->get_transform(), stack->strength, true);
+	stack->skeleton->set_bone_local_pose_override(joint_two_bone_idx, joint_two_bone->get_transform(), stack->strength, true);
+}
+
+void SkeletonModification2DTwoBoneIK::_setup_modification(SkeletonModificationStack2D *p_stack) {
+	stack = p_stack;
+
+	if (stack) {
+		is_setup = true;
+		update_target_cache();
+		update_joint_one_bone2d_cache();
+		update_joint_two_bone2d_cache();
+	}
+}
+
+void SkeletonModification2DTwoBoneIK::_draw_editor_gizmo() {
+	if (!enabled || !is_setup) {
+		return;
+	}
+
+	Bone2D *operation_bone_one = stack->skeleton->get_bone(joint_one_bone_idx);
+	if (!operation_bone_one) {
+		return;
+	}
+	stack->skeleton->draw_set_transform(
+			stack->skeleton->get_global_transform().affine_inverse().xform(operation_bone_one->get_global_position()),
+			operation_bone_one->get_global_rotation() - stack->skeleton->get_global_rotation());
+
+	Color bone_ik_color = Color(1.0, 0.65, 0.0, 0.4);
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		bone_ik_color = EditorSettings::get_singleton()->get("editors/2d/bone_ik_color");
+	}
+#endif // TOOLS_ENABLED
+
+	if (flip_bend_direction) {
+		float angle = -(Math_PI * 0.5) + operation_bone_one->get_bone_angle();
+		stack->skeleton->draw_line(Vector2(0, 0), Vector2(Math::cos(angle), sin(angle)) * (operation_bone_one->get_length() * 0.5), bone_ik_color, 2.0);
+	} else {
+		float angle = (Math_PI * 0.5) + operation_bone_one->get_bone_angle();
+		stack->skeleton->draw_line(Vector2(0, 0), Vector2(Math::cos(angle), sin(angle)) * (operation_bone_one->get_length() * 0.5), bone_ik_color, 2.0);
+	}
+
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		if (editor_draw_min_max) {
+			if (target_maximum_distance != 0.0 || target_minimum_distance != 0.0) {
+				Vector2 target_direction = Vector2(0, 1);
+				if (target_node_cache.is_valid()) {
+					stack->skeleton->draw_set_transform(Vector2(0, 0), 0.0);
+					Node2D *target = Object::cast_to<Node2D>(ObjectDB::get_instance(target_node_cache));
+					target_direction = operation_bone_one->get_global_position().direction_to(target->get_global_position());
+				}
+
+				stack->skeleton->draw_circle(target_direction * target_minimum_distance, 8, bone_ik_color);
+				stack->skeleton->draw_circle(target_direction * target_maximum_distance, 8, bone_ik_color);
+				stack->skeleton->draw_line(target_direction * target_minimum_distance, target_direction * target_maximum_distance, bone_ik_color, 2.0);
+			}
+		}
+	}
+#endif // TOOLS_ENABLED
+}
+
+void SkeletonModification2DTwoBoneIK::update_target_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update target cache: modification is not properly setup!");
+		return;
+	}
+
+	target_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(target_node)) {
+				Node *node = stack->skeleton->get_node(target_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update target cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update target cache: node is not in the scene tree!");
+				target_node_cache = node->get_instance_id();
+			}
+		}
+	}
+}
+
+void SkeletonModification2DTwoBoneIK::update_joint_one_bone2d_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update joint one Bone2D cache: modification is not properly setup!");
+		return;
+	}
+
+	joint_one_bone2d_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(joint_one_bone2d_node)) {
+				Node *node = stack->skeleton->get_node(joint_one_bone2d_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update update joint one Bone2D cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update update joint one Bone2D cache: node is not in the scene tree!");
