11 files changed, 661 insertions, 300 deletions

diff --git a/scene/animation/animation_blend_space_2d.cpp b/scene/animation/animation_blend_space_2d.cpp
index 145e7c605b..6c71be8363 100644
--- a/scene/animation/animation_blend_space_2d.cpp
+++ b/scene/animation/animation_blend_space_2d.cpp
@@ -30,6 +30,7 @@
 
 #include "animation_blend_space_2d.h"
 
+#include "animation_blend_tree.h"
 #include "core/math/geometry_2d.h"
 
 void AnimationNodeBlendSpace2D::get_parameter_list(List<PropertyInfo> *r_list) const {
@@ -531,6 +532,12 @@ double AnimationNodeBlendSpace2D::process(double p_time, bool p_seek) {
 		if (new_closest != closest && new_closest != -1) {
 			float from = 0.0;
 			if (blend_mode == BLEND_MODE_DISCRETE_CARRY && closest != -1) {
+				//for ping-pong loop
+				Ref<AnimationNodeAnimation> na_c = static_cast<Ref<AnimationNodeAnimation>>(blend_points[closest].node);
+				Ref<AnimationNodeAnimation> na_n = static_cast<Ref<AnimationNodeAnimation>>(blend_points[new_closest].node);
+				if (!na_c.is_null() && !na_n.is_null()) {
+					na_n->set_backward(na_c->is_backward());
+				}
 				//see how much animation remains
 				from = length_internal - blend_node(blend_points[closest].name, blend_points[closest].node, p_time, false, 0.0, FILTER_IGNORE, false);
 			}
diff --git a/scene/animation/animation_blend_tree.cpp b/scene/animation/animation_blend_tree.cpp
index 10a66386eb..98830bd796 100644
--- a/scene/animation/animation_blend_tree.cpp
+++ b/scene/animation/animation_blend_tree.cpp
@@ -30,6 +30,7 @@
 
 #include "animation_blend_tree.h"
 
+#include "scene/resources/animation.h"
 #include "scene/scene_string_names.h"
 
 void AnimationNodeAnimation::set_animation(const StringName &p_name) {
@@ -83,30 +84,55 @@ double AnimationNodeAnimation::process(double p_time, bool p_seek) {
 	}
 
 	Ref<Animation> anim = ap->get_animation(animation);
-
-	double step;
+	double anim_size = (double)anim->get_length();
+	double step = 0.0;
+	double prev_time = time;
+	int pingponged = 0;
+	bool current_backward = signbit(p_time);
 
 	if (p_seek) {
+		step = p_time - time;
 		time = p_time;
-		step = 0;
 	} else {
-		time = MAX(0, time + p_time);
-		step = p_time;
+		p_time *= backward ? -1.0 : 1.0;
+		if (!(time == anim_size && !current_backward) && !(time == 0 && current_backward)) {
+			time = time + p_time;
+			step = p_time;
+		}
 	}
 
-	double anim_size = anim->get_length();
-
-	if (anim->has_loop()) {
+	if (anim->get_loop_mode() == Animation::LoopMode::LOOP_PINGPONG) {
 		if (anim_size) {
-			time = Math::fposmod(time, anim_size);
+			if ((int)Math::floor(abs(time - prev_time) / anim_size) % 2 == 0) {
+				if (prev_time > 0 && time <= 0) {
+					backward = !backward;
+					pingponged = -1;
+				}
+				if (prev_time < anim_size && time >= anim_size) {
+					backward = !backward;
+					pingponged = 1;
+				}
+			}
+			time = Math::pingpong(time, anim_size);
 		}
-
-	} else if (time > anim_size) {
-		time = anim_size;
+	} else {
+		if (anim->get_loop_mode() == Animation::LoopMode::LOOP_LINEAR) {
+			if (anim_size) {
+				time = Math::fposmod(time, anim_size);
+			}
+		} else if (time < 0) {
+			time = 0;
+		} else if (time > anim_size) {
+			time = anim_size;
+		}
+		backward = false;
 	}
 
-	blend_animation(animation, time, step, p_seek, 1.0);
-
+	if (play_mode == PLAY_MODE_FORWARD) {
+		blend_animation(animation, time, step, p_seek, 1.0, pingponged);
+	} else {
+		blend_animation(animation, anim_size - time, -step, p_seek, 1.0, pingponged);
+	}
 	set_parameter(this->time, time);
 
 	return anim_size - time;
@@ -116,11 +142,34 @@ String AnimationNodeAnimation::get_caption() const {
 	return "Animation";
 }
 
+void AnimationNodeAnimation::set_play_mode(PlayMode p_play_mode) {
+	play_mode = p_play_mode;
+}
+
+AnimationNodeAnimation::PlayMode AnimationNodeAnimation::get_play_mode() const {
+	return play_mode;
+}
+
+void AnimationNodeAnimation::set_backward(bool p_backward) {
+	backward = p_backward;
+}
+
+bool AnimationNodeAnimation::is_backward() const {
+	return backward;
+}
+
 void AnimationNodeAnimation::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_animation", "name"), &AnimationNodeAnimation::set_animation);
 	ClassDB::bind_method(D_METHOD("get_animation"), &AnimationNodeAnimation::get_animation);
 
+	ClassDB::bind_method(D_METHOD("set_play_mode", "mode"), &AnimationNodeAnimation::set_play_mode);
+	ClassDB::bind_method(D_METHOD("get_play_mode"), &AnimationNodeAnimation::get_play_mode);
+
 	ADD_PROPERTY(PropertyInfo(Variant::STRING_NAME, "animation"), "set_animation", "get_animation");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "play_mode", PROPERTY_HINT_ENUM, "Forward,Backward"), "set_play_mode", "get_play_mode");
+
+	BIND_ENUM_CONSTANT(PLAY_MODE_FORWARD);
+	BIND_ENUM_CONSTANT(PLAY_MODE_BACKWARD);
 }
 
 AnimationNodeAnimation::AnimationNodeAnimation() {
@@ -533,7 +582,7 @@ AnimationNodeBlend3::AnimationNodeBlend3() {
 /////////////////////////////////
 
 void AnimationNodeTimeScale::get_parameter_list(List<PropertyInfo> *r_list) const {
-	r_list->push_back(PropertyInfo(Variant::FLOAT, scale, PROPERTY_HINT_RANGE, "0,32,0.01,or_greater"));
+	r_list->push_back(PropertyInfo(Variant::FLOAT, scale, PROPERTY_HINT_RANGE, "-32,32,0.01,or_lesser,or_greater"));
 }
 
 Variant AnimationNodeTimeScale::get_parameter_default_value(const StringName &p_parameter) const {
diff --git a/scene/animation/animation_blend_tree.h b/scene/animation/animation_blend_tree.h
index 258443a999..e55dfb58ed 100644
--- a/scene/animation/animation_blend_tree.h
+++ b/scene/animation/animation_blend_tree.h
@@ -42,12 +42,12 @@ class AnimationNodeAnimation : public AnimationRootNode {
 	uint64_t last_version = 0;
 	bool skip = false;
 
-protected:
-	void _validate_property(PropertyInfo &property) const override;
-
-	static void _bind_methods();
-
 public:
+	enum PlayMode {
+		PLAY_MODE_FORWARD,
+		PLAY_MODE_BACKWARD
+	};
+
 	void get_parameter_list(List<PropertyInfo> *r_list) const override;
 
 	static Vector<String> (*get_editable_animation_list)();
@@ -58,9 +58,25 @@ public:
 	void set_animation(const StringName &p_name);
 	StringName get_animation() const;
 
+	void set_play_mode(PlayMode p_play_mode);
+	PlayMode get_play_mode() const;
+
+	void set_backward(bool p_backward);
+	bool is_backward() const;
+
 	AnimationNodeAnimation();
+
+protected:
+	void _validate_property(PropertyInfo &property) const override;
+	static void _bind_methods();
+
+private:
+	PlayMode play_mode = PLAY_MODE_FORWARD;
+	bool backward = false;
 };
 
+VARIANT_ENUM_CAST(AnimationNodeAnimation::PlayMode)
+
 class AnimationNodeOneShot : public AnimationNode {
 	GDCLASS(AnimationNodeOneShot, AnimationNode);
 
diff --git a/scene/animation/animation_player.cpp b/scene/animation/animation_player.cpp
index 2c8c4ee788..8fd1602e8b 100644
--- a/scene/animation/animation_player.cpp
+++ b/scene/animation/animation_player.cpp
@@ -340,12 +340,13 @@ void AnimationPlayer::_ensure_node_caches(AnimationData *p_anim, Node *p_root_ov
 	}
 }
 
