3D model looks wrong after usdz auto-conversion

[codedotart]

Hi,

I am working with a chair model and it becomes disfigured when opened in quick look inside ios. You can see it here

https://teal-whip-brie.glitch.me

IOS

Android

Can anyone please help me in resolving this issue?

[elalish]

Yep, this looks like a bug or unsupported feature in USDZExporter. @mrdoob any idea if this is a known issue or not?

To work around issues like this until they're fixed, you can supply your own ios-src.

[mrdoob]

mrdoob/three.js@a40bb1a

[elalish]

@mrdoob Thanks! I wonder if we're getting negative scales from any design software that uses a left-handed coordinate system? Unfortunately there are some major ones, so we may want to consider a work-around where we do the triangle inversion in the export process.

[mrdoob]

I considered doing that but the same geometry may be used by a different mesh.
So I opted for logging a warning for now.

[codedotart]

Great! thanks for the help. We fixed it now. Also, the alpha map is not working on ios ar. Is that something that is not supported yet?

[mrdoob]

mrdoob/three.js#22086