Fix Couples of retention points during dispose

src/Engine/babylon.engine.ts

@@ -5580,7 +5580,7 @@
                 if (this._renderingCanvas) {
                     this._renderingCanvas.removeEventListener("focus", this._onCanvasFocus);
                     this._renderingCanvas.removeEventListener("blur", this._onCanvasBlur);
-                    this._renderingCanvas.removeEventListener("pointerout", this._onCanvasBlur);
+                    this._renderingCanvas.removeEventListener("pointerout", this._onCanvasPointerOut);
 
                     if (!this._doNotHandleContextLost) {
                         this._renderingCanvas.removeEventListener("webglcontextlost", this._onContextLost);
@@ -5622,6 +5622,8 @@
             this._currentBufferPointers = [];
             this._renderingCanvas = null;
             this._currentProgram = null;
+            this._gl = null;
+            this._bindedRenderFunction = null;
 
             this.onResizeObservable.clear();
             this.onCanvasBlurObservable.clear();

src/Materials/Textures/babylon.renderTargetTexture.ts

@@ -759,5 +759,14 @@
                 this._postProcessManager._rebuild();
             }
         }
+
+        /**
+         * Clear the info related to rendering groups preventing retention point in material dispose.
+         */
+        public freeRenderingGroups(): void {
+            if (this._renderingManager) {
+                this._renderingManager.freeRenderingGroups();
+            }
+        }
     }
 }

src/Materials/babylon.material.ts

@@ -1212,6 +1212,7 @@
         public dispose(forceDisposeEffect?: boolean, forceDisposeTextures?: boolean): void {
             // Animations
             this.getScene().stopAnimation(this);
+            this.getScene().resetProcessedMaterials();
 
             // Remove from scene
             var index = this._scene.materials.indexOf(this);

src/Mesh/babylon.abstractMesh.ts

@@ -1333,6 +1333,9 @@
         public dispose(doNotRecurse?: boolean, disposeMaterialAndTextures = false): void {
             var index: number;
 
+            // Smart Array Retainers.
+            this.getScene().resetActiveMeshes();
+
             // Action manager
             if (this.actionManager !== undefined && this.actionManager !== null) {
                 this.actionManager.dispose();

src/Rendering/babylon.renderingManager.ts

@@ -131,14 +131,20 @@
         }
 
         public dispose(): void {
+            this.freeRenderingGroups();
+            this._renderingGroups.length = 0;
+        }
+
+        /**
+         * Clear the info related to rendering groups preventing retention point in material dispose.
+         */
+        public freeRenderingGroups(): void {
             for (let index = RenderingManager.MIN_RENDERINGGROUPS; index < RenderingManager.MAX_RENDERINGGROUPS; index++) {
                 var renderingGroup = this._renderingGroups[index];
                 if (renderingGroup) {
                     renderingGroup.dispose();
                 }
             }
-
-            this._renderingGroups.length = 0;
         }
 
         private _prepareRenderingGroup(renderingGroupId: number): void {

src/babylon.scene.ts

@@ -3170,6 +3170,42 @@
             }
         }
 
+        /**
+         * Clear the processed materials smart array preventing retention point in material dispose.
+         */
+        public resetProcessedMaterials(): void {
+            this._processedMaterials.dispose();
+        }
+
+        /**
+         * Clear the active meshes smart array preventing retention point in mesh dispose.
+         */
+        public resetActiveMeshes(): void {
+            this._activeMeshes.dispose();
+            if (this.activeCamera && this.activeCamera._activeMeshes) {
+                this.activeCamera._activeMeshes.dispose();
+            }
+            if (this.activeCameras) {
+                for (let i = 0; i < this.activeCameras.length; i++) {
+                    let activeCamera = this.activeCameras[i];
+                    if (activeCamera && activeCamera._activeMeshes) {
+                        activeCamera._activeMeshes.dispose();
+                    }
+                }
+            }
+            if (this._renderingManager) {
+                this._renderingManager.freeRenderingGroups();
+            }
+            if (this.textures) {
+                for (let i = 0; i < this.textures.length; i++) {
+                    let texture = this.textures[i];
+                    if (texture && texture.isRenderTarget) {
+                        (<RenderTargetTexture>texture).freeRenderingGroups();
+                    }
+                }
+            }
+        }
+
         public _isInIntermediateRendering(): boolean {
             return this._intermediateRendering
         }