Gets the mesh vertex buffer.
HRESULT GetVertexBuffer( LPDIRECT3DVERTEXBUFFER9 * ppVB );
If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be one of the following: D3DERR_INVALIDCALL, E_OUTOFMEMORY.
This method assumes uniform tessellation.
Header: Declared in D3dx9mesh.h.