topic Re: Degenerated Polygons? Everywhere! in Modeling

Degenerated Polygons? Everywhere!

Patrick M — Tue, 19 Mar 2024 00:36:10 GMT

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?

Operating system used: Mac Apple Silicon Sonoma

Re: Degenerated Polygons? Everywhere!

Barry Kelly — Thu, 14 Mar 2024 05:37:53 GMT

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.

Re: Degenerated Polygons? Everywhere!

runxel — Thu, 14 Mar 2024 16:14:43 GMT

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.

Re: Degenerated Polygons? Everywhere!

Barry Kelly — Fri, 15 Mar 2024 00:56:55 GMT

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.

Re: Degenerated Polygons? Everywhere!

Lingwisyer — Fri, 15 Mar 2024 02:20:56 GMT

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.

Re: Degenerated Polygons? Everywhere!

MASz — Fri, 15 Mar 2024 02:38:36 GMT

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.

Re: Degenerated Polygons? Everywhere!

Patrick M — Fri, 15 Mar 2024 16:27:02 GMT

these are definitely more than 3mm

Re: Degenerated Polygons? Everywhere!

Patrick M — Fri, 15 Mar 2024 16:27:41 GMT

that appears to be the ticket. so maybe another "wish"? can we get custom profiles that work?

Re: Degenerated Polygons? Everywhere!

Patrick M — Fri, 15 Mar 2024 16:31:08 GMT

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

Re: Degenerated Polygons? Everywhere!

Barry Kelly — Sat, 16 Mar 2024 07:33:24 GMT

@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.

Re: Degenerated Polygons? Everywhere!

Lingwisyer — Mon, 18 Mar 2024 01:35:12 GMT

If an extra edge is not an issue, adding an extra node along the curve may resolve it.

Re: Degenerated Polygons? Everywhere!

Patrick M — Thu, 21 Mar 2024 15:14:03 GMT

I'll give that a try; not holding my breath.
I also do not think this report is a factor in file performance. There are MEP degenerated polygons that are triggering crashes, but this particular profile (and session report error) has been in this file for years

But I'll see if an extra node on the profile clears it from the report... good suggestion!

Re: Degenerated Polygons? Everywhere!

runxel — Thu, 21 Mar 2024 16:48:27 GMT

Coincidentally I've found some corrupted profiles in my template file today (contour lines could not be overriden) and the only solution was to redraw everything – like completely, not just putting a node somewhere or whatever. (The node still might help since it fixes the small radius)

But yeah, there might be some underlying issue in any case that is not resolved by "Open & repair" either.

Re: Degenerated Polygons? Everywhere!

Patrick M — Thu, 28 Mar 2024 17:40:39 GMT

different project, different profile, no curves, same warning: "degenerated polygons".
these are literally just a few squares and a couple L shaped fills. No curves, no extra nodes, nothing tricky. Beams they are applied to have no slope, angle, taper or rotation setting... so is this a complex profile issue? what gives? I'm seeing basically any file using complex profiles getting more and more degenerated polygons and session report warnings (which is every file I'm managing).

Re: Degenerated Polygons? Everywhere!

Barry Kelly — Tue, 02 Apr 2024 02:15:34 GMT

Are you sure the degenerated polygons are coming from these complex profiles and not a mesh or slab somewhere?

Or are these complex profile beams/walls interacting with other elements and causing the problems?

Barry.

Re: Degenerated Polygons? Everywhere!

Patrick M — Tue, 02 Apr 2024 15:33:16 GMT

Barry,

Even when I pull them away from the model, their unique ID's are still being reported. It does seem prevalent where beams are intersecting with beams... but if we can only use complex profiles where model elements do not intersect, what is the point of them?
The above (most recent) example could have been modeled with 4 slabs or 2 slabs and an SEO; but that would have been tedious to maintain and to model in the first place. I'll try copying a single beam with that profile to a separate blank file as a test; but the fact that the unique ID being identified are these beams with complex profiles (seemingly any profile some times) is a bit concerning.
I'd think it's something to do with the fill thickness, but these are 1/8" min. thicknesses. If AC can't model/document elements less than 1/8" thickness in a complex profile, the tool needs to be revisited and maybe rebuilt. We are often times designing things to align and flush to finish to a 1/32" tollerance

Re: Degenerated Polygons? Everywhere!

Patrick M — Wed, 07 May 2025 02:49:59 GMT

gonna give this a bump... because if this is supposed to be ****ed up, maybe make it so it isn't?

Re: Degenerated Polygons? Everywhere!

Barry Kelly — Wed, 07 May 2025 03:06:53 GMT

Obviously not exactly the same profile, but this has no issues.

Maybe you can export that profile attribute and attach it here (will have to ZIP the file I think).

Barry.