[Bug Report]: Exporting Certain Models Flips some Face Normals

[Bobb11881]

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• I have reviewed existing issues on this repository and my issue is not currently reported.
• I have ensured I am on the latest version of the current build of the addon I am using.

Which version of the SAIO are you using?

Release

Please provide details regarding the bug you have encountered

Some models (that I got from GameBanana) keep having their face normals flipped when I export them. This may be why the face normals were incorrect in the first place. Attached is one of the models this happens with. It's BadMeetsEvil's "Cool Sonic".

Please provide the version of Blender that you are currently using when getting this bug.

Blender 4.3.2

Please select your Operating System.

Windows

Operation System Information

Windows 11

Additional Information

I wanted to attach the model or Blender file, but Github doesn't seem to allow that. I'll drop the whole mod zip in instead.

cool_sonic-20250213t133343z-001.zip

[ItsEasyActually]

Apologies for the very late reply on this.

There was an issue where normals could be incorrect on export, but that was resolved in 2.2.0. If your addon wasn't updated to this version, that may be the issue you're experiencing.

If you are on 2.2.0, the issue is the model itself unfortunately. It has overlapping geometry that can (and probably will) cause issues on export.

Using the body as an example:

On import, it looks like this which has incorrect normals:

After correcting the normals using the Alt+N>Recalculate Outside, it looks like this:

The model has custom split normals, and you can remove those in the Data Tab>Geometry Data, and click Clear Custom Normals. The model will then look like this:

The dark areas that exist now are due to the geometry having overlaps due to vertices being internal. This may or may not cause issues with normals on export, and they should be cleaned up properly before re-exporting to ensure the export is correct. The circled vertices are the issue with the body:

The shoes also have issues like this which would need to be fixed, and while the head doesn't have any dark areas on it, it seems there may be some issues with it as well.