NURBS -> Quads

Replies to This Discussion

Permalink Reply by Daniel Piker on April 8, 2013 at 6:10am

There's no really easy way of doing this in a completely automated way...

One approach described here is to generate a vector field on a branched covering of the surface, then split it with a Hodge decomposition, then you can get a parametrization which you can contour in the U and V directions...

There's also a very nice presentation here on different approaches to quad remeshing

I tried a few experiments with the shrink-wrapping approach in Kangaroo, but depending on the complexity of the surface, manually modelling the initial coarse quad mesh can be tricky

Permalink Reply by reverseengineer on April 8, 2013 at 6:14am

No you read the topic wrong way! I asked NURBS surface. Not triangle mesh to quad :D

Permalink Reply by Daniel Piker on April 8, 2013 at 6:30am

It depends on your polysurface, and how the trims are oriented...

If the surfaces were all untrimmed then you could use the isolines to make a mesh relatively easily. Or if the trim lines were on (or very close to) isolines, then you could maybe tweak them to turn your trimmed patches into untrimmed ones

...but for a general polysurf with trimmed patches, you no longer have nice matching NURBS isolines, so you are in about the same situation as if you had a tri mesh, hence my response above.

Perhaps there would be a way to apply a quad mesh to the trimmed patches, then do some special vertex matching along the seams, but I imagine doing this neatly with only quads would be rather difficult.

Permalink Reply by reverseengineer on April 8, 2013 at 6:32am

Can't it be done via normals? Its how retopology programs work?