add new parameter to createDefaultSkybox to avoid setting the scene.env texture

dist/preview release/what's new.md

@@ -14,7 +14,7 @@
 - Added [GlowLayer](https://doc.babylonjs.com/how_to/glow_layer) to easily support glow from emissive materials. Demo [here](http://www.babylonjs.com/demos/GlowLayer/) ([sebavan](https://github.com/sebavan))
 - New [AssetContainer](http://doc.babylonjs.com/how_to/how_to_use_assetcontainer) class and loading methods ([trevordev](https://github.com/trevordev))
 - Added [depth of field](https://www.babylonjs-playground.com/frame.html#8F5HYV#9), [MSAA, sharpening, chromatic aberration and grain effect](https://www.babylonjs-playground.com/#Y3C0HQ#146) to the default pipeline ([trevordev](https://github.com/trevordev))
-- Added support for [animation weights](http://doc.babylonjs.com/babylon101/animations#animation-weights). Demo [here](https://www.babylonjs-playground.com/#IQN716#9) ([deltakosh](https://github.com/deltakosh))
+- Added support for [animation weights](http://doc.babylonjs.com/babylon101/animations#animation-weights). Demo [here](https://www.babylonjs-playground.com/#LL5BIQ) ([deltakosh](https://github.com/deltakosh))
 - Added [sub emitters for particle system](http://doc.babylonjs.com/babylon101/particles#sub-emitters) which will spawn new particle systems when particles dies. Demo [here](https://www.babylonjs-playground.com/frame.html#9NHBCC#1) ([IbraheemOsama](https://github.com/IbraheemOsama))
 - New [Babylon.js](http://doc.babylonjs.com/resources/maya) and [glTF](http://doc.babylonjs.com/resources/maya_to_gltf) exporter for Autodesk Maya ([Noalak](https://github.com/Noalak))
 - New glTF [serializer](https://github.com/BabylonJS/Babylon.js/tree/master/serializers/src/glTF/2.0). You can now export glTF or glb files directly from a Babylon scene ([kcoley](https://github.com/kcoley))

src/babylon.scene.ts

@@ -5885,24 +5885,28 @@
          * @param pbr defines if PBRMaterial must be used instead of StandardMaterial
          * @param scale defines the overall scale of the skybox
          * @param blur defines if blurring must be applied to the environment texture (works only with pbr === true)
+         * @param setGlobalEnvTexture defines a boolean indicating that scene.environmentTexture must match the current skybox texture (true by default)
          * @returns a new mesh holding the sky box
          */
-        public createDefaultSkybox(environmentTexture?: BaseTexture, pbr = false, scale = 1000, blur = 0): Nullable<Mesh> {
-            if (environmentTexture) {
-                this.environmentTexture = environmentTexture;
-            }
+        public createDefaultSkybox(environmentTexture?: BaseTexture, pbr = false, scale = 1000, blur = 0, setGlobalEnvTexture = true): Nullable<Mesh> {
 
-            if (!this.environmentTexture) {
+            if (!environmentTexture) {
                 Tools.Warn("Can not create default skybox without environment texture.");
                 return null;
             }
 
+            if (setGlobalEnvTexture) {
+                if (environmentTexture) {
+                    this.environmentTexture = environmentTexture;
+                }
+            }
+
             // Skybox
             var hdrSkybox = Mesh.CreateBox("hdrSkyBox", scale, this);
             if (pbr) {
                 let hdrSkyboxMaterial = new PBRMaterial("skyBox", this);
                 hdrSkyboxMaterial.backFaceCulling = false;
-                hdrSkyboxMaterial.reflectionTexture = this.environmentTexture.clone();
+                hdrSkyboxMaterial.reflectionTexture = environmentTexture.clone();
                 if (hdrSkyboxMaterial.reflectionTexture) {
                     hdrSkyboxMaterial.reflectionTexture.coordinatesMode = Texture.SKYBOX_MODE;
                 }
@@ -5915,7 +5919,7 @@
             else {
                 let skyboxMaterial = new StandardMaterial("skyBox", this);
                 skyboxMaterial.backFaceCulling = false;
-                skyboxMaterial.reflectionTexture = this.environmentTexture.clone();
+                skyboxMaterial.reflectionTexture = environmentTexture.clone();
                 if (skyboxMaterial.reflectionTexture) {
                     skyboxMaterial.reflectionTexture.coordinatesMode = Texture.SKYBOX_MODE;
                 }