public static extern MdlModelStruct *MdlPrimCylinder(IrtVecType *Center, double Radius, double Height, int Rational, CagdPrimCapsType Caps);
public static extern MdlModelStruct *MdlPrimCone2(IrtVecType *Center, double MajorRadius, double MinorRadius, double Height, int Rational, CagdPrimCapsType Caps);