-void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double p_time, double p_delta, float p_interp, bool p_is_current, bool p_seeked, bool p_started) {
+void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double p_time, double p_delta, float p_interp, bool p_is_current, bool p_seeked, bool p_started, int p_pingponged) {
 	_ensure_node_caches(p_anim);
 	ERR_FAIL_COND(p_anim->node_cache.size() != p_anim->animation->get_track_count());
 
 	Animation *a = p_anim->animation.operator->();
 	bool can_call = is_inside_tree() && !Engine::get_singleton()->is_editor_hint();
+	bool backward = signbit(p_delta);
 
 	for (int i = 0; i < a->get_track_count(); i++) {
 		// If an animation changes this animation (or it animates itself)
@@ -425,8 +426,8 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 						continue; //eeh not worth it
 					}
 
-					float first_key_time = a->track_get_key_time(i, 0);
-					float transition = 1.0;
+					double first_key_time = a->track_get_key_time(i, 0);
+					double transition = 1.0;
 					int first_key = 0;
 
 					if (first_key_time == 0.0) {
@@ -434,13 +435,13 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 						if (key_count == 1) {
 							continue; //with one key we can't do anything
 						}
-						transition = a->track_get_key_transition(i, 0);
+						transition = (double)a->track_get_key_transition(i, 0);
 						first_key_time = a->track_get_key_time(i, 1);
 						first_key = 1;
 					}
 
 					if (p_time < first_key_time) {
-						float c = Math::ease(p_time / first_key_time, transition);
+						double c = Math::ease(p_time / first_key_time, transition);
 						Variant first_value = a->track_get_key_value(i, first_key);
 						Variant interp_value;
 						Variant::interpolate(pa->capture, first_value, c, interp_value);
@@ -482,7 +483,7 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 
 				} else if (p_is_current && p_delta != 0) {
 					List<int> indices;
-					a->value_track_get_key_indices(i, p_time, p_delta, &indices);
+					a->value_track_get_key_indices(i, p_time, p_delta, &indices, p_pingponged);
 
 					for (int &F : indices) {
 						Variant value = a->track_get_key_value(i, F);
@@ -541,7 +542,7 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 
 				List<int> indices;
 
-				a->method_track_get_key_indices(i, p_time, p_delta, &indices);
+				a->method_track_get_key_indices(i, p_time, p_delta, &indices, p_pingponged);
 
 				for (int &E : indices) {
 					StringName method = a->method_track_get_name(i, E);
@@ -596,7 +597,7 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 
 				TrackNodeCache::BezierAnim *ba = &E->get();
 
-				float bezier = a->bezier_track_interpolate(i, p_time);
+				real_t bezier = a->bezier_track_interpolate(i, p_time);
 				if (ba->accum_pass != accum_pass) {
 					ERR_CONTINUE(cache_update_bezier_size >= NODE_CACHE_UPDATE_MAX);
 					cache_update_bezier[cache_update_bezier_size++] = ba;
@@ -657,7 +658,7 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 				} else {
 					//find stuff to play
 					List<int> to_play;
-					a->track_get_key_indices_in_range(i, p_time, p_delta, &to_play);
+					a->track_get_key_indices_in_range(i, p_time, p_delta, &to_play, p_pingponged);
 					if (to_play.size()) {
 						int idx = to_play.back()->get();
 
@@ -685,12 +686,14 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 							nc->audio_start = p_time;
 						}
 					} else if (nc->audio_playing) {
-						bool loop = a->has_loop();
+						bool loop = a->get_loop_mode() != Animation::LoopMode::LOOP_NONE;
 
 						bool stop = false;
 
-						if (!loop && p_time < nc->audio_start) {
-							stop = true;
+						if (!loop) {
+							if ((p_time < nc->audio_start && !backward) || (p_time > nc->audio_start && backward)) {
+								stop = true;
+							}
 						} else if (nc->audio_len > 0) {
 							float len = nc->audio_start > p_time ? (a->get_length() - nc->audio_start) + p_time : p_time - nc->audio_start;
 
@@ -731,12 +734,23 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 
 					Ref<Animation> anim = player->get_animation(anim_name);
 
-					double at_anim_pos;
+					double at_anim_pos = 0.0;
 
-					if (anim->has_loop()) {
-						at_anim_pos = Math::fposmod(p_time - pos, (double)anim->get_length()); //seek to loop
-					} else {
-						at_anim_pos = MIN((double)anim->get_length(), p_time - pos); //seek to end
+					switch (anim->get_loop_mode()) {
+						case Animation::LoopMode::LOOP_NONE: {
+							at_anim_pos = MIN((double)anim->get_length(), p_time - pos); //seek to end
+						} break;
+
+						case Animation::LoopMode::LOOP_LINEAR: {
+							at_anim_pos = Math::fposmod(p_time - pos, (double)anim->get_length()); //seek to loop
+						} break;
+
+						case Animation::LoopMode::LOOP_PINGPONG: {
+							at_anim_pos = Math::pingpong(p_time - pos, (double)anim->get_length());
+						} break;
+
+						default:
+							break;
 					}
 
 					if (player->is_playing() || p_seeked) {
@@ -751,7 +765,7 @@ void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double
 				} else {
 					//find stuff to play
 					List<int> to_play;
-					a->track_get_key_indices_in_range(i, p_time, p_delta, &to_play);
+					a->track_get_key_indices_in_range(i, p_time, p_delta, &to_play, p_pingponged);
 					if (to_play.size()) {
 						int idx = to_play.back()->get();
 
@@ -781,46 +795,73 @@ void AnimationPlayer::_animation_process_data(PlaybackData &cd, double p_delta,
 	double next_pos = cd.pos + delta;
 
 	real_t len = cd.from->animation->get_length();
-	bool loop = cd.from->animation->has_loop();
+	int pingponged = 0;
+
+	switch (cd.from->animation->get_loop_mode()) {
+		case Animation::LoopMode::LOOP_NONE: {
+			if (next_pos < 0) {
+				next_pos = 0;
+			} else if (next_pos > len) {
+				next_pos = len;
+			}
 
-	if (!loop) {
-		if (next_pos < 0) {
-			next_pos = 0;
-		} else if (next_pos > len) {
-			next_pos = len;
-		}
+			bool backwards = signbit(delta); // Negative zero means playing backwards too
+			delta = next_pos - cd.pos; // Fix delta (after determination of backwards because negative zero is lost here)
 
-		bool backwards = signbit(delta); // Negative zero means playing backwards too
-		delta = next_pos - cd.pos; // Fix delta (after determination of backwards because negative zero is lost here)
+			if (&cd == &playback.current) {
+				if (!backwards && cd.pos <= len && next_pos == len) {
+					//playback finished
+					end_reached = true;
+					end_notify = cd.pos < len; // Notify only if not already at the end
+				}
 
-		if (&cd == &playback.current) {
-			if (!backwards && cd.pos <= len && next_pos == len) {
-				//playback finished
-				end_reached = true;
-				end_notify = cd.pos < len; // Notify only if not already at the end
+				if (backwards && cd.pos >= 0 && next_pos == 0) {
+					//playback finished
+					end_reached = true;
+					end_notify = cd.pos > 0; // Notify only if not already at the beginning
+				}
 			}
+		} break;
 
-			if (backwards && cd.pos >= 0 && next_pos == 0) {
-				//playback finished
-				end_reached = true;
-				end_notify = cd.pos > 0; // Notify only if not already at the beginning
+		case Animation::LoopMode::LOOP_LINEAR: {
+			double looped_next_pos = Math::fposmod(next_pos, (double)len);
+			if (looped_next_pos == 0 && next_pos != 0) {
+				// Loop multiples of the length to it, rather than 0
+				// so state at time=length is previewable in the editor
+				next_pos = len;
+			} else {
+				next_pos = looped_next_pos;
 			}
-		}
+		} break;
 
-	} else {
-		double looped_next_pos = Math::fposmod(next_pos, (double)len);
-		if (looped_next_pos == 0 && next_pos != 0) {
-			// Loop multiples of the length to it, rather than 0
-			// so state at time=length is previewable in the editor
-			next_pos = len;
-		} else {
-			next_pos = looped_next_pos;
-		}
+		case Animation::LoopMode::LOOP_PINGPONG: {
+			if ((int)Math::floor(abs(next_pos - cd.pos) / len) % 2 == 0) {
+				if (next_pos < 0 && cd.pos >= 0) {
+					cd.speed_scale *= -1.0;
+					pingponged = -1;
+				}
+				if (next_pos > len && cd.pos <= len) {
+					cd.speed_scale *= -1.0;
+					pingponged = 1;
+				}
+			}
+			double looped_next_pos = Math::pingpong(next_pos, (double)len);
+			if (looped_next_pos == 0 && next_pos != 0) {
+				// Loop multiples of the length to it, rather than 0
+				// so state at time=length is previewable in the editor
+				next_pos = len;
+			} else {
+				next_pos = looped_next_pos;
+			}
+		} break;
+
+		default:
+			break;
 	}
 
 	cd.pos = next_pos;
 
