internal Curve Curve(double tol) { Curve c = AxisCurve.Curve(tol); if (c == null) { return(null); } IfcGrid grid = mPartOfU; if (grid == null) { grid = mPartOfV; } if (grid == null) { grid = mPartOfW; } if (grid != null) { c.Transform(grid.PlacementTransform()); } return(c); }