static Surface FromExtrudedSurface(IList <DB.Curve> curves, DB.BoundingBoxUV bboxUV, double relativeTolerance) { var ctol = relativeTolerance * Revit.ShortCurveTolerance; var axis = new LineCurve ( new Line(curves[0].GetEndPoint(0).ToPoint3d(), curves[1].GetEndPoint(0).ToPoint3d()), 0.0, 1.0 ); Curve curveU = ToRhino(curves[0]); curveU.Translate(axis.PointAt(bboxUV.Min.V) - curveU.PointAtStart); Curve curveV = new LineCurve(new Line(axis.PointAt(bboxUV.Min.V), axis.PointAt(bboxUV.Max.V))); if (ctol != 0.0) { curveU = curveU.Extend(CurveEnd.Both, ctol, CurveExtensionStyle.Smooth); curveV = curveV.Extend(CurveEnd.Both, ctol, CurveExtensionStyle.Smooth); } return(SumSurface.Create(curveU, curveV)); }