topic Re: Switching between 3D and 2D Views very slow in Modeling

Switching between 3D and 2D Views very slow

DangCad1 — Tue, 31 Mar 2026 07:39:29 GMT

I’m working in a file where it has suddenly become very slow to switch from 3D to 2D views. The opposite (from 2D to 3D) is not a problem, and once I’m working in 2D everything runs fine. But every time I switch from 3D to 2D, the file takes 40–60 seconds to load, which is not sustainable in the long run.

The file is relatively heavy (756 MB) and contains two meshes and a point cloud. However, none of these are turned on in either the 2D or 3D views I’m switching between.

I feel like the file became slower after I added the mesh, but I’m not entirely sure that’s when it started. As mentioned, these elements are not visible. I’ve also tried deleting the mesh, including its layer, but that didn’t make any difference.

I’ve tried “open and repair,” but that didn’t help either.

Since I’ve signed an NDA for the project, I unfortunately can’t upload the file.

What else can I do to troubleshoot this?

Operating system used: Mac Apple Silicon 26.3.1 Tahoe

Re: Switching between 3D and 2D Views very slow

Barry Kelly — Tue, 31 Mar 2026 08:31:30 GMT

Could it be the Trace & Reference is active when you are switching back to 2D?

If it is active, you are effectively regenerating 2 different floor plans.

If the reference is complicated and has different settings to the actual floor plan, it can sometimes take a little while to generate.

Barry.

Re: Switching between 3D and 2D Views very slow

DangCad1 — Tue, 31 Mar 2026 09:24:41 GMT

Unfortunately not, trace & reference is not active.

Re: Switching between 3D and 2D Views very slow

JP_ — Fri, 17 Apr 2026 06:18:33 GMT

Having the same issue on Mac in ArchiCAD 28. Happened suddenly whilst working in the file and occurs in both directions i.e. going from 2D to 3D and vice versa. It's taking longer than 40-60 seconds - likely three times longer. The file is much smaller (250Mb) and was working just fine up until it wasn't. There was a point cloud object loaded to the Embedded Library but that was impractical to use so was deleted from the file altogether. Open and repair did nothing, either. The issue is with the file as I made a copy from our server onto the desktop to test and had the same problem. Looking forward to hearing from someone with a reason and solution! Thanks in advance.

Immediate update:
The point cloud object was apparently not removed from the Embedded Library. Once deleted (again) the file has resumed normal service. An unused object in the Library should not slow down the entire file though. Something to look into, perhaps

Re: Switching between 3D and 2D Views very slow

Benedek Gaszpor — Wed, 22 Apr 2026 11:02:10 GMT

Hi All!

Some other things to consider, regarding slow 2D-3D opening. (Based on extensive empirical data and sleepless nights wondering what the heck is going on with our own projects...)

Check the layer visibility AND the layer intersection numbers relating to the view you wish to open. If it has a "Custom" indication for the layer combination, there might be an issue. If you have elements hidden on non-visible layers, Archicad still calculates with them, unless the layer intersection number is set to 0.
Common issues for 2D floorplans; You let the software calculate the intersections between elements that are irrelevant for the given view. For example (something that we have messed up in our workflow for quite a while until we found it), you have the columns' and slabs' layers on the same intersection number, thus the computer calculates all slab-columns intersection... But in reality these are irrelevant to you on a floor plan. Same goes for the beam-column intersections.
The mesh tool can majorly mess up the 3D and the section view generations. Especially if you have a very variable terrain mesh. And if you use a lot of SEOs on it that can kill the memory usage too.
I've found that one of the good workarounds for cut-outs from the terrain, is to modell a separate SEO operator instead of using the modelled foundations and other building parts that are underground. Of course this means that when you change the foundation for example you have to update the operator geometry as well. Also when using SEOs it is best to use the simple cut, and not the cut with everything above / below. The simple cut uses less computational process, thus making the view generation faster.

Hope this can help a bit too. 🙂

Cheers!

Re: Switching between 3D and 2D Views very slow

Laszlo Nagy — Sun, 26 Apr 2026 13:30:35 GMT

@Benedek Gaszpor wrote:

Check the layer visibility AND the layer intersection numbers relating to the view you wish to open. If it has a "Custom" indication for the layer combination, there might be an issue. If you have elements hidden on non-visible layers, Archicad still calculates with them, unless the layer intersection group number is set to 0.
Common issues for 2D floor plans; You let the software calculate the intersections between elements that are irrelevant for the given view. For example (something that we have messed up in our workflow for quite a while until we found it), you have the columns' and slabs' layers on the same intersection number, thus the computer calculates all slab-columns intersection... But in reality these are irrelevant to you on a floor plan. Same goes for the beam-column intersections.

This is actually something we teach on the BIM Manager Program: Go through all your Layer Combinations, and make sure that all hidden Layers have their Layer Intersection Group Number set to 0.