/// <summary>
 /// Initializes a new instance of GeometryNode.
 /// </summary>
 public GeometryNode(Renderer renderer, SceneGraph sceneGraph, Matrix localTransform,
     IRenderable renderObject)
     : base(renderer, sceneGraph)
 {
     this.localTransform = localTransform;
     this.renderObject = renderObject;
 }
        /// <summary>
        /// Initializes a new instance of SceneGraphNode.
        /// </summary>
        public SceneGraphNode(Renderer renderer, SceneGraph sceneGraph)
        {
            if (renderer == null)
            {
                Log.Write("Cannot create a SceneGraphNode with a null Renderer reference.");
                throw new ArgumentNullException("renderer",
                    "Cannot create a SceneGraphNode with a null Renderer reference.");
            }

            if (sceneGraph == null)
            {
                Log.Write("Cannot create a SceneGraphNode with a null SceneGraph reference.");
                throw new ArgumentNullException("sceneGraph",
                    "Cannot create a SceneGraphNode with a null SceneGraph reference.");
            }

            this.renderer = renderer;
            this.sceneGraph = sceneGraph;
        }
 /// <summary>
 /// Initializes a new instance of GeometryNode.
 /// </summary>
 public GeometryNode(Renderer renderer, SceneGraph sceneGraph)
     : base(renderer, sceneGraph)
 {
 }