/*************************************************************************/ /* skeleton_ik_3d.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. */ /*************************************************************************/ /** * @author AndreaCatania */ #include "skeleton_ik_3d.h" #ifndef _3D_DISABLED FabrikInverseKinematic::ChainItem *FabrikInverseKinematic::ChainItem::find_child(const BoneId p_bone_id) { for (int i = children.size() - 1; 0 <= i; --i) { if (p_bone_id == children[i].bone) { return &children.write[i]; } } return nullptr; } FabrikInverseKinematic::ChainItem *FabrikInverseKinematic::ChainItem::add_child(const BoneId p_bone_id) { const int infant_child_id = children.size(); children.resize(infant_child_id + 1); children.write[infant_child_id].bone = p_bone_id; children.write[infant_child_id].parent_item = this; return &children.write[infant_child_id]; } /// Build a chain that starts from the root to tip bool FabrikInverseKinematic::build_chain(Task *p_task, bool p_force_simple_chain) { ERR_FAIL_COND_V(-1 == p_task->root_bone, false); Chain &chain(p_task->chain); chain.tips.resize(p_task->end_effectors.size()); chain.chain_root.bone = p_task->root_bone; chain.chain_root.initial_transform = p_task->skeleton->get_bone_global_pose(chain.chain_root.bone); chain.chain_root.current_pos = chain.chain_root.initial_transform.origin; chain.middle_chain_item = nullptr; // Holds all IDs that are composing a single chain in reverse order Vector<BoneId> chain_ids; // This is used to know the chain size int sub_chain_size; // Resize only one time in order to fit all joints for performance reason chain_ids.resize(p_task->skeleton->get_bone_count()); for (int x = p_task->end_effectors.size() - 1; 0 <= x; --x) { const EndEffector *ee(&p_task->end_effectors[x]); ERR_FAIL_COND_V(p_task->root_bone >= ee->tip_bone, false); ERR_FAIL_INDEX_V(ee->tip_bone, p_task->skeleton->get_bone_count(), false); sub_chain_size = 0; // Picks all IDs that composing a single chain in reverse order (except the root) BoneId chain_sub_tip(ee->tip_bone); while (chain_sub_tip > p_task->root_bone) { chain_ids.write[sub_chain_size++] = chain_sub_tip; chain_sub_tip = p_task->skeleton->get_bone_parent(chain_sub_tip); } BoneId middle_chain_item_id = (BoneId)(sub_chain_size * 0.5); // Build chain by reading chain ids in reverse order // For each chain item id will be created a ChainItem if doesn't exists ChainItem *sub_chain(&chain.chain_root); for (int i = sub_chain_size - 1; 0 <= i; --i) { ChainItem *child_ci(sub_chain->find_child(chain_ids[i])); if (!child_ci) { child_ci = sub_chain->add_child(chain_ids[i]); child_ci->initial_transform = p_task->skeleton->get_bone_global_pose(child_ci->bone); child_ci->current_pos = child_ci->initial_transform.origin; if (child_ci->parent_item) { child_ci->length = (child_ci->current_pos - child_ci->parent_item->current_pos).length(); } } sub_chain = child_ci; if (middle_chain_item_id == i) { chain.middle_chain_item = child_ci; } } if (!middle_chain_item_id) { chain.middle_chain_item = nullptr; } // Initialize current tip chain.tips.write[x].chain_item = sub_chain; chain.tips.write[x].end_effector = ee; if (p_force_simple_chain) { // NOTE: // This is a "hack" that force to create only one tip per chain since the solver of multi tip (end effector) // is not yet created. // Remove this code when this is done break; } } return true; } void FabrikInverseKinematic::solve_simple(Task *p_task, bool