Converting polysurfaces to SubD for organic shapes

Rhino SubD
1

Hello Rhino community,

I would like to ask for some help regarding the conversion of polysurfaces into SubD objects. My goal is to achieve an organic SubD result without generating elements that are too thin. It doesn’t matter if the holes get deformed during the conversion, as long as the overall design is preserved.

These parts, even if further refined afterwards, must remain suitable for machining. Since I have more than 40 similar pieces to create, I would like to avoid having to redraw each one manually.

Is there a simple workflow or parameter setting that could help me obtain an acceptable SubD conversion directly from polysurfaces, while keeping the geometry machinable?

Thank you very much for your advice !

example 1, no acceptable at all :

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image1410×811 118 KB

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image1210×987 123 KB

The conversion (yellow = polysurface / red = sub d) above gives the desired design but creates geometries that are too thin.

example 2, a bit more acceptable :

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image1314×657 68.8 KB

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image1180×720 101 KB

Attached below are the 3D file containing 6 polysurfaces to be converted into SubD.

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image1247×809 65.9 KB

3D - POLYSRF TO SUB D - 6.3dm (3.8 MB)

3D - POLYSRF TO SUB D - 5.3dm (3.5 MB)

3D - POLYSRF TO SUB D - 4.3dm (2.5 MB)

3D - POLYSRF TO SUB D - 3.3dm (2.8 MB)

3D - POLYSRF TO SUB D - 2.3dm (18.6 MB)

3D - POLYSRF TO SUB D - 1.3dm (2.8 MB)

2

That’s challenging… you have all objects as polysurfaces and all holes are vertical or in one direction?

3

can you do this as a single surface thickness subd to start and offset it after the conversion?

that’s my go to method for thin stuff.

4

you could also shrinkwrap this with a larger edge length.. and a higher smoothing value. that would help eliminate the thin bits. you could then quadremesh>tosubd>

can you machine a mesh? If so Shrinkwrap may be the way to go and end up with a mesh result instead of subd.