Exporting .obj results in 2 objects that don't show material

I am exporting a bunch of geometry with textures as .obj to be used in another tool.

For the life of me I can not figure out why always 2 objects (not always the same objects) don’t show any materials. Also if you open the .obj in the default windows viewer those 2 objects are shown in black, everything else in the standard white.

Tried unifying mesh normals, but that doesn’t help. All the objects are simple mesh geometry.

Can anyone figure out what is going on?

Here is the model in Rhino:

Then I export as .obj using standard settings. The exported object in the MS viewer:

Importing the .obj again into Rhino. 2 objects don’t show materials, even though they have a material applied:

I don’t get it.

220516_Gallery_16Sculptures_Meshes_walls8.obj (512.8 KB)
220516_Gallery_16 Sculptures_min.3dm (12.5 MB)

Hello- I see that - I’ll see if I can figure out what is wrong.

Exported texture coordinates seem a little supect to me, so far…
RH-68687 Obj export and texture coordinates

-Pascal

@seltzdesign - see https://mcneel.myjetbrains.com/youtrack/issue/RH-68687 for a comment from the developer. It looks like the fix is to remove the opacity maps for the concrete materials, probably not useful in this case) or set the repeat to 1.0 (currently 0.0, I am not sure what that means, even)

-Pascal