public bool FirstPointIsInsideFace(
            CurveLoop CL,
            PlanarFace PFace)
        {
            Transform Trans = PFace.ComputeDerivatives(
                new UV(0, 0));

            if (CL.Count() == 0)
            {
                return(false);
            }
            XYZ Pt = Trans.Inverse.OfPoint(
                CL.ToList()[0].GetEndPoint(0));
            IntersectionResult Res = null;
            bool outval            = PFace.IsInside(
                new UV(Pt.X, Pt.Y), out Res);

            return(outval);
        }