p_solve_magnet, Vector3 p_origin_pos) { real_t distance_to_goal(1e4); real_t previous_distance_to_goal(0); int can_solve(p_task->max_iterations); while (distance_to_goal > p_task->min_distance && Math::abs(previous_distance_to_goal - distance_to_goal) > 0.005 && can_solve) { previous_distance_to_goal = distance_to_goal; --can_solve; solve_simple_backwards(p_task->chain, p_solve_magnet); solve_simple_forwards(p_task->chain, p_solve_magnet, p_origin_pos); distance_to_goal = (p_task->chain.tips[0].chain_item->current_pos - p_task->chain.tips[0].end_effector->goal_transform.origin).length(); } } void FabrikInverseKinematic::solve_simple_backwards(Chain &r_chain, bool p_solve_magnet) { if (p_solve_magnet && !r_chain.middle_chain_item) { return; } Vector3 goal; ChainItem *sub_chain_tip; if (p_solve_magnet) { goal = r_chain.magnet_position; sub_chain_tip = r_chain.middle_chain_item; } else { goal = r_chain.tips[0].end_effector->goal_transform.origin; sub_chain_tip = r_chain.tips[0].chain_item; } while (sub_chain_tip) { sub_chain_tip->current_pos = goal; if (sub_chain_tip->parent_item) { // Not yet in the chain root // So calculate next goal location const Vector3 look_parent((sub_chain_tip->parent_item->current_pos - sub_chain_tip->current_pos).normalized()); goal = sub_chain_tip->current_pos + (look_parent * sub_chain_tip->length); // [TODO] Constraints goes here } sub_chain_tip = sub_chain_tip->parent_item; } } void FabrikInverseKinematic::solve_simple_forwards(Chain &r_chain, bool p_solve_magnet, Vector3 p_origin_pos) { if (p_solve_magnet && !r_chain.middle_chain_item) { return; } ChainItem *sub_chain_root(&r_chain.chain_root); Vector3 origin = p_origin_pos; while (sub_chain_root) { // Reach the tip sub_chain_root->current_pos = origin; if (!sub_chain_root->children.is_empty()) { ChainItem &child(sub_chain_root->children.write[0]); // Is not tip // So calculate next origin location // Look child sub_chain_root->current_ori = (child.current_pos - sub_chain_root->current_pos).normalized(); origin = sub_chain_root->current_pos + (sub_chain_root->current_ori * child.length); // [TODO] Constraints goes here if (p_solve_magnet && sub_chain_root == r_chain.middle_chain_item) { // In case of magnet solving this is the tip sub_chain_root = nullptr; } else { sub_chain_root = &child; } } else { // Is tip sub_chain_root = nullptr; } } } FabrikInverseKinematic::Task *FabrikInverseKinematic::create_simple_task(Skeleton3D *p_sk, BoneId root_bone, BoneId tip_bone, const Transform3D &goal_transform) { FabrikInverseKinematic::EndEffector ee; ee.tip_bone = tip_bone; Task *task(memnew(Task)); task->skeleton = p_sk; task->root_bone = root_bone; task->end_effectors.push_back(ee); task->goal_global_transform = goal_transform; if (!build_chain(task)) { free_task(task); return nullptr; } return task; } void FabrikInverseKinematic::free_task(Task *p_task) { if (p_task) { memdelete(p_task); } } void FabrikInverseKinematic::set_goal(Task *p_task, const Transform3D &p_goal) { p_task->goal_global_transform = p_goal; } void FabrikInverseKinematic::make_goal(Task *p_task, const Transform3D &p_inverse_transf, real_t blending_delta) { if (blending_delta >= 0.99f) { // Update the end_effector (local transform) without blending p_task->end_effectors.write[0].goal_transform = p_inverse_transf * p_task->goal_global_transform; } else { // End effector in local transform const Transform3D end_effector_pose(p_task->skeleton->get_bone_global_pose_no_override(p_task->end_effectors[0].tip_bone)); // Update