Address feedback

src/Cameras/Inputs/babylon.freeCameraMouseInput.ts

@@ -74,14 +74,11 @@ module BABYLON {
                         }
 
                         var offsetX = evt.clientX - this.previousPosition.x;
-                        var offsetY = evt.clientY - this.previousPosition.y;
-
-                        if (this.camera.getScene().useRightHandedSystem === (this.camera.parent && this.camera.parent._getWorldMatrixDeterminant() >= 0)) {
-                            this.camera.cameraRotation.y -= offsetX / this.angularSensibility;
-                        } else {
-                            this.camera.cameraRotation.y += offsetX / this.angularSensibility;
-                        }
+                        if (this.camera.getScene().useRightHandedSystem) offsetX *= -1;
+                        if (this.camera.parent && this.camera.parent._getWorldMatrixDeterminant() < 0) offsetX *= -1;
+                        this.camera.cameraRotation.y += offsetX / this.angularSensibility;
 
+                        var offsetY = evt.clientY - this.previousPosition.y;
                         this.camera.cameraRotation.x += offsetY / this.angularSensibility;
 
                         this.previousPosition = {
@@ -106,14 +103,11 @@ module BABYLON {
                 }
 
                 var offsetX = evt.movementX || evt.mozMovementX || evt.webkitMovementX || evt.msMovementX || 0;
-                var offsetY = evt.movementY || evt.mozMovementY || evt.webkitMovementY || evt.msMovementY || 0;
-
-                if (this.camera.getScene().useRightHandedSystem === (this.camera.parent && this.camera.parent._getWorldMatrixDeterminant() >= 0)) {
-                    this.camera.cameraRotation.y -= offsetX / this.angularSensibility;
-                } else {
-                    this.camera.cameraRotation.y += offsetX / this.angularSensibility;
-                }
+                if (this.camera.getScene().useRightHandedSystem) offsetX *= -1;
+                if (this.camera.parent && this.camera.parent._getWorldMatrixDeterminant() < 0) offsetX *= -1;
+                this.camera.cameraRotation.y += offsetX / this.angularSensibility;
 
+                var offsetY = evt.movementY || evt.mozMovementY || evt.webkitMovementY || evt.msMovementY || 0;
                 this.camera.cameraRotation.x += offsetY / this.angularSensibility;
 
                 this.previousPosition = null;

src/Cameras/babylon.arcRotateCamera.ts

@@ -484,12 +484,11 @@
             this.inputs.checkInputs();
             // Inertia
             if (this.inertialAlphaOffset !== 0 || this.inertialBetaOffset !== 0 || this.inertialRadiusOffset !== 0) {
-
-                if (this.getScene().useRightHandedSystem === (this.parent && this.parent._getWorldMatrixDeterminant() >= 0)) {
-                    this.alpha -= this.beta <= 0 ? -this.inertialAlphaOffset : this.inertialAlphaOffset;
-                } else {
-                    this.alpha += this.beta <= 0 ? -this.inertialAlphaOffset : this.inertialAlphaOffset;
-                }
+                let inertialAlphaOffset = this.inertialAlphaOffset;
+                if (this.beta <= 0) inertialAlphaOffset *= -1;
+                if (this.getScene().useRightHandedSystem) inertialAlphaOffset *= -1;
+                if (this.parent && this.parent._getWorldMatrixDeterminant() < 0) inertialAlphaOffset *= -1;
+                this.alpha += inertialAlphaOffset;
 
                 this.beta += this.inertialBetaOffset;
 

src/Cameras/babylon.camera.ts

@@ -160,7 +160,7 @@
         private _computedViewMatrix = Matrix.Identity();
         public _projectionMatrix = new Matrix();
         private _doNotComputeProjectionMatrix = false;
-        private _worldMatrix: Matrix;
+        private _worldMatrix = Matrix.Identity();
         public _postProcesses = new Array<Nullable<PostProcess>>();
         private _transformMatrix = Matrix.Zero();
 
@@ -435,13 +435,12 @@
         }
 
         public getWorldMatrix(): Matrix {
-            if (!this._worldMatrix) {
-                this._worldMatrix = Matrix.Identity();
+            if (this._isSynchronizedViewMatrix()) {
+                return this._worldMatrix;
             }
 
-            var viewMatrix = this.getViewMatrix();
-
-            viewMatrix.invertToRef(this._worldMatrix);
+            // Getting the the view matrix will also compute the world matrix.
+            this.getViewMatrix();
 
             return this._worldMatrix;
         }
@@ -468,6 +467,8 @@
 
             this.onViewMatrixChangedObservable.notifyObservers(this);
 
+            this._computedViewMatrix.invertToRef(this._worldMatrix);
+
             return this._computedViewMatrix;
         }