How to connect two subd surfaces

Hi everyone,

I have two complex subd surface that I want to turn it into a wall. I have tried doing subd sweep 2 rails on the subd edge curves and joining them, but when I did the analysis, it shows that there’s naked edges. I tried doing bridge but it says I don’t have the same matching edges. How do I make this a closed geometry because I need to use this geometry to boolean difference a floor slab. I will also attach this file below. Any help would be great! Thank you!



subd surface fragment.3dm (1.6 MB)

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I’ve been playing around with this, attempting to close up the gap, but noticed the curves I was making from the edges were ‘closed’ curves when they shouldn’t have been, so this makes me think something weird is happening with your sub-d’s.

They might be overlapping onto them selves or something. Idk, I’m still checking it out.

I noticed a spot where there’s self intersection:

I was able to do some tricks:

subd surface fragment_emod.3dm (11.0 MB)

There’s a couple anomalies, but I’m not sure what the intent is behind the selfintersection for example.

There’s other ways to do it more accurately but would take more time, depending on necessity.

On the sides I just decided to patch them and use trimmed surfaces, then converted it all to polysrfs, then remeshed it back to sub-d.

I couldv’e spent several hrs stiching the thing together without changing the original subd’s but it all depends on intent and I usually shoot for a compromise experiment in the beginning.

It all depends on the direction one might go. Can always do another experiment later.


try this sequence, Shrinkwrap function first, and then QuadRemesh

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Thank you so much for replying!

Ideally the two surface shouldn’t have any selfintersection but because I wanted to create a wall with the thickness of around 300mm, it meant that at some places it would intersect at bit.

Could you please upload the file as rhino 7 file? I’m on student license and don’t have access to rhino 8 yet :frowning:

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Thanks for replying!

Is it possible for the edges to be sharp corners?

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Some manual work, but you can do everything in less 5 minutes:
Bridge only the 4 corners:

then use _Fill command with “Triangulated” option on the 4 holes:

manually sub-select the unwanted edges

and delete them

(Alternatively, you can use ExtractControlPolygon to get the equivalent mesh, use “QuadrangulateMesh” command, and then convert it back to SubD…)

Manually re-add the crease edges:

Nothing to say about the two shells intersecting each-other … you know how you did it…


I really like your approach :beers: I would have really wanted to do it this way but didn’t know the perfect workflow at the time :smiley:

I’m still not 100% fluent in the sub-D format, so alot of what I do is just using the remeshing tool :joy:

subd surface fragment_emod_v7.3dm (10.8 MB)

If you use @maje90 's workflow you could most likely get a more accurate result.

The workflow I used, may have caused at least one generation of error deviation, for example when I did a remeshing.

But ultimately depends on desired results etc.

Thank u it works!

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thank u!

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