HRESULT SetPlane(D3DVALUE rvLeft, D3DVALUE rvRight, D3DVALUE rvBottom,
D3DVALUE rvTop);
Sets the front clipping plane of the viewing frustum by supplying the coordinates of the four sides, relative to the camera's z-axis.
·Returns D3DRM_OK if successful, or an error otherwise. For a list of possible return codes, see Direct3D Retained-Mode Return Values.
rvLeft, rvRight, rvBottom, and rvTop
New front clipping plane.