the end_effector (local transform) by blending with current pose p_task->end_effectors.write[0].goal_transform = end_effector_pose.interpolate_with(p_inverse_transf * p_task->goal_global_transform, blending_delta); } } void FabrikInverseKinematic::solve(Task *p_task, real_t blending_delta, bool override_tip_basis, bool p_use_magnet, const Vector3 &p_magnet_position) { if (blending_delta <= 0.01f) { // Before skipping, make sure we undo the global pose overrides ChainItem *ci(&p_task->chain.chain_root); while (ci) { p_task->skeleton->set_bone_global_pose_override(ci->bone, ci->initial_transform, 0.0, false); if (!ci->children.is_empty()) { ci = &ci->children.write[0]; } else { ci = nullptr; } } return; // Skip solving } // Update the initial root transform so its synced with any animation changes _update_chain(p_task->skeleton, &p_task->chain.chain_root); p_task->skeleton->set_bone_global_pose_override(p_task->chain.chain_root.bone, Transform3D(), 0.0, false); Vector3 origin_pos = p_task->skeleton->get_bone_global_pose(p_task->chain.chain_root.bone).origin; make_goal(p_task, p_task->skeleton->get_global_transform().affine_inverse(), blending_delta); if (p_use_magnet && p_task->chain.middle_chain_item) { p_task->chain.magnet_position = p_task->chain.middle_chain_item->initial_transform.origin.lerp(p_magnet_position, blending_delta); solve_simple(p_task, true, origin_pos); } solve_simple(p_task, false, origin_pos); // Assign new bone position. ChainItem *ci(&p_task->chain.chain_root); while (ci) { Transform3D new_bone_pose(ci->initial_transform); new_bone_pose.origin = ci->current_pos; if (!ci->children.is_empty()) { /// Rotate basis const Vector3 initial_ori((ci->children[0].initial_transform.origin - ci->initial_transform.origin).normalized()); const Vector3 rot_axis(initial_ori.cross(ci->current_ori).normalized()); if (rot_axis[0] != 0 && rot_axis[1] != 0 && rot_axis[2] != 0) { const real_t rot_angle(Math::acos(CLAMP(initial_ori.dot(ci->current_ori), -1, 1))); new_bone_pose.basis.rotate(rot_axis, rot_angle); } } else { // Set target orientation to tip if (override_tip_basis) { new_bone_pose.basis = p_task->chain.tips[0].end_effector->goal_transform.basis; } else { new_bone_pose.basis = new_bone_pose.basis * p_task->chain.tips[0].end_effector->goal_transform.basis; } } // IK should not affect scale, so undo any scaling new_bone_pose.basis.orthonormalize(); new_bone_pose.basis.scale(p_task->skeleton->get_bone_global_pose(ci->bone).basis.get_scale()); p_task->skeleton->set_bone_global_pose_override(ci->bone, new_bone_pose, 1.0, true); if (!ci->children.is_empty()) { ci = &ci->children.write[0]; } else { ci = nullptr; } } } void FabrikInverseKinematic::_update_chain(const Skeleton3D *p_sk, ChainItem *p_chain_item) { if (!p_chain_item) { return; } p_chain_item->initial_transform = p_sk->get_bone_global_pose_no_override(p_chain_item->bone); p_chain_item->current_pos = p_chain_item->initial_transform.origin; ChainItem *items = p_chain_item->children.ptrw(); for (int i = 0; i < p_chain_item->children.size(); i += 1) { _update_chain(p_sk, items + i); } } void SkeletonIK3D::_validate_property(PropertyInfo &property) const { if (property.name == "root_bone" || property.name == "tip_bone") { if (skeleton) { String names("--,"); for (int i = 0; i < skeleton->get_bone_count(); i++) { if (i > 0) { names += ","; } names += skeleton->get_bone_name(i); } property.hint = PROPERTY_HINT_ENUM; property.hint_string = names; } else { property.hint = PROPERTY_HINT_NONE; property.hint_string = ""; } } } void SkeletonIK3D::_bind_methods() { ClassDB::bind_method(D_METHOD("set_root_bone", "root_bone"), &SkeletonIK3D::set_root_bone); ClassDB::bind_method(D_METHOD("get_root_bone"), &SkeletonIK3D::get_root_bone); ClassDB::bind_method(D_METHOD("set_tip_bone", "tip_bone"), &SkeletonIK3D::set_tip_bone); ClassDB::bind_method(D_METHOD("get_tip_bone"), &SkeletonIK3D::get_tip_bone); ClassDB::bind_method(D_METHOD("set_interpolation", "interpolation"), &SkeletonIK3D::set_interpolation); ClassDB::bind_method(D_METHOD("get_interpolation"), &SkeletonIK3D::get_interpolation); ClassDB::bind_method(D_METHOD("set_target_transform", "target"), &SkeletonIK3D::set_target_transform); ClassDB::bind_method(D_METHOD("get_target_transform"), &SkeletonIK3D::get_target_transform); ClassDB::bind_method(D_METHOD("set_target_node", "node"), &SkeletonIK3D::set_target_node); ClassDB::bind_method(D_METHOD("get_target_node"), &SkeletonIK3D::get_target_node); ClassDB::bind_method(D_METHOD("set_override_tip_basis", "override"), &SkeletonIK3D::set_override_tip_basis); ClassDB::bind_method(D_METHOD("is_override_tip_basis"), &SkeletonIK3D::is_override_tip_basis); ClassDB::bind_method(D_METHOD("set_use_magnet", "use"), &SkeletonIK3D::set_use_magnet); ClassDB::bind_method(D_METHOD("is_using_magnet"), &SkeletonIK3D::is_using_magnet); ClassDB::bind_method(D_METHOD("set_magnet_position", "local_position"), &SkeletonIK3D::set_magnet_position); ClassDB::bind_method(D_METHOD("get_magnet_position"), &SkeletonIK3D::get_magnet_position); ClassDB::bind_method(D_METHOD("get_parent_skeleton"), &SkeletonIK3D::get_parent_skeleton); ClassDB::bind_method(D_METHOD("is_running"), &SkeletonIK3D::is_running); ClassDB::bind_method(D_METHOD("set_min_distance", "min_distance"), &SkeletonIK3D::set_min_distance); ClassDB::bind_method(D_METHOD("get_min_distance"), &SkeletonIK3D::get_min_distance); ClassDB::bind_method(D_METHOD("set_max_iterations", "iterations"), &SkeletonIK3D::set_max_iterations); ClassDB::bind_method(D_METHOD("get_max_iterations"), &SkeletonIK3D::get_max_iterations); ClassDB::bind_method(D_METHOD("start", "one_time"), &SkeletonIK3D::start, DEFVAL(false)); ClassDB::bind_method(D_METHOD("stop"), &SkeletonIK3D::stop); ADD_PROPERTY(PropertyInfo(Variant::STRING_NAME, "root_bone"), "set_root_bone", "get_root_bone"); ADD_PROPERTY(PropertyInfo(Variant::STRING_NAME, "tip_bone"), "set_tip_bone", "get_tip_bone"); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "interpolation", PROPERTY_HINT_RANGE, "0,1,0.001"), "set_interpolation", "get_interpolation"); ADD_PROPERTY(PropertyInfo(Variant::TRANSFORM3D, "target"), "set_target_transform", "get_target_transform"); ADD_PROPERTY(PropertyInfo(Variant::BOOL, "override_tip_basis"), "set_override_tip_basis", "is_override_tip_basis"); ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_magnet"), "set_use_magnet", "is_using_magnet"); ADD_PROPERTY(PropertyInfo(Variant::VECTOR3, "magnet"), "set_magnet_position", "get_magnet_position"); ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "target_node"), "set_target_node", "get_target_node"); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "min_distance"), "set_min_distance", "get_min_distance"); ADD_PROPERTY(PropertyInfo(Variant::INT, "max_iterations"), "set_max_iterations", "get_max_iterations"); } void SkeletonIK3D::_notification(int