topic Re: Wall edge is not showing up in Modeling

Wall edge is not showing up

Superswabey — Fri, 31 Jul 2026 05:41:53 GMT

Can someone help me with this, the edge at the intersection between the walls and column is not showing. This happens at various parts of my model. I attached the plan and 3d view for referenece. TIA

Operating system used: Windows

Re: Wall edge is not showing up

Barry Kelly — Fri, 31 Jul 2026 06:24:02 GMT

The side of the wall and column are perfectly in the same plane.

As they have the same surface material, the joining line will be eliminated automatically.

Actually it seems just turning off the edge surface override for just the column is enough to get the joining line back.

Even the the walls and column still have the same surface material.

Barry.

Re: Wall edge is not showing up

Superswabey — Fri, 31 Jul 2026 07:04:53 GMT

Thank you. So it is not possible to have a "clean" joining if i want the surfaces to be the same.

Re: Wall edge is not showing up

Barry Kelly — Fri, 31 Jul 2026 07:30:49 GMT

If surfaces are co-planer and they are the same surface material, then the join between then will disappear automatically.

That is why I was bit surprised that simply overriding the column edge surface, with the same surface material, made the join show.

But if you override the edge surface of both the wall and the column with the same surface, the join disappears again as it should.

It seems columns and walls behave a little strangely.

It is quite common to duplicate a surface material but give it a different name.

In my case it would be "paint wall 1" and "pant wall 2".

Both exactly the same surface material in appearance, but as they are separate attributes, Archicad considers them as different materials, and the joins between them will always show.

That is not what I have shown here though, all surfaces are exactly the same attribute.

Barry.

Re: Wall edge is not showing up

Superswabey — Fri, 31 Jul 2026 07:36:21 GMT

I see now. Thank you for the clear explanation!

Re: Wall edge is not showing up

Stefan L_ — Sat, 01 Aug 2026 19:02:52 GMT

I feel obliged to point out that - in this situation - Archicad doesn't work as it should.

The edge does not disappear because someone (Graphisoft or we users) wants it to disappear, but it happens nonetheless.

Barry's finding is interesting although I can't reproduce it...

@Barry Kelly schrieb:

... simply overriding the column edge surface, with the same surface material, made the join show.

I'd suspect that ACs "show/hide edge algorithm" is forced to check the edges in a different order.

My personal gym 🤓

AC27, left and right are mirrored, otherwise identical, selected elements on the right to show hidden edges.

Only one surface material, only one building material, no error possible (green arrows).

Red wall has a lower junction order than green wall.
> green is protruding and has no edge to show; red has an edge to show (pink arrows).

Top columns (orange outline) have their surface overwritten with the same and one and only existing surface material.

> top column right is last selected element and shown in info bar

Bottom columns (pink outline) have their surface by BM.

No edge for...

Betreff: Wall edge is not showing up

runxel — Fri, 31 Jul 2026 16:02:33 GMT

This is actually a deeper running problem.

I've logged a bug for something that happens even more often than your example, Stefan.

On “T-Sections”, where e.g. a slab and two walls meet (the upper wall starts at the top of the slab) no line will be displayed either:

Happens in both PBR and in (formerly known as) OpenGL.

Interestingly enough in the internal engine everything works as intended:

It's not new in AC30 tho. This has been grinding my gears since... forever? 🤔

Betreff: Wall edge is not showing up

Lingwisyer — Wed, 05 Aug 2026 08:20:48 GMT

Internal engine is not merging identical surfaces as visible on the side contour.

Being more generic, the engine detects coplanar identical surfaces and excudes the contour there even if said coplanar surfaces are not visible. Slab top face merges with the bottom walls top face and the top walls internal face merges with the bottom walls internal face, hence no contour. Same thing with the column and wall. I suspect that the mechanism of exclusion has no way to detect if there are coincident faces involved that should be exluded from the calculation.

Ling.

Re: Wall edge is not showing up

Lingwisyer — Thu, 06 Aug 2026 01:13:04 GMT

A quick test would suggest that it is the coincident faces causing the elimination of contours between visible faces.