WIP: RH camera fixes

Author: bghgary

packages/dev/core/src/Cameras/targetCamera.ts

@@ -12,6 +12,10 @@ Node.AddNodeConstructor("TargetCamera", (name, scene) => {
     return () => new TargetCamera(name, Vector3.Zero(), scene);
 });
 
+// Temporary cache variables to avoid allocations.
+const TmpMatrix = Matrix.Zero();
+const TmpQuaternion = Quaternion.Identity();
+
 /**
  * A target camera takes a mesh or position as a target and continues to look at it while it moves.
  * This is the base of the follow, arc rotate cameras and Free camera
@@ -36,7 +40,6 @@ export class TargetCamera extends Camera {
      */
     @serialize()
     public updateUpVectorFromRotation = false;
-    private _tmpQuaternion = new Quaternion();
 
     /**
      * Define the current rotation of the camera
@@ -79,35 +82,27 @@ export class TargetCamera extends Camera {
     @serializeAsMeshReference("lockedTargetId")
     public lockedTarget: any = null;
 
-    /** @internal */
-    public _currentTarget = Vector3.Zero();
-    /** @internal */
-    public _initialFocalDistance = 1;
-    /** @internal */
-    public _viewMatrix = Matrix.Zero();
-    /** @internal */
-    public _camMatrix = Matrix.Zero();
-    /** @internal */
-    public _cameraTransformMatrix = Matrix.Zero();
-    /** @internal */
-    public _cameraRotationMatrix = Matrix.Zero();
+    protected readonly _currentTarget = Vector3.Zero();
+    protected _initialFocalDistance = 1;
+    protected readonly _viewMatrix = Matrix.Zero();
 
     /** @internal */
-    public _referencePoint = new Vector3(0, 0, 1);
+    public readonly _cameraTransformMatrix = Matrix.Zero();
     /** @internal */
-    public _transformedReferencePoint = Vector3.Zero();
+    public readonly _cameraRotationMatrix = Matrix.Zero();
+
+    protected readonly _referencePoint: Vector3;
+    protected readonly _transformedReferencePoint = Vector3.Zero();
 
-    protected _deferredPositionUpdate = new Vector3();
-    protected _deferredRotationQuaternionUpdate = new Quaternion();
-    protected _deferredRotationUpdate = new Vector3();
+    protected readonly _deferredPositionUpdate = new Vector3();
+    protected readonly _deferredRotationQuaternionUpdate = new Quaternion();
+    protected readonly _deferredRotationUpdate = new Vector3();
     protected _deferredUpdated = false;
     protected _deferOnly: boolean = false;
 
     /** @internal */
     public _reset: () => void;
 
-    private _defaultUp = Vector3.Up();
-
     /**
      * Instantiates a target camera that takes a mesh or position as a target and continues to look at it while it moves.
      * This is the base of the follow, arc rotate cameras and Free camera
@@ -119,6 +114,8 @@ export class TargetCamera extends Camera {
      */
     constructor(name: string, position: Vector3, scene?: Scene, setActiveOnSceneIfNoneActive = true) {
         super(name, position, scene, setActiveOnSceneIfNoneActive);
+
+        this._referencePoint = Vector3.Forward(this.getScene().useRightHandedSystem);
     }
 
     /**
@@ -255,6 +252,7 @@ export class TargetCamera extends Camera {
      * @param target Defines the new target as a Vector
      */
     public setTarget(target: Vector3): void {
+        // REVIEW: why is this here?
         this.upVector.normalize();
 
         this._initialFocalDistance = target.subtract(this.position).length();
@@ -263,38 +261,19 @@ export class TargetCamera extends Camera {
             this.position.z += Epsilon;
         }
 
-        this._referencePoint.normalize().scaleInPlace(this._initialFocalDistance);
-
-        Matrix.LookAtLHToRef(this.position, target, this._defaultUp, this._camMatrix);
-        this._camMatrix.invert();
+        this._referencePoint.scaleInPlace(this._initialFocalDistance);
 
-        this.rotation.x = Math.atan(this._camMatrix.m[6] / this._camMatrix.m[10]);
-
-        const vDir = target.subtract(this.position);
-
-        if (vDir.x >= 0.0) {
-            this.rotation.y = -Math.atan(vDir.z / vDir.x) + Math.PI / 2.0;
+        if (this.getScene().useRightHandedSystem) {
+            Matrix.LookAtRHToRef(this.position, target, Vector3.UpReadOnly, TmpMatrix);
         } else {
-            this.rotation.y = -Math.atan(vDir.z / vDir.x) - Math.PI / 2.0;
+            Matrix.LookAtLHToRef(this.position, target, Vector3.UpReadOnly, TmpMatrix);
         }
+        TmpMatrix.invert();
 
-        this.rotation.z = 0;
+        const rotationQuaternion = this.rotationQuaternion || TmpQuaternion;
+        Quaternion.FromRotationMatrixToRef(TmpMatrix, rotationQuaternion);
 
-        if (isNaN(this.rotation.x)) {
-            this.rotation.x = 0;
-        }
-
-        if (isNaN(this.rotation.y)) {
-            this.rotation.y = 0;
-        }
-
-        if (isNaN(this.rotation.z)) {
-            this.rotation.z = 0;
-        }
-
-        if (this.rotationQuaternion) {
-            Quaternion.RotationYawPitchRollToRef(this.rotation.y, this.rotation.x, this.rotation.z, this.rotationQuaternion);
-        }
+        rotationQuaternion.toEulerAnglesToRef(this.rotation);
     }
 
     /**
@@ -450,7 +429,7 @@ export class TargetCamera extends Camera {
      * @returns the current camera
      */
     private _rotateUpVectorWithCameraRotationMatrix(): TargetCamera {
-        Vector3.TransformNormalToRef(this._defaultUp, this._cameraRotationMatrix, this.upVector);
+        Vector3.TransformNormalToRef(Vector3.UpReadOnly, this._cameraRotationMatrix, this.upVector);
         return this;
     }
 
@@ -482,8 +461,8 @@ export class TargetCamera extends Camera {
             if (this.rotationQuaternion) {
                 Axis.Y.rotateByQuaternionToRef(this.rotationQuaternion, this.upVector);
             } else {
-                Quaternion.FromEulerVectorToRef(this.rotation, this._tmpQuaternion);
-                Axis.Y.rotateByQuaternionToRef(this._tmpQuaternion, this.upVector);
+                Quaternion.FromEulerVectorToRef(this.rotation, TmpQuaternion);
+                Axis.Y.rotateByQuaternionToRef(TmpQuaternion, this.upVector);
             }
         }
         this._computeViewMatrix(this.position, this._currentTarget, this.upVector);

packages/dev/loaders/src/glTF/2.0/glTFLoader.ts

@@ -1569,8 +1569,8 @@ export class GLTFLoader implements IGLTFLoader {
         this._babylonScene._blockEntityCollection = false;
         camera._babylonCamera = babylonCamera;
 
-        // Rotation by 180 as glTF has a different convention than Babylon.
-        babylonCamera.rotation.set(0, Math.PI, 0);
+        // glTF cameras look towards the local -Z axis.
+        babylonCamera.setTarget(new Vector3(0, 0, -1));
 
         switch (camera.type) {
             case CameraType.PERSPECTIVE: {