+				joint_one_bone2d_node_cache = node->get_instance_id();
+
+				Bone2D *bone = Object::cast_to<Bone2D>(node);
+				if (bone) {
+					joint_one_bone_idx = bone->get_index_in_skeleton();
+				} else {
+					ERR_FAIL_MSG("update joint one Bone2D cache: Nodepath to Bone2D is not a Bone2D node!");
+				}
+			}
+		}
+	}
+}
+
+void SkeletonModification2DTwoBoneIK::update_joint_two_bone2d_cache() {
+	if (!is_setup || !stack) {
+		ERR_PRINT_ONCE("Cannot update joint two Bone2D cache: modification is not properly setup!");
+		return;
+	}
+
+	joint_two_bone2d_node_cache = ObjectID();
+	if (stack->skeleton) {
+		if (stack->skeleton->is_inside_tree()) {
+			if (stack->skeleton->has_node(joint_two_bone2d_node)) {
+				Node *node = stack->skeleton->get_node(joint_two_bone2d_node);
+				ERR_FAIL_COND_MSG(!node || stack->skeleton == node,
+						"Cannot update update joint two Bone2D cache: node is this modification's skeleton or cannot be found!");
+				ERR_FAIL_COND_MSG(!node->is_inside_tree(),
+						"Cannot update update joint two Bone2D cache: node is not in scene tree!");
+				joint_two_bone2d_node_cache = node->get_instance_id();
+
+				Bone2D *bone = Object::cast_to<Bone2D>(node);
+				if (bone) {
+					joint_two_bone_idx = bone->get_index_in_skeleton();
+				} else {
+					ERR_FAIL_MSG("update joint two Bone2D cache: Nodepath to Bone2D is not a Bone2D node!");
+				}
+			}
+		}
+	}
+}
+
+void SkeletonModification2DTwoBoneIK::set_target_node(const NodePath &p_target_node) {
+	target_node = p_target_node;
+	update_target_cache();
+}
+
+NodePath SkeletonModification2DTwoBoneIK::get_target_node() const {
+	return target_node;
+}
+
+void SkeletonModification2DTwoBoneIK::set_joint_one_bone2d_node(const NodePath &p_target_node) {
+	joint_one_bone2d_node = p_target_node;
+	update_joint_one_bone2d_cache();
+	notify_property_list_changed();
+}
+
+void SkeletonModification2DTwoBoneIK::set_target_minimum_distance(float p_distance) {
+	ERR_FAIL_COND_MSG(p_distance < 0, "Target minimum distance cannot be less than zero!");
+	target_minimum_distance = p_distance;
+}
+
+float SkeletonModification2DTwoBoneIK::get_target_minimum_distance() const {
+	return target_minimum_distance;
+}
+
+void SkeletonModification2DTwoBoneIK::set_target_maximum_distance(float p_distance) {
+	ERR_FAIL_COND_MSG(p_distance < 0, "Target maximum distance cannot be less than zero!");
+	target_maximum_distance = p_distance;
+}
+
+float SkeletonModification2DTwoBoneIK::get_target_maximum_distance() const {
+	return target_maximum_distance;
+}
+
+void SkeletonModification2DTwoBoneIK::set_flip_bend_direction(bool p_flip_direction) {
+	flip_bend_direction = p_flip_direction;
+
+#ifdef TOOLS_ENABLED
+	if (stack && is_setup) {
+		stack->set_editor_gizmos_dirty(true);
+	}
+#endif // TOOLS_ENABLED
+}
+
+bool SkeletonModification2DTwoBoneIK::get_flip_bend_direction() const {
+	return flip_bend_direction;
+}
+
+NodePath SkeletonModification2DTwoBoneIK::get_joint_one_bone2d_node() const {
+	return joint_one_bone2d_node;
+}
+
+void SkeletonModification2DTwoBoneIK::set_joint_two_bone2d_node(const NodePath &p_target_node) {
+	joint_two_bone2d_node = p_target_node;
+	update_joint_two_bone2d_cache();
+	notify_property_list_changed();
+}
+
+NodePath SkeletonModification2DTwoBoneIK::get_joint_two_bone2d_node() const {
+	return joint_two_bone2d_node;
+}
+
+void SkeletonModification2DTwoBoneIK::set_joint_one_bone_idx(int p_bone_idx) {
+	ERR_FAIL_COND_MSG(p_bone_idx < 0, "Bone index is out of range: The index is too low!");
+
+	if (is_setup) {
+		if (stack->skeleton) {
+			ERR_FAIL_INDEX_MSG(p_bone_idx, stack->skeleton->get_bone_count(), "Passed-in Bone index is out of range!");
