> I think it might be a bit too much for Michael to do for V1... or V2 for that matter :S
:) I can definitely say that it's too much for V2 as well. There is still a lot of ground to cover for non-Sub-D NURBS modeling.
It will be quite a ways out before it will be possible for me to work on this type of hybrid functionality for MoI.
> Could you give me a hint where I might find some info on coding
> such a poly sweep function?
Well, some older names for 2-rail sweeping is "birail", so you might do some searching using that term.
"The NURBS Book", by Les Piegl and Wayne Tiller have a section on one-rail sweeping. They give a couple of references:
Sweep surfaces modelling via coordinate transformations and blending :
http://portal.acm.org/citation.cfm?id=87207
V Akman, A Arslan, Sweeping with all graphical ingredients in a topological picturebook, Computers & Graphics 16(3): 273-281 (Fall 1992) [WOS]
Try searching scholar.google.com and ACM for papers about "sweeping".
I think the Hexagon modeler implements these kinds of features for polygon modeling, so you might look over there to see what they have done.
Are you expecting to do this sweep function on polygon line segments, or on curves? Doing it on polygon line segments will probably introduce a lot of different issues because one part of the sweeping function is usually a recursive adaptive fit to the rails, where you start with a coarser version of the sweep and continue to add in points to refine it until it hugs the shape of the rail curves to an acceptable degree. If you want to match polyline rails, it would probably be expected that you would use only those existing segments for your rail curves instead of refitting completely new ones. That introduces a kind of different complication to the whole thing.
In general one of the parts that you will have to solve at first is how to synchronize the point structures of the curves involved.
Sorry I won't able to really help you with this, I just don't have the time available for that type of a thing.
- Michael
