/// <summary>
 /// Get the deferred face.
 /// </summary>
 /// <returns></returns>
 public DeferredFace GetDeferredFace()
 {
     return(_deferredFaceStack.Count != 0 ? _deferredFaceStack.Pop() : new DeferredFace());
 }
 /// <summary>
 /// Get a store index buffer or create a new instance.
 /// </summary>
 /// <returns></returns>
 public IndexBuffer GetVertexBuffer()
 {
     return(_emptyBufferStack.Count != 0 ? _emptyBufferStack.Pop() : new IndexBuffer());
 }