+			joint_one_bone_idx = p_bone_idx;
+			joint_one_bone2d_node_cache = stack->skeleton->get_bone(p_bone_idx)->get_instance_id();
+			joint_one_bone2d_node = stack->skeleton->get_path_to(stack->skeleton->get_bone(p_bone_idx));
+		} else {
+			WARN_PRINT("TwoBoneIK: Cannot verify the joint bone index for joint one...");
+			joint_one_bone_idx = p_bone_idx;
+		}
+	} else {
+		WARN_PRINT("TwoBoneIK: Cannot verify the joint bone index for joint one...");
+		joint_one_bone_idx = p_bone_idx;
+	}
+
+	notify_property_list_changed();
+}
+
+int SkeletonModification2DTwoBoneIK::get_joint_one_bone_idx() const {
+	return joint_one_bone_idx;
+}
+
+void SkeletonModification2DTwoBoneIK::set_joint_two_bone_idx(int p_bone_idx) {
+	ERR_FAIL_COND_MSG(p_bone_idx < 0, "Bone index is out of range: The index is too low!");
+
+	if (is_setup) {
+		if (stack->skeleton) {
+			ERR_FAIL_INDEX_MSG(p_bone_idx, stack->skeleton->get_bone_count(), "Passed-in Bone index is out of range!");
+			joint_two_bone_idx = p_bone_idx;
+			joint_two_bone2d_node_cache = stack->skeleton->get_bone(p_bone_idx)->get_instance_id();
+			joint_two_bone2d_node = stack->skeleton->get_path_to(stack->skeleton->get_bone(p_bone_idx));
+		} else {
+			WARN_PRINT("TwoBoneIK: Cannot verify the joint bone index for joint two...");
+			joint_two_bone_idx = p_bone_idx;
+		}
+	} else {
+		WARN_PRINT("TwoBoneIK: Cannot verify the joint bone index for joint two...");
+		joint_two_bone_idx = p_bone_idx;
+	}
+
+	notify_property_list_changed();
+}
+
+int SkeletonModification2DTwoBoneIK::get_joint_two_bone_idx() const {
+	return joint_two_bone_idx;
+}
+
+#ifdef TOOLS_ENABLED
+void SkeletonModification2DTwoBoneIK::set_editor_draw_min_max(bool p_draw) {
+	editor_draw_min_max = p_draw;
+}
+
+bool SkeletonModification2DTwoBoneIK::get_editor_draw_min_max() const {
+	return editor_draw_min_max;
+}
+#endif // TOOLS_ENABLED
+
+void SkeletonModification2DTwoBoneIK::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_target_node", "target_nodepath"), &SkeletonModification2DTwoBoneIK::set_target_node);
+	ClassDB::bind_method(D_METHOD("get_target_node"), &SkeletonModification2DTwoBoneIK::get_target_node);
+
+	ClassDB::bind_method(D_METHOD("set_target_minimum_distance", "minimum_distance"), &SkeletonModification2DTwoBoneIK::set_target_minimum_distance);
+	ClassDB::bind_method(D_METHOD("get_target_minimum_distance"), &SkeletonModification2DTwoBoneIK::get_target_minimum_distance);
+	ClassDB::bind_method(D_METHOD("set_target_maximum_distance", "maximum_distance"), &SkeletonModification2DTwoBoneIK::set_target_maximum_distance);
+	ClassDB::bind_method(D_METHOD("get_target_maximum_distance"), &SkeletonModification2DTwoBoneIK::get_target_maximum_distance);
+	ClassDB::bind_method(D_METHOD("set_flip_bend_direction", "flip_direction"), &SkeletonModification2DTwoBoneIK::set_flip_bend_direction);
+	ClassDB::bind_method(D_METHOD("get_flip_bend_direction"), &SkeletonModification2DTwoBoneIK::get_flip_bend_direction);
+
+	ClassDB::bind_method(D_METHOD("set_joint_one_bone2d_node", "bone2d_node"), &SkeletonModification2DTwoBoneIK::set_joint_one_bone2d_node);
+	ClassDB::bind_method(D_METHOD("get_joint_one_bone2d_node"), &SkeletonModification2DTwoBoneIK::get_joint_one_bone2d_node);
+	ClassDB::bind_method(D_METHOD("set_joint_one_bone_idx", "bone_idx"), &SkeletonModification2DTwoBoneIK::set_joint_one_bone_idx);
+	ClassDB::bind_method(D_METHOD("get_joint_one_bone_idx"), &SkeletonModification2DTwoBoneIK::get_joint_one_bone_idx);
+
+	ClassDB::bind_method(D_METHOD("set_joint_two_bone2d_node", "bone2d_node"), &SkeletonModification2DTwoBoneIK::set_joint_two_bone2d_node);