-	_animation_process_animation(cd.from, cd.pos, delta, p_blend, &cd == &playback.current, p_seeked, p_started);
+	_animation_process_animation(cd.from, cd.pos, delta, p_blend, &cd == &playback.current, p_seeked, p_started, pingponged);
 }
 
 void AnimationPlayer::_animation_process2(double p_delta, bool p_started) {
diff --git a/scene/animation/animation_player.h b/scene/animation/animation_player.h
index b693e29bdf..df041de026 100644
--- a/scene/animation/animation_player.h
+++ b/scene/animation/animation_player.h
@@ -215,7 +215,7 @@ private:
 
 	NodePath root;
 
-	void _animation_process_animation(AnimationData *p_anim, double p_time, double p_delta, float p_interp, bool p_is_current = true, bool p_seeked = false, bool p_started = false);
+	void _animation_process_animation(AnimationData *p_anim, double p_time, double p_delta, float p_interp, bool p_is_current = true, bool p_seeked = false, bool p_started = false, int p_pingponged = 0);
 
 	void _ensure_node_caches(AnimationData *p_anim, Node *p_root_override = nullptr);
 	void _animation_process_data(PlaybackData &cd, double p_delta, float p_blend, bool p_seeked, bool p_started);
diff --git a/scene/animation/animation_tree.cpp b/scene/animation/animation_tree.cpp
index 9ca8d478b1..7ea42e6df2 100644
--- a/scene/animation/animation_tree.cpp
+++ b/scene/animation/animation_tree.cpp
@@ -32,6 +32,7 @@
 
 #include "animation_blend_tree.h"
 #include "core/config/engine.h"
+#include "scene/resources/animation.h"
 #include "scene/scene_string_names.h"
 #include "servers/audio/audio_stream.h"
 
@@ -87,7 +88,7 @@ void AnimationNode::get_child_nodes(List<ChildNode> *r_child_nodes) {
 	}
 }
 
-void AnimationNode::blend_animation(const StringName &p_animation, real_t p_time, real_t p_delta, bool p_seeked, real_t p_blend) {
+void AnimationNode::blend_animation(const StringName &p_animation, real_t p_time, real_t p_delta, bool p_seeked, real_t p_blend, int p_pingponged) {
 	ERR_FAIL_COND(!state);
 	ERR_FAIL_COND(!state->player->has_animation(p_animation));
 
@@ -113,6 +114,7 @@ void AnimationNode::blend_animation(const StringName &p_animation, real_t p_time
 	anim_state.time = p_time;
 	anim_state.animation = animation;
 	anim_state.seeked = p_seeked;
+	anim_state.pingponged = p_pingponged;
 
 	state->animation_states.push_back(anim_state);
 }
@@ -418,7 +420,7 @@ void AnimationNode::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("_set_filters", "filters"), &AnimationNode::_set_filters);
 	ClassDB::bind_method(D_METHOD("_get_filters"), &AnimationNode::_get_filters);
 
-	ClassDB::bind_method(D_METHOD("blend_animation", "animation", "time", "delta", "seeked", "blend"), &AnimationNode::blend_animation);
+	ClassDB::bind_method(D_METHOD("blend_animation", "animation", "time", "delta", "seeked", "blend", "pingponged"), &AnimationNode::blend_animation, DEFVAL(0));
 	ClassDB::bind_method(D_METHOD("blend_node", "name", "node", "time", "seek", "blend", "filter", "optimize"), &AnimationNode::blend_node, DEFVAL(FILTER_IGNORE), DEFVAL(true));
 	ClassDB::bind_method(D_METHOD("blend_input", "input_index", "time", "seek", "blend", "filter", "optimize"), &AnimationNode::blend_input, DEFVAL(FILTER_IGNORE), DEFVAL(true));
 
@@ -824,6 +826,8 @@ void AnimationTree::_process_graph(real_t p_delta) {
 			double delta = as.delta;
 			real_t weight = as.blend;
 			bool seeked = as.seeked;
+			int pingponged = as.pingponged;
+			bool backward = signbit(delta);
 
 			for (int i = 0; i < a->get_track_count(); i++) {
 				NodePath path = a->track_get_path(i);
@@ -862,12 +866,38 @@ void AnimationTree::_process_graph(real_t p_delta) {
 								t->scale = Vector3(1, 1, 1);
 							}
 
-							real_t prev_time = time - delta;
-							if (prev_time < 0) {
-								if (!a->has_loop()) {
-									prev_time = 0;
-								} else {
-									prev_time = a->get_length() + prev_time;
+							double prev_time = time - delta;
+							if (!backward) {
+								if (prev_time < 0) {
+									switch (a->get_loop_mode()) {
+										case Animation::LoopMode::LOOP_NONE: {
+											prev_time = 0;
+										} break;
+										case Animation::LoopMode::LOOP_LINEAR: {
+											prev_time = Math::fposmod(prev_time, (double)a->get_length());
+										} break;
+										case Animation::LoopMode::LOOP_PINGPONG: {
+											prev_time = Math::pingpong(prev_time, (double)a->get_length());
+										} break;
+										default:
+											break;
+									}
+								}
+							} else {
+								if (prev_time > a->get_length()) {
+									switch (a->get_loop_mode()) {
+										case Animation::LoopMode::LOOP_NONE: {
+											prev_time = (double)a->get_length();
+										} break;
+										case Animation::LoopMode::LOOP_LINEAR: {
+											prev_time = Math::fposmod(prev_time, (double)a->get_length());
+										} break;
+										case Animation::LoopMode::LOOP_PINGPONG: {
+											prev_time = Math::pingpong(prev_time, (double)a->get_length());
+										} break;
+										default:
+											break;
+									}
 								}
 							}
 
@@ -875,20 +905,38 @@ void AnimationTree::_process_graph(real_t p_delta) {
 							Quaternion rot[2];
 							Vector3 scale[2];
 
-							if (prev_time > time) {
-								Error err = a->transform_track_interpolate(i, prev_time, &loc[0], &rot[0], &scale[0]);
-								if (err != OK) {
-									continue;
+							if (!backward) {
+								if (prev_time > time) {
+									Error err = a->transform_track_interpolate(i, prev_time, &loc[0], &rot[0], &scale[0]);
+									if (err != OK) {
+										continue;
+									}
+
+									a->transform_track_interpolate(i, (double)a->get_length(), &loc[1], &rot[1], &scale[1]);
+
+									t->loc += (loc[1] - loc[0]) * blend;
+									t->scale += (scale[1] - scale[0]) * blend;
+									Quaternion q = Quaternion().slerp(rot[0].normalized().inverse() * rot[1].normalized(), blend).normalized();
+									t->rot = (t->rot * q).normalized();
+
+									prev_time = 0;
 								}
+							} else {
+								if (prev_time < time) {
+									Error err = a->transform_track_interpolate(i, prev_time, &loc[0], &rot[0], &scale[0]);
+									if (err != OK) {
+										continue;
+									}
 
-								a->transform_track_interpolate(i, a->get_length(), &loc[1], &rot[1], &scale[1]);
+									a->transform_track_interpolate(i, 0, &loc[1], &rot[1], &scale[1]);
 
-								t->loc += (loc[1] - loc[0]) * blend;
-								t->scale += (scale[1] - scale[0]) * blend;
-								Quaternion q = Quaternion().slerp(rot[0].normalized().inverse() * rot[1].normalized(), blend).normalized();
-								t->rot = (t->rot * q).normalized();
+									t->loc += (loc[1] - loc[0]) * blend;
+									t->scale += (scale[1] - scale[0]) * blend;
+									Quaternion q = Quaternion().slerp(rot[0].normalized().inverse() * rot[1].normalized(), blend).normalized();
+									t->rot = (t->rot * q).normalized();
 
-								prev_time = 0;
+									prev_time = 0;
+								}
 							}
 
 							Error err = a->transform_track_interpolate(i, prev_time, &loc[0], &rot[0], &scale[0]);
@@ -903,8 +951,7 @@ void AnimationTree::_process_graph(real_t p_delta) {
 							Quaternion q = Quaternion().slerp(rot[0].normalized().inverse() * rot[1].normalized(), blend).normalized();
 							t->rot = (t->rot * q).normalized();
 
