private void CreateVertexDeclarations()
{
var inputElements = mBufferBindings
.Where(binding => binding.Description.Usage != GraphicStreamUsage.Index)
.Select((binding, index) => binding.DowncastTo<XnaBufferBinding>()
.CreateInputElement(index))
.ToArray();
mVertexDeclaration = new VertexDeclaration(mDevice, inputElements);
}