From:  FelixPQ (FELIX)
4123.19 In reply to 4123.18 

many thanks for all this info, especially the layer equivalent in MOI ie. styles and for the info on both version.

I want to mention again that I'm very impressed by MOI. I consider myself to be very newbie at this time and I can only imagine how productive I'll be with more experience.

"But other kinds of calculations like surface intersections or booleans will use numerical techniques that interact directly with the NURBS surface."

Is it the same for sweeps, lofts, etc? I know, I'm a very curious guy and I figure that if some operations are more like math function and others are more of an iterative type, the result of these ops. may differ in relative quality. For example, I notice the 1 rail sweep I used seem to proceed by strait line segment to approximate the curve part of the rail. If this is the case then I would ask is there a way one can "control" the step size or would it preferable to use another operation if possible of course.

I use a join operation on all the surfaces of my shape and MOI reports it's a joined surface and not a solid as I would have expected. Would it be better to use a Boolean union instead?

Another observation, the rails I used are made in 2 parts, a strait line and a some spline I would believe joined together. When I select the original rail it's all selected but when I try to select the edge of the sweep surface, Moi select only a single part at a time. This behavior makes me curious to understand what's going on.