Degenerated Surfaces


I get degenerated bezier surfaces in my meshing because of having triangular patches in rhino model. For my solver, I need all my beziers be quadrilateral and can’t read triangular ones. So, it generates degenerated beziers in reading the model and effects my results very badly. Is there any way to convert those degenerated beziers to quadrilateral ones? Thanks

Just a quick comment for my implementation.

To find out which beziers are problematic, when I am reading the geometry I check singularity of the sides of each bezier using bezier.Issingular(0-4)! Then, I need a way to create quadrilateral beziers manually.

Something like this. Is it possible to do in OpenNURBS? Thanks

Hi @Omid1,

If the singular surface is planar, then you should be able to calculate the need points to create a quad surfaces you are looking for.

Use a function like this to make your planar surface.


If the singular surface is not planar, then there might not be enough in the free openNURBS toolkit to help.

– Dale

Hi @dale

Thanks for the comment!

– Omid