Merge pull request #69199 from TokageItLab/fix-and-refactor-root-motion

Fix broken root motion scale & Refactor API & Add sample codes in documentation

3 files changed, 30 insertions, 16 deletions

diff --git a/scene/animation/animation_tree.cpp b/scene/animation/animation_tree.cpp
index 8729ab156b..9382456f24 100644
--- a/scene/animation/animation_tree.cpp
+++ b/scene/animation/animation_tree.cpp
@@ -883,7 +883,9 @@ void AnimationTree::_process_graph(double p_delta) {
 	_update_properties(); //if properties need updating, update them
 
 	//check all tracks, see if they need modification
-	root_motion_transform = Transform3D();
+	root_motion_position = Vector3(0, 0, 0);
+	root_motion_rotation = Quaternion(0, 0, 0, 1);
+	root_motion_scale = Vector3(0, 0, 0);
 
 	if (!root.is_valid()) {
 		ERR_PRINT("AnimationTree: root AnimationNode is not set, disabling playback.");
@@ -982,7 +984,7 @@ void AnimationTree::_process_graph(double p_delta) {
 					if (track->root_motion) {
 						t->loc = Vector3(0, 0, 0);
 						t->rot = Quaternion(0, 0, 0, 1);
-						t->scale = Vector3(0, 0, 0);
+						t->scale = Vector3(1, 1, 1);
 					} else {
 						t->loc = t->init_loc;
 						t->rot = t->init_rot;
@@ -1627,11 +1629,9 @@ void AnimationTree::_process_graph(double p_delta) {
 					TrackCacheTransform *t = static_cast<TrackCacheTransform *>(track);
 
 					if (t->root_motion) {
-						Transform3D xform;
-						xform.origin = t->loc;
-						xform.basis.set_quaternion_scale(t->rot, Vector3(1, 1, 1) + t->scale);
-
-						root_motion_transform = xform;
+						root_motion_position = root_motion_rotation.xform_inv(t->loc);
+						root_motion_rotation = t->rot;
+						root_motion_scale = t->scale - Vector3(1, 1, 1);
 
 					} else if (t->skeleton && t->bone_idx >= 0) {
 						if (t->loc_used) {
@@ -1844,8 +1844,16 @@ NodePath AnimationTree::get_root_motion_track() const {
 	return root_motion_track;
 }
 
-Transform3D AnimationTree::get_root_motion_transform() const {
-	return root_motion_transform;
+Vector3 AnimationTree::get_root_motion_position() const {
+	return root_motion_position;
+}
+
+Quaternion AnimationTree::get_root_motion_rotation() const {
+	return root_motion_rotation;
+}
+
+Vector3 AnimationTree::get_root_motion_scale() const {
+	return root_motion_scale;
 }
 
 void AnimationTree::_tree_changed() {
@@ -2003,7 +2011,9 @@ void AnimationTree::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_root_motion_track", "path"), &AnimationTree::set_root_motion_track);
 	ClassDB::bind_method(D_METHOD("get_root_motion_track"), &AnimationTree::get_root_motion_track);
 
-	ClassDB::bind_method(D_METHOD("get_root_motion_transform"), &AnimationTree::get_root_motion_transform);
+	ClassDB::bind_method(D_METHOD("get_root_motion_position"), &AnimationTree::get_root_motion_position);
+	ClassDB::bind_method(D_METHOD("get_root_motion_rotation"), &AnimationTree::get_root_motion_rotation);
+	ClassDB::bind_method(D_METHOD("get_root_motion_scale"), &AnimationTree::get_root_motion_scale);
 
 	ClassDB::bind_method(D_METHOD("_update_properties"), &AnimationTree::_update_properties);
 
diff --git a/scene/animation/animation_tree.h b/scene/animation/animation_tree.h
index 84d0a8190a..2dbac34666 100644
--- a/scene/animation/animation_tree.h
+++ b/scene/animation/animation_tree.h
@@ -294,7 +294,9 @@ private:
 	bool started = true;
 
 	NodePath root_motion_track;
-	Transform3D root_motion_transform;
+	Vector3 root_motion_position = Vector3(0, 0, 0);
+	Quaternion root_motion_rotation = Quaternion(0, 0, 0, 1);
+	Vector3 root_motion_scale = Vector3(0, 0, 0);
 
 	friend class AnimationNode;
 	bool properties_dirty = true;
@@ -350,7 +352,9 @@ public:
 	void set_root_motion_track(const NodePath &p_track);
 	NodePath get_root_motion_track() const;
 
-	Transform3D get_root_motion_transform() const;
+	Vector3 get_root_motion_position() const;
+	Quaternion get_root_motion_rotation() const;
+	Vector3 get_root_motion_scale() const;
 
 	real_t get_connection_activity(const StringName &p_path, int p_connection) const;
 	void advance(double p_time);
diff --git a/scene/animation/root_motion_view.cpp b/scene/animation/root_motion_view.cpp
index 47f08219a9..a6ccb4a576 100644
--- a/scene/animation/root_motion_view.cpp
+++ b/scene/animation/root_motion_view.cpp
@@ -103,7 +103,8 @@ void RootMotionView::_notification(int p_what) {
 						set_physics_process_internal(false);
 					}
 
-					transform = tree->get_root_motion_transform();
+					transform.origin = tree->get_root_motion_position();
+					transform.basis = tree->get_root_motion_rotation(); // Scale is meaningless.
 				}
 			}
 
@@ -113,9 +114,8 @@ void RootMotionView::_notification(int p_what) {
 
 			first = false;
 
-			transform.orthonormalize(); //don't want scale, too imprecise
-
-			accumulated = accumulated * transform;
+			accumulated.origin += transform.origin;
+			accumulated.basis *= transform.basis;
 			accumulated.origin.x = Math::fposmod(accumulated.origin.x, cell_size);
 			if (zero_y) {
 				accumulated.origin.y = 0;