-							prev_time = 0;
-
+							prev_time = !backward ? 0 : (double)a->get_length();
 						} else {
 							Vector3 loc;
 							Quaternion rot;
@@ -960,7 +1007,7 @@ void AnimationTree::_process_graph(real_t p_delta) {
 
 						} else {
 							List<int> indices;
-							a->value_track_get_key_indices(i, time, delta, &indices);
+							a->value_track_get_key_indices(i, time, delta, &indices, pingponged);
 
 							for (int &F : indices) {
 								Variant value = a->track_get_key_value(i, F);
@@ -977,7 +1024,7 @@ void AnimationTree::_process_graph(real_t p_delta) {
 
 						List<int> indices;
 
-						a->method_track_get_key_indices(i, time, delta, &indices);
+						a->method_track_get_key_indices(i, time, delta, &indices, pingponged);
 
 						for (int &F : indices) {
 							StringName method = a->method_track_get_name(i, F);
@@ -1060,7 +1107,7 @@ void AnimationTree::_process_graph(real_t p_delta) {
 						} else {
 							//find stuff to play
 							List<int> to_play;
-							a->track_get_key_indices_in_range(i, time, delta, &to_play);
+							a->track_get_key_indices_in_range(i, time, delta, &to_play, pingponged);
 							if (to_play.size()) {
 								int idx = to_play.back()->get();
 
@@ -1088,12 +1135,20 @@ void AnimationTree::_process_graph(real_t p_delta) {
 									t->start = time;
 								}
 							} else if (t->playing) {
-								bool loop = a->has_loop();
+								bool loop = a->get_loop_mode() != Animation::LoopMode::LOOP_NONE;
 
 								bool stop = false;
 
-								if (!loop && time < t->start) {
-									stop = true;
+								if (!loop) {
+									if (delta > 0) {
+										if (time < t->start) {
+											stop = true;
+										}
+									} else if (delta < 0) {
+										if (time > t->start) {
+											stop = true;
+										}
+									}
 								} else if (t->len > 0) {
 									real_t len = t->start > time ? (a->get_length() - t->start) + time : time - t->start;
 
@@ -1127,7 +1182,7 @@ void AnimationTree::_process_graph(real_t p_delta) {
 							continue;
 						}
 
-						if (delta == 0 || seeked) {
+						if (seeked) {
 							//seek
 							int idx = a->track_find_key(i, time);
 							if (idx < 0) {
@@ -1143,12 +1198,20 @@ void AnimationTree::_process_graph(real_t p_delta) {
 
 							Ref<Animation> anim = player2->get_animation(anim_name);
 
-							real_t at_anim_pos;
-
-							if (anim->has_loop()) {
-								at_anim_pos = Math::fposmod(time - pos, (double)anim->get_length()); //seek to loop
-							} else {
-								at_anim_pos = MAX(anim->get_length(), time - pos); //seek to end
+							real_t at_anim_pos = 0.0;
+
+							switch (anim->get_loop_mode()) {
+								case Animation::LoopMode::LOOP_NONE: {
+									at_anim_pos = MAX((double)anim->get_length(), time - pos); //seek to end
+								} break;
+								case Animation::LoopMode::LOOP_LINEAR: {
+									at_anim_pos = Math::fposmod(time - pos, (double)anim->get_length()); //seek to loop
+								} break;
+								case Animation::LoopMode::LOOP_PINGPONG: {
+									at_anim_pos = Math::pingpong(time - pos, (double)a->get_length());
+								} break;
+								default:
+									break;
 							}
 
 							if (player2->is_playing() || seeked) {
@@ -1163,7 +1226,7 @@ void AnimationTree::_process_graph(real_t p_delta) {
 						} else {
 							//find stuff to play
 							List<int> to_play;
-							a->track_get_key_indices_in_range(i, time, delta, &to_play);
+							a->track_get_key_indices_in_range(i, time, delta, &to_play, pingponged);
 							if (to_play.size()) {
 								int idx = to_play.back()->get();
 
diff --git a/scene/animation/animation_tree.h b/scene/animation/animation_tree.h
index 1e0267682e..7482de7ee1 100644
--- a/scene/animation/animation_tree.h
+++ b/scene/animation/animation_tree.h
@@ -68,6 +68,7 @@ public:
 		const Vector<real_t> *track_blends = nullptr;
 		real_t blend = 0.0;
 		bool seeked = false;
+		int pingponged = 0;
 	};
 
 	struct State {
@@ -101,9 +102,10 @@ public:
 	real_t _blend_node(const StringName &p_subpath, const Vector<StringName> &p_connections, AnimationNode *p_new_parent, Ref<AnimationNode> p_node, real_t p_time, bool p_seek, real_t p_blend, FilterAction p_filter = FILTER_IGNORE, bool p_optimize = true, real_t *r_max = nullptr);
 
 protected:
-	void blend_animation(const StringName &p_animation, real_t p_time, real_t p_delta, bool p_seeked, real_t p_blend);
+	void blend_animation(const StringName &p_animation, real_t p_time, real_t p_delta, bool p_seeked, real_t p_blend, int p_pingponged = 0);
 	real_t blend_node(const StringName &p_sub_path, Ref<AnimationNode> p_node, real_t p_time, bool p_seek, real_t p_blend, FilterAction p_filter = FILTER_IGNORE, bool p_optimize = true);
 	real_t blend_input(int p_input, real_t p_time, bool p_seek, real_t p_blend, FilterAction p_filter = FILTER_IGNORE, bool p_optimize = true);
+
 	void make_invalid(const String &p_reason);
 
 	static void _bind_methods();
diff --git a/scene/resources/animation.cpp b/scene/resources/animation.cpp
index b4eec2530b..4382674470 100644
--- a/scene/resources/animation.cpp
+++ b/scene/resources/animation.cpp
@@ -309,8 +309,8 @@ bool Animation::_get(const StringName &p_name, Variant &r_ret) const {
 
 	if (name == "length") {
 		r_ret = length;
-	} else if (name == "loop") {
-		r_ret = loop;
+	} else if (name == "loop_mode") {
+		r_ret = loop_mode;
 	} else if (name == "step") {
 		r_ret = step;
 	} else if (name.begins_with("tracks/")) {
@@ -1413,7 +1413,7 @@ void Animation::track_set_key_transition(int p_track, int p_key_idx, real_t p_tr
 }
 
 template <class K>
-int Animation::_find(const Vector<K> &p_keys, double p_time) const {
+int Animation::_find(const Vector<K> &p_keys, double p_time, bool p_backward) const {
 	int len = p_keys.size();
 	if (len == 0) {
 		return -2;
@@ -1443,8 +1443,14 @@ int Animation::_find(const Vector<K> &p_keys, double p_time) const {
 		}
 	}
 
-	if (keys[middle].time > p_time) {
-		middle--;
+	if (!p_backward) {
+		if (keys[middle].time > p_time) {
+			middle--;
+		}
+	} else {
+		if (keys[middle].time < p_time) {
+			middle++;
+		}
 	}
 
 	return middle;
@@ -1585,7 +1591,7 @@ real_t Animation::_cubic_interpolate(const real_t &p_pre_a, const real_t &p_a, c
 }
 
 template <class T>
-T Animation::_interpolate(const Vector<TKey<T>> &p_keys, double p_time, InterpolationType p_interp, bool p_loop_wrap, bool *p_ok) const {
+T Animation::_interpolate(const Vector<TKey<T>> &p_keys, double p_time, InterpolationType p_interp, bool p_loop_wrap, bool *p_ok, bool p_backward) const {
 	int len = _find(p_keys, length) + 1; // try to find last key (there may be more past the end)
 
 	if (len <= 0) {
@@ -1603,7 +1609,7 @@ T Animation::_interpolate(const Vector<TKey<T>> &p_keys, double p_time, Interpol
 		return p_keys[0].value;
 	}
 
-	int idx = _find(p_keys, p_time);
+	int idx = _find(p_keys, p_time, p_backward);
 
 	ERR_FAIL_COND_V(idx == -2, T());
 
@@ -1612,24 +1618,42 @@ T Animation::_interpolate(const Vector<TKey<T>> &p_keys, double p_time, Interpol
 	real_t c = 0.0;
 	// prepare for all cases of interpolation
 
