Small fix VRHelper

dist/preview release/babylon.max.js

@@ -68653,7 +68653,7 @@ var BABYLON;
             // Are we presenting in the fullscreen fallback?
             this._fullscreenVRpresenting = false;
             this._scene = scene;
-            if (!this._scene.activeCamera) {
+            if (!this._scene.activeCamera || isNaN(this._scene.activeCamera.position.x)) {
                 this._deviceOrientationCamera = new BABYLON.DeviceOrientationCamera("deviceOrientationVRHelper", new BABYLON.Vector3(0, 2, 0), scene);
             }
             else {

dist/preview release/customConfigurations/minimalGLTFViewer/babylon.max.js

@@ -68653,7 +68653,7 @@ var BABYLON;
             // Are we presenting in the fullscreen fallback?
             this._fullscreenVRpresenting = false;
             this._scene = scene;
-            if (!this._scene.activeCamera) {
+            if (!this._scene.activeCamera || isNaN(this._scene.activeCamera.position.x)) {
                 this._deviceOrientationCamera = new BABYLON.DeviceOrientationCamera("deviceOrientationVRHelper", new BABYLON.Vector3(0, 2, 0), scene);
             }
             else {

src/Cameras/VR/babylon.vrExperienceHelper.ts

@@ -34,7 +34,7 @@ module BABYLON {
         constructor(scene: Scene, public webVROptions: WebVROptions = {}) {
             this._scene = scene;
 
-            if (!this._scene.activeCamera) {
+            if (!this._scene.activeCamera || isNaN(this._scene.activeCamera.position.x)) {
                 this._deviceOrientationCamera = new BABYLON.DeviceOrientationCamera("deviceOrientationVRHelper", new BABYLON.Vector3(0, 2, 0), scene);
             }
             else {