+	ClassDB::bind_method(D_METHOD("get_joint_two_bone2d_node"), &SkeletonModification2DTwoBoneIK::get_joint_two_bone2d_node);
+	ClassDB::bind_method(D_METHOD("set_joint_two_bone_idx", "bone_idx"), &SkeletonModification2DTwoBoneIK::set_joint_two_bone_idx);
+	ClassDB::bind_method(D_METHOD("get_joint_two_bone_idx"), &SkeletonModification2DTwoBoneIK::get_joint_two_bone_idx);
+
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "target_nodepath", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Node2D"), "set_target_node", "get_target_node");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "target_minimum_distance", PROPERTY_HINT_RANGE, "0, 100000000, 0.01"), "set_target_minimum_distance", "get_target_minimum_distance");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "target_maximum_distance", PROPERTY_HINT_NONE, "0, 100000000, 0.01"), "set_target_maximum_distance", "get_target_maximum_distance");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "flip_bend_direction", PROPERTY_HINT_NONE, ""), "set_flip_bend_direction", "get_flip_bend_direction");
+	ADD_GROUP("", "");
+}
+
+SkeletonModification2DTwoBoneIK::SkeletonModification2DTwoBoneIK() {
+	stack = nullptr;
+	is_setup = false;
+	enabled = true;
+	editor_draw_gizmo = true;
+}
+
+SkeletonModification2DTwoBoneIK::~SkeletonModification2DTwoBoneIK() {
+}
diff --git a/scene/resources/skeleton_modification_2d_twoboneik.h b/scene/resources/skeleton_modification_2d_twoboneik.h
new file mode 100644
index 0000000000..c7e545a488
--- /dev/null
+++ b/scene/resources/skeleton_modification_2d_twoboneik.h
@@ -0,0 +1,107 @@
+/*************************************************************************/
+/*  skeleton_modification_2d_twoboneik.h                                 */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATION2DTWOBONEIK_H
+#define SKELETONMODIFICATION2DTWOBONEIK_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+
+///////////////////////////////////////
+// SkeletonModification2DJIGGLE
+///////////////////////////////////////
+
+class SkeletonModification2DTwoBoneIK : public SkeletonModification2D {
+	GDCLASS(SkeletonModification2DTwoBoneIK, SkeletonModification2D);
+
+private:
+	NodePath target_node;
+	ObjectID target_node_cache;
+	float target_minimum_distance = 0;
+	float target_maximum_distance = 0;
+	bool flip_bend_direction = false;
+
+	NodePath joint_one_bone2d_node;
+	ObjectID joint_one_bone2d_node_cache;
+	int joint_one_bone_idx = -1;
+
+	NodePath joint_two_bone2d_node;
+	ObjectID joint_two_bone2d_node_cache;
+	int joint_two_bone_idx = -1;
+
+#ifdef TOOLS_ENABLED
+	bool editor_draw_min_max = false;
+#endif // TOOLS_ENABLED
+
+	void update_target_cache();
+	void update_joint_one_bone2d_cache();
+	void update_joint_two_bone2d_cache();
+
+protected:
+	static void _bind_methods();
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+	bool _set(const StringName &p_path, const Variant &p_value);
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+
+public:
+	void _execute(float p_delta) override;
+	void _setup_modification(SkeletonModificationStack2D *p_stack) override;
+	void _draw_editor_gizmo() override;
+
+	void set_target_node(const NodePath &p_target_node);
+	NodePath get_target_node() const;
+
+	void set_target_minimum_distance(float p_minimum_distance);
+	float get_target_minimum_distance() const;
+	void set_target_maximum_distance(float p_maximum_distance);
+	float get_target_maximum_distance() const;
+	void set_flip_bend_direction(bool p_flip_direction);
+	bool get_flip_bend_direction() const;
+
+	void set_joint_one_bone2d_node(const NodePath &p_node);
