Revert some variables to private and add necessary getters.

src/Rendering/babylon.geometryBufferRenderer.ts

@@ -1,14 +1,13 @@
 module BABYLON {
     export class GeometryBufferRenderer {
-        protected _scene: Scene;
-        protected _multiRenderTarget: MultiRenderTarget;
-        protected _effect: Effect;
-        protected _ratio: number;
+        private _scene: Scene;
+        private _multiRenderTarget: MultiRenderTarget;
+        private _ratio: number;
+        private _enablePosition: boolean = false;
 
+        protected _effect: Effect;
         protected _cachedDefines: string;
 
-        protected _enablePosition: boolean = false;
-
         public set renderList(meshes: Mesh[]) {
             this._multiRenderTarget.renderList = meshes;
         }
@@ -27,6 +26,14 @@ module BABYLON {
             this._createRenderTargets();
         }
 
+        public get scene(): Scene {
+            return this._scene;
+        }
+
+        public get ratio(): number {
+            return this._ratio
+        }
+
         constructor(scene: Scene, ratio: number = 1) {
             this._scene = scene;
             this._ratio = ratio;