Mesh weld (or subd-join) in grasshopper for subd with N-gons needed

What is the status of mesh weld for subd currently? I want to use it for subd to make radial symmetrical objects using gh. Thing is with N-gons, using meshweld converts these to triangles. We need a way to join subds like in Rhino (Join with Smooth=yes)

Works for me like a sequence below, but I think what you want is to skip completely meshing part and work only with SubD.

  1. I convert SubD to Nurbs.
  2. Then Nurbs to Mesh.
  3. Then Explode Mesh
  4. Then Reference it to Grasshopper and using “From Mesh Component” I create Ngon Mesh that I can weld.

Can you just use quads Mesh faces instead and at the last step convert to SubD?

Hi Petras,

what I mean is if you have a subd shape that has non quad faces (5 or more sided) and you want to make radial copies of it, then join these into a single subd without seams/creases this can’t be done as far as I know currently in gh. The only way I found is by working with meshes, then join the radial copies, then mesh weld and subd. But as stated, the mesh weld will convert these 5 or more sided mesh faces to triangular mesh faces:


without mesh weld no smooth transitions between the joined subds:

why not just fix the topology with an added edge?

Yes in this spot I could probably do that, but there are also cases where 5 or 6 sided faces give me better surface appearance. Here is such an area:

Also there are often area’s where you need to make a choice to go for N-gons or have another ‘starpoint’ to add only local detail. So N-gons are not completely avoidable.
Basically all I ask for is the join command for SubD to become available in Rhino common :wink:

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