See this image of my heli-backpack. The top of the backpack box and the rotor shaft casing join without any real rounding. But in the rotor shaft there is one line of edges parallel to the join, and another in the top of the backpack box. That restricts automatic smoothing on render to a narrow zone around the join, as in the next image. The result looks reasonably like a rounded "fillet" inserted in the join.

Message edited on: 04/09/2005 12:53