This started in another thread about representing decorative wrought iron.  The modeling and texture creation is fun!    But the hidden line render causes lines that connect edges which should have no connection.  Strangely, the anomaly is much reduced if the textured object is NURBS surface or NURBS shell (objects on right end of the line).  The NURBS surface and subsequent shell were created from the extrude (Extract tool). Some things I tried: Change direction of the 2d p