I did not. I don't think I saw a diagonal texture on my model. I'll check again and update the one linked once I get things figured out

Didn't use a wall element. It's all boxes besides the pillows.

Thanks Keet for the very detailed explanation.
I'll give it a try when I'm back home.

I created a sofa model within Sweethome 3D. I used 'copy as new furniture' plugin at the end to merge things together. But I just realized that materials in the model are quite a mess. Is there a way to clean up which things share materials and how they are named? For example the boxes have a ...