public static extern CagdCrvStruct *TrngCrvFromTriSrf(TrngTriangSrfStruct *TriSrf, double t, TrngTriSrfDirType Dir);
public static extern TrngTriangSrfStruct *TrngBspTriSrfDerive(TrngTriangSrfStruct *TriSrf, TrngTriSrfDirType Dir);