Incorrect import result for quantized model by gltfpack

[wayne-wu]

I'm trying to get UnityGLTF to work with files compressed using gltfpack but have been getting incorrect results.

For example, this rigged character does not get imported correctly after running gltfpack whereas both gltf Viewer and gltFast import the model correctly before and after quantization. Even something as simple as the Avocado has different results before and after quantization.

UnityGLTF (Original)	UnityGLTF (Quantized)	gltFast (Quantized)

I'm guessing it has something to do with quantization and the extra node transform that's applied by gltfpack, but I can't be sure yet. If I run gltfpack with -noq (disable quantization) then it imports fine.

Unity Version: 2021.3.31f1
UnityGLTF Version: 2.9.0-rc

Any insights would be appreciated!

[hybridherbst]

Thanks for the report! cc @pfcDorn, would be great if you take a look.

When you drag the UnityGLTF (quantized) import into the scene, does the model show up? I remember there being an issue about the bounds of models being incorrect in some cases, which breaks Unity's model preview, but doesn't actually break the imported model.

[pfcDorn]

I guess you are right. Mesh is there, but it get not rendered. But also not in Scene view. I will take a closer look

[pfcDorn]

hm...it seems to be more an scale issue here. When i set the import scale to 65000, then it has the same size as the gltfast import. So maybe it's a quantization issue here

[pfcDorn]

I have fixed it :)
There was just missing some checks if the quantized data should be normalized or not

[hybridherbst]

Please only close PRs when the fix has actually landed in a release!