Nurb to Poly Conversion Problems?

[3dgeek]

Hey everyone, I am having a problem that I'm sure someone else has had to deal with at some point.

I am trying to convert IGES files from Catia v.4 to .OBJ files. I can convert them and sometimes even get a relatively clean mesh, but that is not the norm....

The problem I am running into is in my conversion from Nurbs to Polygons - I get alot of "holes" that are the RESULT of the polys not lining up correctly. The vertices are not lined up...does that make sense? The polys are not overlapping (like sitting on top) each other, but in another sense they ARE overlapping - they don't flow at all. They look like patches of poly's just like the nurbs patches. In these places where the mesh doesn't flow (which is really bad on some parts) there are seams/holes that are quite visible.

Is there some way to correct these surfaces without manually sitting at Modeler splitting poly's and welding. I have hundreds of parts to do this to.

Does anyone have a cure for my detatched poly's?

Thanks alot for any help you genius' can provide.

3dgeek

[Mylenium]

Well, from what you tell I guess it has to do with the parametrization of the NURBS. What you describe sometimes happens if there are uneven numbers of CVs or even overlapping CVs. If would use Maya, there would be a workaround by using different tesselation methods like chord height etc.. This will create tons of triangles so this may not be an option for clean modelling. Also it seems you are after strict UV parametrization for clean rows and columns.... If you are using Rhino or Maya you could also try to use the rebuild surface tools to get patches more suited to your needs.

- End of message. No more ideas. -

Mylenium