-	if (loop && p_loop_wrap) {
+	if ((loop_mode == LOOP_LINEAR || loop_mode == LOOP_PINGPONG) && p_loop_wrap) {
 		// loop
-		if (idx >= 0) {
-			if ((idx + 1) < len) {
-				next = idx + 1;
-				real_t delta = p_keys[next].time - p_keys[idx].time;
-				real_t from = p_time - p_keys[idx].time;
-
-				if (Math::is_zero_approx(delta)) {
-					c = 0;
+		if (!p_backward) {
+			// no backward
+			if (idx >= 0) {
+				if (idx < len - 1) {
+					next = idx + 1;
+					real_t delta = p_keys[next].time - p_keys[idx].time;
+					real_t from = p_time - p_keys[idx].time;
+
+					if (Math::is_zero_approx(delta)) {
+						c = 0;
+					} else {
+						c = from / delta;
+					}
 				} else {
-					c = from / delta;
+					next = 0;
+					real_t delta = (length - p_keys[idx].time) + p_keys[next].time;
+					real_t from = p_time - p_keys[idx].time;
+
+					if (Math::is_zero_approx(delta)) {
+						c = 0;
+					} else {
+						c = from / delta;
+					}
 				}
-
 			} else {
+				// on loop, behind first key
+				idx = len - 1;
 				next = 0;
-				real_t delta = (length - p_keys[idx].time) + p_keys[next].time;
-				real_t from = p_time - p_keys[idx].time;
+				real_t endtime = (length - p_keys[idx].time);
+				if (endtime < 0) { // may be keys past the end
+					endtime = 0;
+				}
+				real_t delta = endtime + p_keys[next].time;
+				real_t from = endtime + p_time;
 
 				if (Math::is_zero_approx(delta)) {
 					c = 0;
@@ -1637,49 +1661,81 @@ T Animation::_interpolate(const Vector<TKey<T>> &p_keys, double p_time, Interpol
 					c = from / delta;
 				}
 			}
-
 		} else {
-			// on loop, behind first key
-			idx = len - 1;
-			next = 0;
-			real_t endtime = (length - p_keys[idx].time);
-			if (endtime < 0) { // may be keys past the end
-				endtime = 0;
-			}
-			real_t delta = endtime + p_keys[next].time;
-			real_t from = endtime + p_time;
-
-			if (Math::is_zero_approx(delta)) {
-				c = 0;
+			// backward
+			if (idx <= len - 1) {
+				if (idx > 0) {
+					next = idx - 1;
+					real_t delta = (length - p_keys[next].time) - (length - p_keys[idx].time);
+					real_t from = (length - p_time) - (length - p_keys[idx].time);
+
+					if (Math::is_zero_approx(delta))
+						c = 0;
+					else
+						c = from / delta;
+				} else {
+					next = len - 1;
+					real_t delta = p_keys[idx].time + (length - p_keys[next].time);
+					real_t from = (length - p_time) - (length - p_keys[idx].time);
+
+					if (Math::is_zero_approx(delta))
+						c = 0;
+					else
+						c = from / delta;
+				}
 			} else {
-				c = from / delta;
+				// on loop, in front of last key
+				idx = 0;
+				next = len - 1;
+				real_t endtime = p_keys[idx].time;
+				if (endtime > length) // may be keys past the end
+					endtime = length;
+				real_t delta = p_keys[next].time - endtime;
+				real_t from = p_time - endtime;
+
+				if (Math::is_zero_approx(delta))
+					c = 0;
+				else
+					c = from / delta;
 			}
 		}
-
 	} else { // no loop
-
-		if (idx >= 0) {
-			if ((idx + 1) < len) {
-				next = idx + 1;
-				real_t delta = p_keys[next].time - p_keys[idx].time;
-				real_t from = p_time - p_keys[idx].time;
-
-				if (Math::is_zero_approx(delta)) {
-					c = 0;
+		if (!p_backward) {
+			if (idx >= 0) {
+				if (idx < len - 1) {
+					next = idx + 1;
+					real_t delta = p_keys[next].time - p_keys[idx].time;
+					real_t from = p_time - p_keys[idx].time;
+
+					if (Math::is_zero_approx(delta)) {
+						c = 0;
+					} else {
+						c = from / delta;
+					}
 				} else {
-					c = from / delta;
+					next = idx;
 				}
-
 			} else {
-				next = idx;
+				idx = next = 0;
 			}
-
 		} else {
-			// only allow extending first key to anim start if looping
-			if (loop) {
-				idx = next = 0;
+			if (idx <= len - 1) {
+				if (idx > 0) {
+					next = idx - 1;
+					real_t delta = (length - p_keys[next].time) - (length - p_keys[idx].time);
+					real_t from = (length - p_time) - (length - p_keys[idx].time);
+
+					if (Math::is_zero_approx(delta)) {
+						c = 0;
+					} else {
+						c = from / delta;
+					}
+
+				} else {
+					next = idx;
+				}
 			} else {
-				result = false;
+				idx = next = len - 1;
 			}
 		}
 	}
@@ -1729,7 +1785,7 @@ T Animation::_interpolate(const Vector<TKey<T>> &p_keys, double p_time, Interpol
 	// do a barrel roll
 }
 
-Error Animation::transform_track_interpolate(int p_track, double p_time, Vector3 *r_loc, Quaternion *r_rot, Vector3 *r_scale) const {
+Error Animation::transform_track_interpolate(int p_track, double p_time, Vector3 *r_loc, Quaternion *r_rot, Vector3 *r_scale, bool p_backward) const {
 	ERR_FAIL_INDEX_V(p_track, tracks.size(), ERR_INVALID_PARAMETER);
 	Track *t = tracks[p_track];
 	ERR_FAIL_COND_V(t->type != TYPE_TRANSFORM3D, ERR_INVALID_PARAMETER);
@@ -1738,7 +1794,7 @@ Error Animation::transform_track_interpolate(int p_track, double p_time, Vector3
 
 	bool ok = false;
 
-	TransformKey tk = _interpolate(tt->transforms, p_time, tt->interpolation, tt->loop_wrap, &ok);
+	TransformKey tk = _interpolate(tt->transforms, p_time, tt->interpolation, tt->loop_wrap, &ok, p_backward);
 
 	if (!ok) {
 		return ERR_UNAVAILABLE;
@@ -1813,7 +1869,7 @@ void Animation::_value_track_get_key_indices_in_range(const ValueTrack *vt, doub
 	}
 }
 
-void Animation::value_track_get_key_indices(int p_track, double p_time, double p_delta, List<int> *p_indices) const {
+void Animation::value_track_get_key_indices(int p_track, double p_time, double p_delta, List<int> *p_indices, int p_pingponged) const {
 	ERR_FAIL_INDEX(p_track, tracks.size());
 	Track *t = tracks[p_track];
 	ERR_FAIL_COND(t->type != TYPE_VALUE);
@@ -1827,30 +1883,50 @@ void Animation::value_track_get_key_indices(int p_track, double p_time, double p
 		SWAP(from_time, to_time);
 	}
 
-	if (loop) {
-		from_time = Math::fposmod(from_time, length);
-		to_time = Math::fposmod(to_time, length);
+	switch (loop_mode) {
+		case LOOP_NONE: {
+			if (from_time < 0) {
+				from_time = 0;
+			}
+			if (from_time > length) {
+				from_time = length;
+			}
 
-		if (from_time > to_time) {
-			// handle loop by splitting
-			_value_track_get_key_indices_in_range(vt, from_time, length, p_indices);
-			_value_track_get_key_indices_in_range(vt, 0, to_time, p_indices);
-			return;
-		}
-	} else {
-		if (from_time < 0) {
-			from_time = 0;
-		}
-		if (from_time > length) {
-			from_time = length;
-		}
+			if (to_time < 0) {
+				to_time = 0;
+			}
+			if (to_time > length) {
+				to_time = length;
+			}
+		} break;
+		case LOOP_LINEAR: {
+			from_time = Math::fposmod(from_time, length);
+			to_time = Math::fposmod(to_time, length);
 
-		if (to_time < 0) {
-			to_time = 0;
-		}
-		if (to_time > length) {
-			to_time = length;
-		}
+			if (from_time > to_time) {
+				// handle loop by splitting
+				_value_track_get_key_indices_in_range(vt, from_time, length, p_indices);
+				_value_track_get_key_indices_in_range(vt, 0, to_time, p_indices);
+				return;
+			}
+		} break;
+		case LOOP_PINGPONG: {
+			from_time = Math::pingpong(from_time, length);
+			to_time = Math::pingpong(to_time, length);
+
+			if (p_pingponged == -1) {
+				// handle loop by splitting
+				_value_track_get_key_indices_in_range(vt, 0, from_time, p_indices);
+				_value_track_get_key_indices_in_range(vt, 0, to_time, p_indices);
+				return;
+			}
+			if (p_pingponged == 1) {
+				// handle loop by splitting
+				_value_track_get_key_indices_in_range(vt, from_time, length, p_indices);
+				_value_track_get_key_indices_in_range(vt, to_time, length, p_indices);
+				return;
+			}
+		} break;
 	}
 
