Now serialize environment texture

src/Tools/babylon.sceneSerializer.ts

@@ -209,6 +209,11 @@
                 serializationObject.multiMaterials.push(multiMaterial.serialize());
             }
 
+            // Environment texture
+            if (scene.environmentTexture) {
+                serializationObject.environmentTexture = scene.environmentTexture.name;
+            }
+
             // Skeletons
             serializationObject.skeletons = [];
             for (index = 0; index < scene.skeletons.length; index++) {
@@ -219,7 +224,7 @@
             serializationObject.transformNodes = [];
             for (index = 0; index < scene.transformNodes.length; index++) {
                 serializationObject.transformNodes.push(scene.transformNodes[index].serialize());
-            }            
+            }
 
             // Geometries
             serializationObject.geometries = {};