+	NodePath get_joint_one_bone2d_node() const;
+	void set_joint_one_bone_idx(int p_bone_idx);
+	int get_joint_one_bone_idx() const;
+
+	void set_joint_two_bone2d_node(const NodePath &p_node);
+	NodePath get_joint_two_bone2d_node() const;
+	void set_joint_two_bone_idx(int p_bone_idx);
+	int get_joint_two_bone_idx() const;
+
+#ifdef TOOLS_ENABLED
+	void set_editor_draw_min_max(bool p_draw);
+	bool get_editor_draw_min_max() const;
+#endif // TOOLS_ENABLED
+
+	SkeletonModification2DTwoBoneIK();
+	~SkeletonModification2DTwoBoneIK();
+};
+
+#endif // SKELETONMODIFICATION2DTWOBONEIK_H
diff --git a/scene/resources/skeleton_modification_stack_2d.cpp b/scene/resources/skeleton_modification_stack_2d.cpp
new file mode 100644
index 0000000000..d12ec4add3
--- /dev/null
+++ b/scene/resources/skeleton_modification_stack_2d.cpp
@@ -0,0 +1,267 @@
+/*************************************************************************/
+/*  skeleton_modification_stack_2d.cpp                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "skeleton_modification_stack_2d.h"
+#include "scene/2d/skeleton_2d.h"
+
+void SkeletonModificationStack2D::_get_property_list(List<PropertyInfo> *p_list) const {
+	for (int i = 0; i < modifications.size(); i++) {
+		p_list->push_back(
+				PropertyInfo(Variant::OBJECT, "modifications/" + itos(i),
+						PROPERTY_HINT_RESOURCE_TYPE,
+						"SkeletonModification2D",
+						PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_DEFERRED_SET_RESOURCE | PROPERTY_USAGE_DO_NOT_SHARE_ON_DUPLICATE));
+	}
+}
+
+bool SkeletonModificationStack2D::_set(const StringName &p_path, const Variant &p_value) {
+	String path = p_path;
+
+	if (path.begins_with("modifications/")) {
+		int mod_idx = path.get_slicec('/', 1).to_int();
+		set_modification(mod_idx, p_value);
+		return true;
+	}
+	return true;
+}
+
+bool SkeletonModificationStack2D::_get(const StringName &p_path, Variant &r_ret) const {
+	String path = p_path;
+
+	if (path.begins_with("modifications/")) {
+		int mod_idx = path.get_slicec('/', 1).to_int();
+		r_ret = get_modification(mod_idx);
+		return true;
+	}
+	return true;
+}
+
+void SkeletonModificationStack2D::setup() {
+	if (is_setup) {
+		return;
+	}
+
+	if (skeleton != nullptr) {
+		is_setup = true;
+		for (int i = 0; i < modifications.size(); i++) {
+			if (!modifications[i].is_valid()) {
+				continue;
+			}
+			modifications.get(i)->_setup_modification(this);
+		}
+
+#ifdef TOOLS_ENABLED
+		set_editor_gizmos_dirty(true);
+#endif // TOOLS_ENABLED
+
+	} else {
+		WARN_PRINT("Cannot setup SkeletonModificationStack2D: no Skeleton2D set!");
+	}
+}
+
+void SkeletonModificationStack2D::execute(float p_delta, int p_execution_mode) {
+	ERR_FAIL_COND_MSG(!is_setup || skeleton == nullptr || is_queued_for_deletion(),
+			"Modification stack is not properly setup and therefore cannot execute!");
+
+	if (!skeleton->is_inside_tree()) {
+		ERR_PRINT_ONCE("Skeleton is not inside SceneTree! Cannot execute modification!");
+		return;
+	}
+
+	if (!enabled) {
+		return;
+	}
+
+	for (int i = 0; i < modifications.size(); i++) {
+		if (!modifications[i].is_valid()) {
+			continue;
+		}
+
+		if (modifications[i]->get_execution_mode() == p_execution_mode) {
+			modifications.get(i)->_execute(p_delta);
+		}
+	}
+}
+
+void SkeletonModificationStack2D::draw_editor_gizmos() {
+	if (!is_setup) {
+		return;
+	}
+
+	if (editor_gizmo_dirty) {
+		for (int i = 0; i < modifications.size(); i++) {
+			if (!modifications[i].is_valid()) {
+				continue;
+			}
+
+			if (modifications[i]->editor_draw_gizmo) {
+				modifications.get(i)->_draw_editor_gizmo();
+			}
+		}
+		skeleton->draw_set_transform(Vector2(0, 0));