 	_value_track_get_key_indices_in_range(vt, from_time, to_time, p_indices);
@@ -1909,7 +1985,7 @@ void Animation::_track_get_key_indices_in_range(const Vector<T> &p_array, double
 	}
 }
 
-void Animation::track_get_key_indices_in_range(int p_track, double p_time, double p_delta, List<int> *p_indices) const {
+void Animation::track_get_key_indices_in_range(int p_track, double p_time, double p_delta, List<int> *p_indices, int p_pingponged) const {
 	ERR_FAIL_INDEX(p_track, tracks.size());
 	const Track *t = tracks[p_track];
 
@@ -1920,104 +1996,176 @@ void Animation::track_get_key_indices_in_range(int p_track, double p_time, doubl
 		SWAP(from_time, to_time);
 	}
 
-	if (loop) {
-		if (from_time > length || from_time < 0) {
-			from_time = Math::fposmod(from_time, length);
-		}
+	switch (loop_mode) {
+		case LOOP_NONE: {
+			if (from_time < 0) {
+				from_time = 0;
+			}
+			if (from_time > length) {
+				from_time = length;
+			}
 
-		if (to_time > length || to_time < 0) {
-			to_time = Math::fposmod(to_time, length);
-		}
+			if (to_time < 0) {
+				to_time = 0;
+			}
+			if (to_time > length) {
+				to_time = length;
+			}
+		} break;
+		case LOOP_LINEAR: {
+			if (from_time > length || from_time < 0) {
+				from_time = Math::fposmod(from_time, length);
+			}
+			if (to_time > length || to_time < 0) {
+				to_time = Math::fposmod(to_time, length);
+			}
 
-		if (from_time > to_time) {
-			// handle loop by splitting
-
-			switch (t->type) {
-				case TYPE_TRANSFORM3D: {
-					const TransformTrack *tt = static_cast<const TransformTrack *>(t);
-					_track_get_key_indices_in_range(tt->transforms, from_time, length, p_indices);
-					_track_get_key_indices_in_range(tt->transforms, 0, to_time, p_indices);
-
-				} break;
-				case TYPE_VALUE: {
-					const ValueTrack *vt = static_cast<const ValueTrack *>(t);
-					_track_get_key_indices_in_range(vt->values, from_time, length, p_indices);
-					_track_get_key_indices_in_range(vt->values, 0, to_time, p_indices);
-
-				} break;
-				case TYPE_METHOD: {
-					const MethodTrack *mt = static_cast<const MethodTrack *>(t);
-					_track_get_key_indices_in_range(mt->methods, from_time, length, p_indices);
-					_track_get_key_indices_in_range(mt->methods, 0, to_time, p_indices);
-
-				} break;
-				case TYPE_BEZIER: {
-					const BezierTrack *bz = static_cast<const BezierTrack *>(t);
-					_track_get_key_indices_in_range(bz->values, from_time, length, p_indices);
-					_track_get_key_indices_in_range(bz->values, 0, to_time, p_indices);
-
-				} break;
-				case TYPE_AUDIO: {
-					const AudioTrack *ad = static_cast<const AudioTrack *>(t);
-					_track_get_key_indices_in_range(ad->values, from_time, length, p_indices);
-					_track_get_key_indices_in_range(ad->values, 0, to_time, p_indices);
-
-				} break;
-				case TYPE_ANIMATION: {
-					const AnimationTrack *an = static_cast<const AnimationTrack *>(t);
-					_track_get_key_indices_in_range(an->values, from_time, length, p_indices);
-					_track_get_key_indices_in_range(an->values, 0, to_time, p_indices);
-
-				} break;
+			if (from_time > to_time) {
+				// handle loop by splitting
+				switch (t->type) {
+					case TYPE_TRANSFORM3D: {
+						const TransformTrack *tt = static_cast<const TransformTrack *>(t);
+						_track_get_key_indices_in_range(tt->transforms, from_time, length, p_indices);
+						_track_get_key_indices_in_range(tt->transforms, 0, to_time, p_indices);
+					} break;
+					case TYPE_VALUE: {
+						const ValueTrack *vt = static_cast<const ValueTrack *>(t);
+						_track_get_key_indices_in_range(vt->values, from_time, length, p_indices);
+						_track_get_key_indices_in_range(vt->values, 0, to_time, p_indices);
+					} break;
+					case TYPE_METHOD: {
+						const MethodTrack *mt = static_cast<const MethodTrack *>(t);
+						_track_get_key_indices_in_range(mt->methods, from_time, length, p_indices);
+						_track_get_key_indices_in_range(mt->methods, 0, to_time, p_indices);
+					} break;
+					case TYPE_BEZIER: {
+						const BezierTrack *bz = static_cast<const BezierTrack *>(t);
+						_track_get_key_indices_in_range(bz->values, from_time, length, p_indices);
+						_track_get_key_indices_in_range(bz->values, 0, to_time, p_indices);
+					} break;
+					case TYPE_AUDIO: {
+						const AudioTrack *ad = static_cast<const AudioTrack *>(t);
+						_track_get_key_indices_in_range(ad->values, from_time, length, p_indices);
+						_track_get_key_indices_in_range(ad->values, 0, to_time, p_indices);
+					} break;
+					case TYPE_ANIMATION: {
+						const AnimationTrack *an = static_cast<const AnimationTrack *>(t);
+						_track_get_key_indices_in_range(an->values, from_time, length, p_indices);
+						_track_get_key_indices_in_range(an->values, 0, to_time, p_indices);
+					} break;
+				}
+				return;
+			}
+		} break;
+		case LOOP_PINGPONG: {
+			if (from_time > length || from_time < 0) {
+				from_time = Math::pingpong(from_time, length);
+			}
+			if (to_time > length || to_time < 0) {
+				to_time = Math::pingpong(to_time, length);
 			}
-			return;
-		}
-	} else {
-		if (from_time < 0) {
-			from_time = 0;
-		}
-		if (from_time > length) {
-			from_time = length;
-		}
 
-		if (to_time < 0) {
-			to_time = 0;
-		}
-		if (to_time > length) {
-			to_time = length;
-		}
+			if ((int)Math::floor(abs(p_delta) / length) % 2 == 0) {
+				if (p_pingponged == -1) {
+					// handle loop by splitting
+					switch (t->type) {
+						case TYPE_TRANSFORM3D: {
+							const TransformTrack *tt = static_cast<const TransformTrack *>(t);
+							_track_get_key_indices_in_range(tt->transforms, 0, from_time, p_indices);
+							_track_get_key_indices_in_range(tt->transforms, 0, to_time, p_indices);
+						} break;
+						case TYPE_VALUE: {
+							const ValueTrack *vt = static_cast<const ValueTrack *>(t);
+							_track_get_key_indices_in_range(vt->values, 0, from_time, p_indices);
+							_track_get_key_indices_in_range(vt->values, 0, to_time, p_indices);
+						} break;
+						case TYPE_METHOD: {
+							const MethodTrack *mt = static_cast<const MethodTrack *>(t);
+							_track_get_key_indices_in_range(mt->methods, 0, from_time, p_indices);
+							_track_get_key_indices_in_range(mt->methods, 0, to_time, p_indices);
+						} break;
+						case TYPE_BEZIER: {
+							const BezierTrack *bz = static_cast<const BezierTrack *>(t);
+							_track_get_key_indices_in_range(bz->values, 0, from_time, p_indices);
+							_track_get_key_indices_in_range(bz->values, 0, to_time, p_indices);
+						} break;
+						case TYPE_AUDIO: {
+							const AudioTrack *ad = static_cast<const AudioTrack *>(t);
+							_track_get_key_indices_in_range(ad->values, 0, from_time, p_indices);
+							_track_get_key_indices_in_range(ad->values, 0, to_time, p_indices);
+						} break;
+						case TYPE_ANIMATION: {
+							const AnimationTrack *an = static_cast<const AnimationTrack *>(t);
+							_track_get_key_indices_in_range(an->values, 0, from_time, p_indices);
+							_track_get_key_indices_in_range(an->values, 0, to_time, p_indices);
+						} break;
+					}
+					return;
+				}
+				if (p_pingponged == 1) {
+					// handle loop by splitting
+					switch (t->type) {
+						case TYPE_TRANSFORM3D: {
+							const TransformTrack *tt = static_cast<const TransformTrack *>(t);
+							_track_get_key_indices_in_range(tt->transforms, from_time, length, p_indices);
+							_track_get_key_indices_in_range(tt->transforms, to_time, length, p_indices);
+						} break;
+						case TYPE_VALUE: {
+							const ValueTrack *vt = static_cast<const ValueTrack *>(t);
+							_track_get_key_indices_in_range(vt->values, from_time, length, p_indices);
+							_track_get_key_indices_in_range(vt->values, to_time, length, p_indices);
+						} break;
+						case TYPE_METHOD: {
+							const MethodTrack *mt = static_cast<const MethodTrack *>(t);
+							_track_get_key_indices_in_range(mt->methods, from_time, length, p_indices);
+							_track_get_key_indices_in_range(mt->methods, to_time, length, p_indices);
+						} break;
+						case TYPE_BEZIER: {
+							const BezierTrack *bz = static_cast<const BezierTrack *>(t);
+							_track_get_key_indices_in_range(bz->values, from_time, length, p_indices);
+							_track_get_key_indices_in_range(bz->values, to_time, length, p_indices);
+						} break;
+						case TYPE_AUDIO: {
+							const AudioTrack *ad = static_cast<const AudioTrack *>(t);
+							_track_get_key_indices_in_range(ad->values, from_time, length, p_indices);
+							_track_get_key_indices_in_range(ad->values, to_time, length, p_indices);
+						} break;
+						case TYPE_ANIMATION: {
+							const AnimationTrack *an = static_cast<const AnimationTrack *>(t);
+							_track_get_key_indices_in_range(an->values, from_time, length, p_indices);
+							_track_get_key_indices_in_range(an->values, to_time, length, p_indices);
+						} break;
+					}
+					return;
+				}
+			}
+		} break;
 	}
 
