Export FBX with 2or more same materials on an object #104665

New Issue

Sergei Sobolev · 2023-06-02T13:35:11+02:00

Sergei Sobolev commented

2023-06-02 13:35:11 +02:00

System Information
Operating system: Windows-10-10.0.22621-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 535.98

Blender Version
Broken: version: 3.5.1, branch: blender-v3.5-release, commit date: 2023-04-24 18:11, hash: e1ccd9d4a1d3
Worked: (newest version of Blender that worked as expected)

Short description of error
Export FBX with 2or more same materials on an object. if an object has this case it exports with intermingled materials.
the new version 3.5 has this bug. Previous didn't.

Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]

System Information Operating system: Windows-10-10.0.22621-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 535.98 Blender Version Broken: version: 3.5.1, branch: blender-v3.5-release, commit date: 2023-04-24 18:11, hash: e1ccd9d4a1d3 Worked: (newest version of Blender that worked as expected) Short description of error Export FBX with 2or more same materials on an object. if an object has this case it exports with intermingled materials. the new version 3.5 has this bug. Previous didn't. Exact steps for others to reproduce the error [Please describe the exact steps needed to reproduce the issue] [Based on the default startup or an attached .blend file (as simple as possible)]

22.png

901 KiB

bug 22.blend

90 MiB

Sergei Sobolev added the

labels 2023-06-02 13:35:12 +02:00

Thomas Barlow commented

2023-06-02 18:00:48 +02:00

Caused by myself in 5c9ecad1d2

I couldn't reproduce the issue with only Blender, but I can reproduce the issue with both Unity and FBX Review.

Upon further investigation, the issue of duplicate materials causing material assignments to become offset and go out-of-bounds (#103976) is actually an issue in the FBX Importer, likely caused by 8366db5686.

The previous patch to the exporter should either be reverted or modified to only add the connection if the material is new.

The issue of duplicate materials being assigned to the same material slot on FBX export will still be present either way.

Caused by myself in https://projects.blender.org/blender/blender-addons/commit/5c9ecad1d29edd8ba9ebaaad8f71839bd5d88324 I couldn't reproduce the issue with only Blender, but I _can_ reproduce the issue with both Unity and FBX Review. Upon further investigation, the issue of duplicate materials causing material assignments to become offset and go out-of-bounds (https://projects.blender.org/blender/blender-addons/issues/103976) is actually an issue in the FBX Importer, likely caused by https://projects.blender.org/blender/blender-addons/commit/8366db568607ec20a5f087d3a156d2d4dd4f8f89. The previous patch to the exporter should either be reverted or modified to only add the connection if the material is new. The issue of duplicate materials being assigned to the same material slot on FBX export will still be present either way.

Jesse Yurkovich added

and removed

labels 2023-06-02 22:51:43 +02:00

Thomas Barlow referenced a pull request that will close this issue

2023-06-04 05:39:46 +02:00

Fix #104665: FBX Export: Duplicate materials cause material indices to be offset #104667

Thomas Barlow referenced this issue

2023-06-04 19:44:12 +02:00