Exporting a simple cube to *.OBJ and lots of materials and textures?

[gaba]

I'm increasingly posting simplified 3D building models on my websites using ThreeJS.
I don't understand why ArchiCAD26, while exporting a simple cube model from the 3D window to an OBJ file, simultaneously exports so many materials that are not present in the model at all.
Example results of exporting a regular mesh cube:

file.obj (model geometry - simple mesh cube):
1 usemtl (only ONE material !!!)

file.mtl (material definitions):
133 newmtl ( 133 materials !? )
50 textures ( 50 textures !? )

What's the point of exporting so many materials (133!) and textures (50!) unrelated to the model ?

[gmassmann]

hey there gaba,

looks like a bug to me. When I start with a fresh new Archicad I got an OBJ surface folder with the exact 4 surfaces that I have assigned. Then l used a slab and another wall and deleted these objects and now I get these surfaces as well in the  surface folder. I guess that Archicad exports all surface that have been used at some point in the project file. That should be reported to the support team.

[gaba]

Using the procedure: Graphisoft Community (INT) - Knowledge Base - Our Community > How do I get support?

on 2023-08-10 I reported the problem to local support.

As a reminder: in ArchiCAD 27 3001 POL FULL the same problem still occurs when exporting to the OBJ format.