FBX Exporter: "Export Subdivision Surface" state inverted #105459

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SpookyDoom · 2024-09-16T14:39:11+02:00

SpookyDoom commented

2024-09-16 14:39:11 +02:00

System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: Quadro P2000/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 537.58

Blender Version
Broken: version: 4.2.0, branch: blender-v4.2-release, commit date: 2024-07-16 06:20, hash: a51f293548ad
Worked: (newest version of Blender that worked as expected)

Addon Information
Name: FBX format 5.12.4
Author: Campbell Barton, Bastien Montagne, Jens Restemeier, @Mysteryem

Short description of error
Operator Presets > Geometry > Export Subdivision Surface seems to be worded either wrong or inverted.
When activating "Export Subdivision Surface", the exported meshes all have no subdivision surface applied.
Inversely, when deactivated, the Subdivision Surface Modifier seems to be baked into the meshes on export.

Exact steps for others to reproduce the error
In the .blend file provided the same Mesh Setup has been placed in two collections with FBX exporter Settings.
The Mesh has a mirror modifier as well as a subdivision surface modifier.
If you take a look at the export settings you see that the collection that you would expoect to export the subdivision surfaces ("Export Subdivision Surface" active) does not.
And inversely the one you would expect to ignore any subdivision surface modifiers ("Export Subdivision Surface" deactivated) does export it.

**System Information** Operating system: Windows-10-10.0.19045-SP0 64 Bits Graphics card: Quadro P2000/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 537.58 **Blender Version** Broken: version: 4.2.0, branch: blender-v4.2-release, commit date: 2024-07-16 06:20, hash: `a51f293548ad` Worked: (newest version of Blender that worked as expected) **Addon Information** Name: FBX format 5.12.4 Author: Campbell Barton, Bastien Montagne, Jens Restemeier, @Mysteryem **Short description of error** _Operator Presets > Geometry > Export Subdivision Surface_ seems to be worded either wrong or inverted. When **activating** "Export Subdivision Surface", the exported meshes all have **no subdivision** surface applied. Inversely, when **deactivated**, the Subdivision Surface Modifier seems to be baked into the meshes on export. **Exact steps for others to reproduce the error** In the .blend file provided the same Mesh Setup has been placed in two collections with FBX exporter Settings. The Mesh has a mirror modifier as well as a subdivision surface modifier. If you take a look at the export settings you see that the collection that you would expoect to export the subdivision surfaces ("Export Subdivision Surface" active) does not. And inversely the one you would expect to ignore any subdivision surface modifiers ("Export Subdivision Surface" deactivated) does export it.

ExportSubdiv_Active.blend

886 KiB

SpookyDoom added the

labels 2024-09-16 14:39:12 +02:00

Thomas Barlow commented

2024-09-16 14:58:59 +02:00

Geometry > Export Subdivision Surface saves the first Subdivision Surface modifier as FBX Subdivision without applying it. Applications that support FBX Subdivision can read the FBX Subdivision from the file when importing it and then can apply the subdivision only during rendering or apply it after importing. This allows for files with high subdivision surface levels to be exported without resulting in large file sizes that would occur if the subdivision surface was applied. In Blender's case, importing such a file with Include > Subdivision Data enabled in the importer will create a Subdivision Surface modifier on the imported mesh with the appropriate number of levels.

With Geometry > Export Subdivision Surface disabled and Geometry > Apply Modifiers enabled (enabled by default), all non-Armature modifiers are applied while exporting, baking the results into the exported mesh.

So the behavior seen here is the intended behavior.

`Geometry > Export Subdivision Surface` saves the first Subdivision Surface modifier as _FBX Subdivision_ without applying it. Applications that support _FBX Subdivision_ can read the _FBX Subdivision_ from the file when importing it and then can apply the subdivision only during rendering or apply it after importing. This allows for files with high subdivision surface levels to be exported without resulting in large file sizes that would occur if the subdivision surface was applied. In Blender's case, importing such a file with `Include > Subdivision Data` enabled in the importer will create a Subdivision Surface modifier on the imported mesh with the appropriate number of levels. With `Geometry > Export Subdivision Surface` disabled and `Geometry > Apply Modifiers` enabled (enabled by default), all non-Armature modifiers are applied while exporting, baking the results into the exported mesh. So the behavior seen here is the intended behavior.

SpookyDoom commented

2024-09-16 22:06:41 +02:00

Oof. Yes, okay when you see it from this angle then it's correct bahaviour, I guess.
"Export lowest Subdivision only" could maybe be a bit clearer to the user. The way it is worded now seems too ambiguous to me.

Oof. Yes, okay when you see it from this angle then it's correct bahaviour, I guess. "Export lowest Subdivision only" could maybe be a bit clearer to the user. The way it is worded now seems too ambiguous to me.

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FBX Exporter: "Export Subdivision Surface" state inverted #105459