Degenerated Polygons? Everywhere!
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2024-03-14
06:15 AM
- last edited on
2024-03-19
01:36 AM
by
Laszlo Nagy
Can someone please explain to me why custom profile beams almost always have "degenerated polygons"? This session report comes up any time a project uses custom profiles. It's a very simple profile with about 7 nodes and a curved edge. The beam settings do not have any additional modifiers, it is not stretched in any way. There has to be something I'm missing, but I've done everything I can think of to fix files with degenerated polygons in the beams and I'm coming up empty. Anyone at GS here can shed light on it?
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2024-03-14 06:37 AM
I have no idea, but if I was to guess, I would suspect that tiny curved end.
Does the same error happen if you make it straight?
Barry.
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2024-03-14 06:37 AM
I have no idea, but if I was to guess, I would suspect that tiny curved end.
Does the same error happen if you make it straight?
Barry.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11

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2024-03-14 05:14 PM
How thick is the thinnest part of yours?
After long discussions with the support some time ago I was told that one should not put details smaller than 3 mm in the profile, because they would inevitably create those degenerations.
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2024-03-15 01:56 AM - edited 2024-03-15 01:56 AM
I have successfully used fills 1mm thick in profiles (for sheet steel) but the ends have always been square.
Larger curves seem OK.
I think the profiler may have trouble with smaller curves.
Barry.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11

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2024-03-15 03:20 AM
My guess is it is due to how AC simplifies curved complex profiles and how the curve resolution is hardcoded...
I was modelling taps recently and had to intentionally create large facetted curves to scale down in order to get any decent looking curves... Said facets come edges were removed after morph conversion.
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2024-03-15 03:37 AM - edited 2024-03-15 03:38 AM
Something I've been complaining to Graphisoft about for years. It usually goes ignored. Therefore, I have to rely on workarounds such as:
- Draw/import the profile in Rhino.
-
Divide and shatter curve using Grasshopper script.
-
Export as dwg.
-
Merge in Archicad.
-
Use magic wand to create fill for complex profile.
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2024-03-15 05:27 PM
these are definitely more than 3mm
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2024-03-15 05:27 PM
that appears to be the ticket. so maybe another "wish"? can we get custom profiles that work?
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2024-03-15 05:31 PM
I accepted a solution, but this is obviously not a solved issue. Archicad should be able to model curved ends/noses in custom profiles. The fact that it does, but reports it as an error is NOT a solution

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2024-03-16 08:33 AM
@Patrick M wrote:
I accepted a solution, but this is obviously not a solved issue. Archicad should be able to model curved ends/noses in custom profiles. The fact that it does, but reports it as an error is NOT a solution
You can un-mark it as a solution if you want - just go to the three dots (option) at the side of the post.
Or I can un-mark it.
So, if you remove that little curved end, you don't get any errors?
What is the radius of that curve - I will try to replicate.
Barry.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11