Model parts are moved a bit after upload

hi guys, I have some weird error on upload from 3d max and blender, after upload models are moved a bit from each other do you have any solution for that ? I`m talking about this model https://sketchfab.com/3d-models/vr-art-gallery-2020-l-baked-max-scene-77b8c81fd81f43e69e9abf9beceb4d2b(edytowane)

Sketchfab

Hmmm… Strange. You are not using any displacement map are you?

No there is no displacment map, also model exported to glb on online gltf-viewer looks fine but on sketchfab model elements are still moved :frowning:

You give me an idea with this displacement, so I prepared some maps and with their help I moved parts of the model: P Unfortunately, it is not a perfect solution

Hey Lubus, the model is no longer online. Which app did you use and how did you upload it? I wonder if this could be due to vertex compression on our end?

CC @norgeotloic @waleguene

This is the actual model VR Art Gallery 2020 L Baked + Max Scene - Buy Royalty Free 3D model by Marcin Lubecki (@Lubus) [77b8c81] - Sketchfab Store
Right now I`ve used displacment to move a bit parts but without that it looks wrong, floor is still moved a bit.

I’m reprocessing the model with no vertex compression. I’m hoping that will fix it.

Yep, it seems ok now. I suspect it’s a precision issue in vertex positions after compression because the floor is so much bigger relative to the other objects.

Yes, it looks ok now, Thanks for help, any advice how to avoid that in future uploads ?

Not really :confused:

@norgeotloic or @waleguene might have some idea.

I guess it’s caused by the way we compute and align vertex quantization grids.
This compression issue is likely to happen when scene has several geometries with only a few vertices, and where vertex density/dispersion is different from one geometry to another.

Having two geometries with very big faces can easily be affected by slight offsets that are made visible by textures affected by the geometries (AO most of the time)

This is a known issue but unfortunately the fix is tricky here, so we currently disable vertex compression in this case :confused: