removePlane(plane) {
        if(!this.gl) return;

        // remove from our planes array
        this.planes = this.planes.filter(element => element.uuid !== plane.uuid);

        // remove from scene stacks
        this.scene.removePlane(plane);

        plane = null;

        // clear the buffer to clean scene
        if(this.gl) this.clear();

        // we've removed an object, keep Curtains class in sync with our renderer
        this.onSceneChange();
    }
Removes a Plane element (that has already been disposed) from the scene and the planes array

     params:
     @plane (Plane object): the plane to remove
*