http://msdn.microsoft.com/en-us/library/bb173463(v=vs.85).aspx
IDirect3DDevice9 :: SetRenderState方法来设置从的D3DRS_VERTEXBLEND渲染状态值D3DVERTEXBLENDFLAGS枚举
http://msdn.microsoft.com/en-us/library/bb173463(v=vs.85).aspx
IDirect3DDevice9 :: SetRenderState方法来设置从的D3DRS_VERTEXBLEND渲染状态值D3DVERTEXBLENDFLAGS枚举