p_what) { switch (p_what) { case NOTIFICATION_ENTER_TREE: { skeleton = Object::cast_to<Skeleton3D>(get_parent()); set_process_priority(1); reload_chain(); } break; case NOTIFICATION_INTERNAL_PROCESS: { if (target_node_override) { reload_goal(); } _solve_chain(); } break; case NOTIFICATION_EXIT_TREE: { reload_chain(); } break; } } SkeletonIK3D::SkeletonIK3D() { } SkeletonIK3D::~SkeletonIK3D() { FabrikInverseKinematic::free_task(task); task = nullptr; } void SkeletonIK3D::set_root_bone(const StringName &p_root_bone) { root_bone = p_root_bone; reload_chain(); } StringName SkeletonIK3D::get_root_bone() const { return root_bone; } void SkeletonIK3D::set_tip_bone(const StringName &p_tip_bone) { tip_bone = p_tip_bone; reload_chain(); } StringName SkeletonIK3D::get_tip_bone() const { return tip_bone; } void SkeletonIK3D::set_interpolation(real_t p_interpolation) { interpolation = p_interpolation; } real_t SkeletonIK3D::get_interpolation() const { return interpolation; } void SkeletonIK3D::set_target_transform(const Transform3D &p_target) { target = p_target; reload_goal(); } const Transform3D &SkeletonIK3D::get_target_transform() const { return target; } void SkeletonIK3D::set_target_node(const NodePath &p_node) { target_node_path_override = p_node; target_node_override = nullptr; reload_goal(); } NodePath SkeletonIK3D::get_target_node() { return target_node_path_override; } void SkeletonIK3D::set_override_tip_basis(bool p_override) { override_tip_basis = p_override; } bool SkeletonIK3D::is_override_tip_basis() const { return override_tip_basis; } void SkeletonIK3D::set_use_magnet(bool p_use) { use_magnet = p_use; } bool SkeletonIK3D::is_using_magnet() const { return use_magnet; } void SkeletonIK3D::set_magnet_position(const Vector3 &p_local_position) { magnet_position = p_local_position; } const Vector3 &SkeletonIK3D::get_magnet_position() const { return magnet_position; } void SkeletonIK3D::set_min_distance(real_t p_min_distance) { min_distance = p_min_distance; } void SkeletonIK3D::set_max_iterations(int p_iterations) { max_iterations = p_iterations; } bool SkeletonIK3D::is_running() { return is_processing_internal(); } void SkeletonIK3D::start(bool p_one_time) { if (p_one_time) { set_process_internal(false); if (target_node_override) { reload_goal(); } _solve_chain(); } else { set_process_internal(true); } } void SkeletonIK3D::stop() { set_process_internal(false); if (skeleton) { skeleton->clear_bones_global_pose_override(); } } Transform3D SkeletonIK3D::_get_target_transform() { if (!target_node_override && !target_node_path_override.is_empty()) { target_node_override = Object::cast_to<Node3D>(get_node(target_node_path_override)); } if (target_node_override) { return target_node_override->get_global_transform(); } else { return target; } } void SkeletonIK3D::reload_chain() { FabrikInverseKinematic::free_task(task); task = nullptr; if (!skeleton) { return; } task = FabrikInverseKinematic::create_simple_task(skeleton, skeleton->find_bone(root_bone), skeleton->find_bone(tip_bone), _get_target_transform()); if (task) { task->max_iterations = max_iterations; task->min_distance = min_distance; } } void SkeletonIK3D::reload_goal() { if (!task) { return; } FabrikInverseKinematic::set_goal(task, _get_target_transform()); } void SkeletonIK3D::_solve_chain() { if (!task) { return; } FabrikInverseKinematic::solve(task, interpolation, override_tip_basis, use_magnet, magnet_position); } #endif // _3D_DISABLED