+		editor_gizmo_dirty = false;
+	}
+}
+
+void SkeletonModificationStack2D::set_editor_gizmos_dirty(bool p_dirty) {
+	if (!is_setup) {
+		return;
+	}
+
+	if (!editor_gizmo_dirty && p_dirty) {
+		editor_gizmo_dirty = p_dirty;
+		if (skeleton) {
+			skeleton->update();
+		}
+	} else {
+		editor_gizmo_dirty = p_dirty;
+	}
+}
+
+void SkeletonModificationStack2D::enable_all_modifications(bool p_enabled) {
+	for (int i = 0; i < modifications.size(); i++) {
+		if (!modifications[i].is_valid()) {
+			continue;
+		}
+		modifications.get(i)->set_enabled(p_enabled);
+	}
+}
+
+Ref<SkeletonModification2D> SkeletonModificationStack2D::get_modification(int p_mod_idx) const {
+	ERR_FAIL_INDEX_V(p_mod_idx, modifications.size(), nullptr);
+	return modifications[p_mod_idx];
+}
+
+void SkeletonModificationStack2D::add_modification(Ref<SkeletonModification2D> p_mod) {
+	p_mod->_setup_modification(this);
+	modifications.push_back(p_mod);
+
+#ifdef TOOLS_ENABLED
+	set_editor_gizmos_dirty(true);
+#endif // TOOLS_ENABLED
+}
+
+void SkeletonModificationStack2D::delete_modification(int p_mod_idx) {
+	ERR_FAIL_INDEX(p_mod_idx, modifications.size());
+	modifications.remove(p_mod_idx);
+
+#ifdef TOOLS_ENABLED
+	set_editor_gizmos_dirty(true);
+#endif // TOOLS_ENABLED
+}
+
+void SkeletonModificationStack2D::set_modification(int p_mod_idx, Ref<SkeletonModification2D> p_mod) {
+	ERR_FAIL_INDEX(p_mod_idx, modifications.size());
+
+	if (p_mod == nullptr) {
+		modifications.insert(p_mod_idx, nullptr);
+	} else {
+		p_mod->_setup_modification(this);
+		modifications.insert(p_mod_idx, p_mod);
+	}
+
+#ifdef TOOLS_ENABLED
+	set_editor_gizmos_dirty(true);
+#endif // TOOLS_ENABLED
+}
+
+void SkeletonModificationStack2D::set_modification_count(int p_count) {
+	modifications.resize(p_count);
+	notify_property_list_changed();
+
+#ifdef TOOLS_ENABLED
+	set_editor_gizmos_dirty(true);
+#endif // TOOLS_ENABLED
+}
+
+int SkeletonModificationStack2D::get_modification_count() const {
+	return modifications.size();
+}
+
+void SkeletonModificationStack2D::set_skeleton(Skeleton2D *p_skeleton) {
+	skeleton = p_skeleton;
+}
+
+Skeleton2D *SkeletonModificationStack2D::get_skeleton() const {
+	return skeleton;
+}
+
+bool SkeletonModificationStack2D::get_is_setup() const {
+	return is_setup;
+}
+
+void SkeletonModificationStack2D::set_enabled(bool p_enabled) {
+	enabled = p_enabled;
+}
+
+bool SkeletonModificationStack2D::get_enabled() const {
+	return enabled;
+}
+
+void SkeletonModificationStack2D::set_strength(float p_strength) {
+	ERR_FAIL_COND_MSG(p_strength < 0, "Strength cannot be less than zero!");
+	ERR_FAIL_COND_MSG(p_strength > 1, "Strength cannot be more than one!");
+	strength = p_strength;
+}
+
+float SkeletonModificationStack2D::get_strength() const {
+	return strength;
+}
+
+void SkeletonModificationStack2D::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("setup"), &SkeletonModificationStack2D::setup);
+	ClassDB::bind_method(D_METHOD("execute", "delta", "execution_mode"), &SkeletonModificationStack2D::execute);
+
+	ClassDB::bind_method(D_METHOD("enable_all_modifications", "enabled"), &SkeletonModificationStack2D::enable_all_modifications);
+	ClassDB::bind_method(D_METHOD("get_modification", "mod_idx"), &SkeletonModificationStack2D::get_modification);
+	ClassDB::bind_method(D_METHOD("add_modification", "modification"), &SkeletonModificationStack2D::add_modification);
+	ClassDB::bind_method(D_METHOD("delete_modification", "mod_idx"), &SkeletonModificationStack2D::delete_modification);
+	ClassDB::bind_method(D_METHOD("set_modification", "mod_idx", "modification"), &SkeletonModificationStack2D::set_modification);
+
