Returns the normal vector at the specified parameter location ([u, v]).
Parameters
Parameters
Description
dU
[in] u parameter.
dV
[in] v parameter.
normal
[out] A passed-in parameter for returning the normal vector.
Returns
Returns eOk if successful. If the surface doesn't contain any NURBS information, returns eFail. If the dU or dV values are invalid, returns eOutOfRange.