SubD holes behaviour (Quad remesh bug?)


i’m testing Sub-D improvements and i’ve just found this, not sure if it’s a bug or something from my model

i’m trying to convert this polysrf and i don’t find a way to keep aproximately the hole shape

I don’t know why it seems to work on other holes from the same model

Thanks in advance

subD modeling is all about topology.
here’s a basic idea:

but it’ll be a while before rhino has tools for efficient work flow.
(it has a great start ! )


i know subD is about topoly, i showed an example of Quad remesh solution converting a polysrf as seen on a recent video plubished on the blog. Both holes were from the same polysrf.

I also agree with you this tools look promising!!

Hi @nachetz Try the guide curves option, you can select the surface edges around the hole.

In your example it appears you need to give the tool more faces to work with (increase target quad count) or increase Adaptive Size to focus the quads more in the areas of curvature since this hole is part of a much larger object or , as @BrianJ noted, provide guide curves to specify exactly where you want to influence vs spreading the distribution out evenly.

If the target quad count is too low, you will almost always have areas of detail that are sacrificed in order to meet the goal more closely.

Here you can see a smaller scale example of how the number of faces will produce different results.

If high curvature without regard for polycount is the intended desire then increasing Adaptive Size to 100% and enabling Adaptive Quad Count will allow the tool to focus all efforts on curvature and add additional polys where it wants.

If hard edges are acceptable, they can often reduce the polycount totals.

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if you play around w settings a bit, (adaptive size, symmetry, etc.,)
you can get really great results at low poly count !
I’m impressed & looking fwd to further dev of this tool ; )

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First of all, thanks for answering @BrianJ @Trav !

i’m not if it’s a bug or something related to my polysrf: it has 3 holes. The bigger (in the middle) works great, i’ve issues on the two from the legs

i’ve tried as you told me guide curves and it gets better but still seems a bit strange the solution. If i try a polysrf with one hole (or some simmilar) it works like a charm.

Anyway this developing line is awsome … i love it!

p.d. this last image is a test without this problematic holes

That small detail edge will probably make the needed quad count very high to capture it. If you can upload that part of the model I can take a look. Another approach would be to cut the circular hole after you create the SubD using a circle and Wirecut. This will create a polysurface from the subd but will give you a perfect circle.

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Wire cut option worked really well, the model is completely finished, ready to Vray. The polysrf created is a bit heavy…

Anyway here you are the original polysrf before Quad Remesh.
chair_structure.3dm (240.8 KB)
Thanks a lot for your help