 	switch (t->type) {
 		case TYPE_TRANSFORM3D: {
 			const TransformTrack *tt = static_cast<const TransformTrack *>(t);
 			_track_get_key_indices_in_range(tt->transforms, from_time, to_time, p_indices);
-
 		} break;
 		case TYPE_VALUE: {
 			const ValueTrack *vt = static_cast<const ValueTrack *>(t);
 			_track_get_key_indices_in_range(vt->values, from_time, to_time, p_indices);
-
 		} break;
 		case TYPE_METHOD: {
 			const MethodTrack *mt = static_cast<const MethodTrack *>(t);
 			_track_get_key_indices_in_range(mt->methods, from_time, to_time, p_indices);
-
 		} break;
 		case TYPE_BEZIER: {
 			const BezierTrack *bz = static_cast<const BezierTrack *>(t);
 			_track_get_key_indices_in_range(bz->values, from_time, to_time, p_indices);
-
 		} break;
 		case TYPE_AUDIO: {
 			const AudioTrack *ad = static_cast<const AudioTrack *>(t);
 			_track_get_key_indices_in_range(ad->values, from_time, to_time, p_indices);
-
 		} break;
 		case TYPE_ANIMATION: {
 			const AnimationTrack *an = static_cast<const AnimationTrack *>(t);
 			_track_get_key_indices_in_range(an->values, from_time, to_time, p_indices);
-
 		} break;
 	}
 }
@@ -2055,7 +2203,7 @@ void Animation::_method_track_get_key_indices_in_range(const MethodTrack *mt, do
 	}
 }
 
-void Animation::method_track_get_key_indices(int p_track, double p_time, double p_delta, List<int> *p_indices) const {
+void Animation::method_track_get_key_indices(int p_track, double p_time, double p_delta, List<int> *p_indices, int p_pingponged) const {
 	ERR_FAIL_INDEX(p_track, tracks.size());
 	Track *t = tracks[p_track];
 	ERR_FAIL_COND(t->type != TYPE_METHOD);
@@ -2069,35 +2217,58 @@ void Animation::method_track_get_key_indices(int p_track, double p_time, double
 		SWAP(from_time, to_time);
 	}
 
-	if (loop) {
-		if (from_time > length || from_time < 0) {
-			from_time = Math::fposmod(from_time, length);
-		}
+	switch (loop_mode) {
+		case LOOP_NONE: {
+			if (from_time < 0) {
+				from_time = 0;
+			}
+			if (from_time > length) {
+				from_time = length;
+			}
 
-		if (to_time > length || to_time < 0) {
-			to_time = Math::fposmod(to_time, length);
-		}
+			if (to_time < 0) {
+				to_time = 0;
+			}
+			if (to_time > length) {
+				to_time = length;
+			}
+		} break;
+		case LOOP_LINEAR: {
+			if (from_time > length || from_time < 0) {
+				from_time = Math::fposmod(from_time, length);
+			}
+			if (to_time > length || to_time < 0) {
+				to_time = Math::fposmod(to_time, length);
+			}
 
-		if (from_time > to_time) {
-			// handle loop by splitting
-			_method_track_get_key_indices_in_range(mt, from_time, length, p_indices);
-			_method_track_get_key_indices_in_range(mt, 0, to_time, p_indices);
-			return;
-		}
-	} else {
-		if (from_time < 0) {
-			from_time = 0;
-		}
-		if (from_time > length) {
-			from_time = length;
-		}
+			if (from_time > to_time) {
+				// handle loop by splitting
+				_method_track_get_key_indices_in_range(mt, from_time, length, p_indices);
+				_method_track_get_key_indices_in_range(mt, 0, to_time, p_indices);
+				return;
+			}
+		} break;
+		case LOOP_PINGPONG: {
+			if (from_time > length || from_time < 0) {
+				from_time = Math::pingpong(from_time, length);
+			}
+			if (to_time > length || to_time < 0) {
+				to_time = Math::pingpong(to_time, length);
+			}
 
-		if (to_time < 0) {
-			to_time = 0;
-		}
-		if (to_time > length) {
-			to_time = length;
-		}
+			if (p_pingponged == -1) {
+				_method_track_get_key_indices_in_range(mt, 0, from_time, p_indices);
+				_method_track_get_key_indices_in_range(mt, 0, to_time, p_indices);
+				return;
+			}
+			if (p_pingponged == 1) {
+				_method_track_get_key_indices_in_range(mt, from_time, length, p_indices);
+				_method_track_get_key_indices_in_range(mt, to_time, length, p_indices);
+				return;
+			}
+		} break;
+		default:
+			break;
 	}
 
 	_method_track_get_key_indices_in_range(mt, from_time, to_time, p_indices);
@@ -2483,13 +2654,13 @@ real_t Animation::get_length() const {
 	return length;
 }
 
-void Animation::set_loop(bool p_enabled) {
-	loop = p_enabled;
+void Animation::set_loop_mode(Animation::LoopMode p_loop_mode) {
+	loop_mode = p_loop_mode;
 	emit_changed();
 }
 
-bool Animation::has_loop() const {
-	return loop;
+Animation::LoopMode Animation::get_loop_mode() const {
+	return loop_mode;
 }
 
 void Animation::track_set_imported(int p_track, bool p_imported) {
@@ -2628,7 +2799,7 @@ void Animation::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("track_set_interpolation_loop_wrap", "track_idx", "interpolation"), &Animation::track_set_interpolation_loop_wrap);
 	ClassDB::bind_method(D_METHOD("track_get_interpolation_loop_wrap", "track_idx"), &Animation::track_get_interpolation_loop_wrap);
 
-	ClassDB::bind_method(D_METHOD("transform_track_interpolate", "track_idx", "time_sec"), &Animation::_transform_track_interpolate);
+	ClassDB::bind_method(D_METHOD("transform_track_interpolate", "track_idx", "time_sec", "is_backward"), &Animation::_transform_track_interpolate, DEFVAL(false));
 	ClassDB::bind_method(D_METHOD("value_track_set_update_mode", "track_idx", "mode"), &Animation::value_track_set_update_mode);
 	ClassDB::bind_method(D_METHOD("value_track_get_update_mode", "track_idx"), &Animation::value_track_get_update_mode);
 
@@ -2666,8 +2837,8 @@ void Animation::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_length", "time_sec"), &Animation::set_length);
 	ClassDB::bind_method(D_METHOD("get_length"), &Animation::get_length);
 
-	ClassDB::bind_method(D_METHOD("set_loop", "enabled"), &Animation::set_loop);
-	ClassDB::bind_method(D_METHOD("has_loop"), &Animation::has_loop);
+	ClassDB::bind_method(D_METHOD("set_loop_mode", "loop_mode"), &Animation::set_loop_mode);
+	ClassDB::bind_method(D_METHOD("get_loop_mode"), &Animation::get_loop_mode);
 
 	ClassDB::bind_method(D_METHOD("set_step", "size_sec"), &Animation::set_step);
 	ClassDB::bind_method(D_METHOD("get_step"), &Animation::get_step);
@@ -2676,7 +2847,7 @@ void Animation::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("copy_track", "track_idx", "to_animation"), &Animation::copy_track);
 