+	ClassDB::bind_method(D_METHOD("set_modification_count"), &SkeletonModificationStack2D::set_modification_count);
+	ClassDB::bind_method(D_METHOD("get_modification_count"), &SkeletonModificationStack2D::get_modification_count);
+
+	ClassDB::bind_method(D_METHOD("get_is_setup"), &SkeletonModificationStack2D::get_is_setup);
+
+	ClassDB::bind_method(D_METHOD("set_enabled", "enabled"), &SkeletonModificationStack2D::set_enabled);
+	ClassDB::bind_method(D_METHOD("get_enabled"), &SkeletonModificationStack2D::get_enabled);
+
+	ClassDB::bind_method(D_METHOD("set_strength", "strength"), &SkeletonModificationStack2D::set_strength);
+	ClassDB::bind_method(D_METHOD("get_strength"), &SkeletonModificationStack2D::get_strength);
+
+	ClassDB::bind_method(D_METHOD("get_skeleton"), &SkeletonModificationStack2D::get_skeleton);
+
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "enabled"), "set_enabled", "get_enabled");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "strength", PROPERTY_HINT_RANGE, "0, 1, 0.001"), "set_strength", "get_strength");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "modification_count", PROPERTY_HINT_RANGE, "0, 100, 1"), "set_modification_count", "get_modification_count");
+}
+
+SkeletonModificationStack2D::SkeletonModificationStack2D() {
+}
diff --git a/scene/resources/skeleton_modification_stack_2d.h b/scene/resources/skeleton_modification_stack_2d.h
new file mode 100644
index 0000000000..58855701a1
--- /dev/null
+++ b/scene/resources/skeleton_modification_stack_2d.h
@@ -0,0 +1,99 @@
+/*************************************************************************/
+/*  skeleton_modification_stack_2d.h                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef SKELETONMODIFICATIONSTACK2D_H
+#define SKELETONMODIFICATIONSTACK2D_H
+
+#include "scene/2d/skeleton_2d.h"
+#include "scene/resources/skeleton_modification_2d.h"
+
+///////////////////////////////////////
+// SkeletonModificationStack2D
+///////////////////////////////////////
+
+class Skeleton2D;
+class SkeletonModification2D;
+class Bone2D;
+
+class SkeletonModificationStack2D : public Resource {
+	GDCLASS(SkeletonModificationStack2D, Resource);
+	friend class Skeleton2D;
+	friend class SkeletonModification2D;
+
+protected:
+	static void _bind_methods();
+	void _get_property_list(List<PropertyInfo> *p_list) const;
+	bool _set(const StringName &p_path, const Variant &p_value);
+	bool _get(const StringName &p_path, Variant &r_ret) const;
+
+public:
+	Skeleton2D *skeleton = nullptr;
+	bool is_setup = false;
+	bool enabled = false;
+	float strength = 1.0;
+
+	enum EXECUTION_MODE {
+		execution_mode_process,
+		execution_mode_physics_process
+	};
+
+	Vector<Ref<SkeletonModification2D>> modifications = Vector<Ref<SkeletonModification2D>>();
+
+	void setup();
+	void execute(float p_delta, int p_execution_mode);
+
+	bool editor_gizmo_dirty = false;
+	void draw_editor_gizmos();
+	void set_editor_gizmos_dirty(bool p_dirty);
+
+	void enable_all_modifications(bool p_enable);
+	Ref<SkeletonModification2D> get_modification(int p_mod_idx) const;
+	void add_modification(Ref<SkeletonModification2D> p_mod);
+	void delete_modification(int p_mod_idx);
+	void set_modification(int p_mod_idx, Ref<SkeletonModification2D> p_mod);
+
+	void set_modification_count(int p_count);
+	int get_modification_count() const;
+
+	void set_skeleton(Skeleton2D *p_skeleton);
+	Skeleton2D *get_skeleton() const;
+
+	bool get_is_setup() const;
+
+	void set_enabled(bool p_enabled);
+	bool get_enabled() const;
+
+	void set_strength(float p_strength);
+	float get_strength() const;
+
+	SkeletonModificationStack2D();
+};
+
+#endif // SKELETONMODIFICATION2D_H