From b766ac48d5a4d3da194bc2838465538d3c4952e4 Mon Sep 17 00:00:00 2001
From: Popov72 <github@evpopov.com>
Date: Sat, 28 Feb 2026 15:24:47 +0100
Subject: [PATCH 1/2] Fix regression

---
 .../dev/core/src/Animations/animatorAvatar.ts | 29 ++++++++++---------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/packages/dev/core/src/Animations/animatorAvatar.ts b/packages/dev/core/src/Animations/animatorAvatar.ts
index 3b20221f2ca..367adee2863 100644
--- a/packages/dev/core/src/Animations/animatorAvatar.ts
+++ b/packages/dev/core/src/Animations/animatorAvatar.ts
@@ -89,7 +89,7 @@ export interface IRetargetOptions {
     mapNodeNames?: Map<string, string>;
 }
 
-type TransformNodeNameToNode = Map<string, { node: TransformNode; initialTransformations: { position: Vector3; scaling: Vector3; quaternion: Quaternion } }>;
+type TransformNodeNameToNode = Map<string, { node: TransformNode; initialTransformations: { position: Vector3; scaling: Vector3; quaternion: Quaternion; rotation: Vector3 } }>;
 
 /**
  * Represents an animator avatar that manages meshes, skeletons and morph target managers for a hierarchical transform node and mesh structure.
@@ -158,14 +158,11 @@ export class AnimatorAvatar {
             this._collectMesh(rootNode);
         }
 
-        rootNode
-            .getChildMeshes(false, (node) => {
-                const mesh = node as AbstractMesh;
-                return mesh.getTotalVertices() > 0;
-            })
-            .forEach((mesh) => {
+        rootNode.getChildMeshes(false).forEach((mesh) => {
+            if (mesh.getTotalVertices() > 0) {
                 this._collectMesh(mesh);
-            });
+            }
+        });
 
         this._computeBoneWorldMatrices();
     }
@@ -282,6 +279,7 @@ export class AnimatorAvatar {
                         position: tn.position.clone(),
                         scaling: tn.scaling.clone(),
                         quaternion: tn.rotationQuaternion.clone(),
+                        rotation: tn.rotation.clone(),
                     },
                 });
             }
@@ -339,9 +337,9 @@ export class AnimatorAvatar {
                             Logger.Warn(
                                 `RetargetAnimationGroup - Avatar '${this.name}', AnimationGroup '${animationGroup.name}': "${sourceTransformNodeName}" bone not found in any skeleton of avatar: animation removed.`
                             );
-                            animationGroup.targetedAnimations.splice(i, 1);
-                            i--;
                         }
+                        animationGroup.targetedAnimations.splice(i, 1);
+                        i--;
                         break;
                     }
 
@@ -465,6 +463,7 @@ export class AnimatorAvatar {
 
     private _computeBoneWorldMatrices() {
         this.skeletons.forEach((skeleton) => {
+            skeleton.returnToRest();
             skeleton.prepare(true);
 
             skeleton.bones.forEach((bone) => {
@@ -842,9 +841,13 @@ export class AnimatorAvatar {
 
         sourceTransformNodeNameToNode.forEach((data) => {
             const { node, initialTransformations } = data;
-            node.position = initialTransformations.position;
-            node.scaling = initialTransformations.scaling;
-            node.rotationQuaternion = initialTransformations.quaternion;
+            node.position.copyFrom(initialTransformations.position);
+            node.scaling.copyFrom(initialTransformations.scaling);
+            if (node.rotationQuaternion) {
+                node.rotationQuaternion.copyFrom(initialTransformations.quaternion);
+            } else {
+                node.rotation.copyFrom(initialTransformations.rotation);
+            }
             node.computeWorldMatrix(true);
         });
     }

From 78fb168ccf7e7bf52804ef192303d80732b05c2b Mon Sep 17 00:00:00 2001
From: Popov72 <github@evpopov.com>
Date: Sat, 28 Feb 2026 15:47:34 +0100
Subject: [PATCH 2/2] Fix quaternion usage

---
 .../dev/core/src/Animations/animatorAvatar.ts | 20 +++++++++----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/packages/dev/core/src/Animations/animatorAvatar.ts b/packages/dev/core/src/Animations/animatorAvatar.ts
index 367adee2863..e8f7b851c6b 100644
--- a/packages/dev/core/src/Animations/animatorAvatar.ts
+++ b/packages/dev/core/src/Animations/animatorAvatar.ts
@@ -89,7 +89,7 @@ export interface IRetargetOptions {
     mapNodeNames?: Map<string, string>;
 }
 
-type TransformNodeNameToNode = Map<string, { node: TransformNode; initialTransformations: { position: Vector3; scaling: Vector3; quaternion: Quaternion; rotation: Vector3 } }>;
+type TransformNodeNameToNode = Map<string, { node: TransformNode; initialTransformations: { position: Vector3; scaling: Vector3; quaternion?: Quaternion; rotation: Vector3 } }>;
 
 /**
  * Represents an animator avatar that manages meshes, skeletons and morph target managers for a hierarchical transform node and mesh structure.
@@ -163,8 +163,6 @@ export class AnimatorAvatar {
                 this._collectMesh(mesh);
             }
         });
-
-        this._computeBoneWorldMatrices();
     }
 
     private _collectMesh(mesh: AbstractMesh) {
@@ -268,20 +266,20 @@ export class AnimatorAvatar {
 
                 lstSourceTransformNodes.add(tn);
 
-                if (!tn.rotationQuaternion) {
-                    tn.rotationQuaternion = Quaternion.FromEulerAngles(tn.rotation.x, tn.rotation.y, tn.rotation.z);
-                    tn.rotation.setAll(0);
-                }
-
                 sourceTransformNodeNameToNode.set(mapNodeNames.get(tn.name) ?? tn.name, {
                     node: tn,
                     initialTransformations: {
                         position: tn.position.clone(),
                         scaling: tn.scaling.clone(),
-                        quaternion: tn.rotationQuaternion.clone(),
+                        quaternion: tn.rotationQuaternion?.clone(),
                         rotation: tn.rotation.clone(),
                     },
                 });
+
+                if (!tn.rotationQuaternion) {
+                    tn.rotationQuaternion = Quaternion.FromEulerAngles(tn.rotation.x, tn.rotation.y, tn.rotation.z);
+                    tn.rotation.setAll(0);
+                }
             }
         }
 
@@ -843,8 +841,8 @@ export class AnimatorAvatar {
             const { node, initialTransformations } = data;
             node.position.copyFrom(initialTransformations.position);
             node.scaling.copyFrom(initialTransformations.scaling);
-            if (node.rotationQuaternion) {
-                node.rotationQuaternion.copyFrom(initialTransformations.quaternion);
+            if (initialTransformations.quaternion) {
+                node.rotationQuaternion!.copyFrom(initialTransformations.quaternion);
             } else {
                 node.rotation.copyFrom(initialTransformations.rotation);
             }