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "length", PROPERTY_HINT_RANGE, "0.001,99999,0.001"), "set_length", "get_length");
-	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "loop"), "set_loop", "has_loop");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "loop_mode"), "set_loop_mode", "get_loop_mode");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "step", PROPERTY_HINT_RANGE, "0,4096,0.001"), "set_step", "get_step");
 
 	ADD_SIGNAL(MethodInfo("tracks_changed"));
@@ -2696,6 +2867,10 @@ void Animation::_bind_methods() {
 	BIND_ENUM_CONSTANT(UPDATE_DISCRETE);
 	BIND_ENUM_CONSTANT(UPDATE_TRIGGER);
 	BIND_ENUM_CONSTANT(UPDATE_CAPTURE);
+
+	BIND_ENUM_CONSTANT(LOOP_NONE);
+	BIND_ENUM_CONSTANT(LOOP_LINEAR);
+	BIND_ENUM_CONSTANT(LOOP_PINGPONG);
 }
 
 void Animation::clear() {
@@ -2703,7 +2878,7 @@ void Animation::clear() {
 		memdelete(tracks[i]);
 	}
 	tracks.clear();
-	loop = false;
+	loop_mode = LOOP_NONE;
 	length = 1;
 	emit_changed();
 	emit_signal(SceneStringNames::get_singleton()->tracks_changed);
diff --git a/scene/resources/animation.h b/scene/resources/animation.h
index 9a410bd566..032b1a9277 100644
--- a/scene/resources/animation.h
+++ b/scene/resources/animation.h
@@ -60,7 +60,12 @@ public:
 		UPDATE_DISCRETE,
 		UPDATE_TRIGGER,
 		UPDATE_CAPTURE,
+	};
 
+	enum LoopMode {
+		LOOP_NONE,
+		LOOP_LINEAR,
+		LOOP_PINGPONG,
 	};
 
 private:
@@ -184,7 +189,8 @@ private:
 	int _insert(double p_time, T &p_keys, const V &p_value);
 
 	template <class K>
-	inline int _find(const Vector<K> &p_keys, double p_time) const;
+
+	inline int _find(const Vector<K> &p_keys, double p_time, bool p_backward = false) const;
 
 	_FORCE_INLINE_ Animation::TransformKey _interpolate(const Animation::TransformKey &p_a, const Animation::TransformKey &p_b, real_t p_c) const;
 
@@ -200,7 +206,7 @@ private:
 	_FORCE_INLINE_ real_t _cubic_interpolate(const real_t &p_pre_a, const real_t &p_a, const real_t &p_b, const real_t &p_post_b, real_t p_c) const;
 
 	template <class T>
-	_FORCE_INLINE_ T _interpolate(const Vector<TKey<T>> &p_keys, double p_time, InterpolationType p_interp, bool p_loop_wrap, bool *p_ok) const;
+	_FORCE_INLINE_ T _interpolate(const Vector<TKey<T>> &p_keys, double p_time, InterpolationType p_interp, bool p_loop_wrap, bool *p_ok, bool p_backward = false) const;
 
 	template <class T>
 	_FORCE_INLINE_ void _track_get_key_indices_in_range(const Vector<T> &p_array, double from_time, double to_time, List<int> *p_indices) const;
@@ -210,15 +216,16 @@ private:
 
 	double length = 1.0;
 	real_t step = 0.1;
-	bool loop = false;
+	LoopMode loop_mode = LOOP_NONE;
+	int pingponged = 0;
 
 	// bind helpers
 private:
-	Array _transform_track_interpolate(int p_track, double p_time) const {
+	Array _transform_track_interpolate(int p_track, double p_time, bool p_backward = false) const {
 		Vector3 loc;
 		Quaternion rot;
 		Vector3 scale;
-		transform_track_interpolate(p_track, p_time, &loc, &rot, &scale);
+		transform_track_interpolate(p_track, p_time, &loc, &rot, &scale, p_backward);
 		Array ret;
 		ret.push_back(loc);
 		ret.push_back(rot);
@@ -324,26 +331,26 @@ public:
 	void track_set_interpolation_loop_wrap(int p_track, bool p_enable);
 	bool track_get_interpolation_loop_wrap(int p_track) const;
 
-	Error transform_track_interpolate(int p_track, double p_time, Vector3 *r_loc, Quaternion *r_rot, Vector3 *r_scale) const;
+	Error transform_track_interpolate(int p_track, double p_time, Vector3 *r_loc, Quaternion *r_rot, Vector3 *r_scale, bool p_backward = false) const;
 
 	Variant value_track_interpolate(int p_track, double p_time) const;
-	void value_track_get_key_indices(int p_track, double p_time, double p_delta, List<int> *p_indices) const;
+	void value_track_get_key_indices(int p_track, double p_time, double p_delta, List<int> *p_indices, int p_pingponged = 0) const;
 	void value_track_set_update_mode(int p_track, UpdateMode p_mode);
 	UpdateMode value_track_get_update_mode(int p_track) const;
 
-	void method_track_get_key_indices(int p_track, double p_time, double p_delta, List<int> *p_indices) const;
+	void method_track_get_key_indices(int p_track, double p_time, double p_delta, List<int> *p_indices, int p_pingponged = 0) const;
 	Vector<Variant> method_track_get_params(int p_track, int p_key_idx) const;
 	StringName method_track_get_name(int p_track, int p_key_idx) const;
 
 	void copy_track(int p_track, Ref<Animation> p_to_animation);
 
-	void track_get_key_indices_in_range(int p_track, double p_time, double p_delta, List<int> *p_indices) const;
+	void track_get_key_indices_in_range(int p_track, double p_time, double p_delta, List<int> *p_indices, int p_pingponged = 0) const;
 
 	void set_length(real_t p_length);
 	real_t get_length() const;
 
-	void set_loop(bool p_enabled);
-	bool has_loop() const;
+	void set_loop_mode(LoopMode p_loop_mode);
+	LoopMode get_loop_mode() const;
 
 	void set_step(real_t p_step);
 	real_t get_step() const;
@@ -359,5 +366,6 @@ public:
 VARIANT_ENUM_CAST(Animation::TrackType);
 VARIANT_ENUM_CAST(Animation::InterpolationType);
 VARIANT_ENUM_CAST(Animation::UpdateMode);
+VARIANT_ENUM_CAST(Animation::LoopMode);
 
 #endif
diff --git a/scene/resources/audio_stream_sample.cpp b/scene/resources/audio_stream_sample.cpp
index d018103e64..c8a10e1c2a 100644
--- a/scene/resources/audio_stream_sample.cpp
+++ b/scene/resources/audio_stream_sample.cpp
@@ -299,7 +299,7 @@ int AudioStreamPlaybackSample::mix(AudioFrame *p_buffer, float p_rate_scale, int
 
 			if (loop_format != AudioStreamSample::LOOP_DISABLED && offset < loop_begin_fp) {
 				/* loopstart reached */
-				if (loop_format == AudioStreamSample::LOOP_PING_PONG) {
+				if (loop_format == AudioStreamSample::LOOP_PINGPONG) {
 					/* bounce ping pong */
 					offset = loop_begin_fp + (loop_begin_fp - offset);
 					increment = -increment;
@@ -320,7 +320,7 @@ int AudioStreamPlaybackSample::mix(AudioFrame *p_buffer, float p_rate_scale, int
 			if (loop_format != AudioStreamSample::LOOP_DISABLED && offset >= loop_end_fp) {
 				/* loopend reached */
 
-				if (loop_format == AudioStreamSample::LOOP_PING_PONG) {
+				if (loop_format == AudioStreamSample::LOOP_PINGPONG) {
 					/* bounce ping pong */
 					offset = loop_end_fp - (offset - loop_end_fp);
 					increment = -increment;
@@ -650,7 +650,7 @@ void AudioStreamSample::_bind_methods() {
 
 	BIND_ENUM_CONSTANT(LOOP_DISABLED);
 	BIND_ENUM_CONSTANT(LOOP_FORWARD);
-	BIND_ENUM_CONSTANT(LOOP_PING_PONG);
+	BIND_ENUM_CONSTANT(LOOP_PINGPONG);
 	BIND_ENUM_CONSTANT(LOOP_BACKWARD);
 }
 
diff --git a/scene/resources/audio_stream_sample.h b/scene/resources/audio_stream_sample.h
index 24198e3c98..0eb34be9bf 100644
--- a/scene/resources/audio_stream_sample.h
+++ b/scene/resources/audio_stream_sample.h
@@ -92,7 +92,7 @@ public:
 	enum LoopMode {
 		LOOP_DISABLED,
 		LOOP_FORWARD,
-		LOOP_PING_PONG,
+		LOOP_PINGPONG,
 		LOOP_BACKWARD
 	};