> is there a special setting you used to enable a single-creased-surface result in Rhino? Over here when I do this type of 2-rail >sweep in Rhino, it generates a polysurface split along the kinks, and trying to turn on control points results in a message: Cannot >turn on points for polysurfaces.

Hi Michael. Are you referring to R3 ? In R4, all surfacing commands are able to output a single creased surface (loft, sweep, extrude, etc) unless they require capping to make it a solid (like extruding a planar curve). For example, the cylinder primitive is a polysurface. But you can loft 2 circles and 2 points located at their centers to produce a single surface cylinder, whose points can be turned on. I haven't changed any of my settings in Rhino.


>One thing you might be interested in - the result of this 2 rail sweep in MoI remains point editable despite it being a polysurface. >This is because MoI supports a feature where you can edit the control points of a polysurface if the joined edges of the >polysurface are natural surface edges and have the same control point structure along the joined edge. This is convenient >because the output of surfacing commands with kinked input curves generate such structures. Also for example a simple box is >point editable in MoI.

>- Michael

That's something i remember from a thread a few months ago. It's a really great feature, especially for people who patch model with untrimmed nurbs surfaces for export to animation programs. Or for playing around with architectural ideas, it could be very easy to sketch out a block model in a Frank Gehry style ...

jonah