I tried various things to select multiple materials, but nothing worked. Did I miss the way?
At the moment we don't have a feature like this. It could be possible with the API...Could you show me an example that's working as you want but you had to set manually? (i.e. " None of these artifacts are present when I tested Sketchfab's transparency settings " )
Unfortunately, these were not respected on export:( I tried OBJ; looking at all the settings.
What software? We respect the transparency in OBJ's MTL library (both
Also tried FBX, but output exceeded my limit for free account:(
This should work for FBX. I'm not sure of the technical details. Again, what software? You can always compress your models into ZIP/RAR/7z (7z is the best compression), or exclude textures until after upload to save space.
If still too big, there's always the referral program.
Also happy to test a sample FBX if you send it to me.
attempt to achieve the desired transparency using materials with opacity
Looks like you're seeing draw-order problems. Our transparency system isn't quite ready for something like this because we don't use true OIT. That's why you see some geometries that you shouldn't depending on where you're looking.
scene with over 80 materials
You also have some 266 separate geometries/meshes, which hurts performance. Ideally, there would be one mesh per material.
In the 'pruned' version, I think you're still seeing draw-order problems, just to a lesser extent. single-sided vs double-sided rendering might make a difference.