Exporting gltf with draco compression messes up the vertex color #75550

New Issue

Jesper van den Ende · 2020-04-09T14:06:34+02:00

2020-04-09 14:06:34 +02:00

System Information
Operating system: Darwin-19.4.0-x86_64-i386-64bit 64 Bits
Graphics card: AMD Radeon Pro 460 OpenGL Engine ATI Technologies Inc. 4.1 ATI-3.8.24

Blender Version
Broken: version: 2.83 (sub 13), branch: master, commit date: 2020-04-08 21:23, hash: blender/blender@1239cab11f
Worked: (newest version of Blender that worked as expected)

Short description of error
When exporting a mesh with vertex colors as glb with draco compression enabled. The exported vertex color is different from what it should be. I haven't been able to import the exported glb into blender to check if this is a bug with blender or if it's an issue with three.js. But my exported mesh fails to render correctly both in https:*threejs.org/editor/ as well as on https:*gltf-viewer.donmccurdy.com/ and on https://sandbox.babylonjs.com/

Exact steps for others to reproduce the error

Create a simple mesh with vertex colors (see attached blend file)
Export as glb
Export again as glb but with draco mesh compression enabled
Notice how vertexColorTest.glb works fine on the websites mentioned above, but how vertexColorTestCompressed.glb doesn't.

Additional info
https://gltf.insimo.com/ has an implementation of draco mesh compression with working vertex colors. Notice how 'vertexColorTest insimo.glb' works on all sites mentioned above.

vertexColorTest insimo.glb

vertexColorTest.blend

vertexColorTest.glb

vertexColorTestCompressed.glb

**System Information** Operating system: Darwin-19.4.0-x86_64-i386-64bit 64 Bits Graphics card: AMD Radeon Pro 460 OpenGL Engine ATI Technologies Inc. 4.1 ATI-3.8.24 **Blender Version** Broken: version: 2.83 (sub 13), branch: master, commit date: 2020-04-08 21:23, hash: `blender/blender@1239cab11f` Worked: (newest version of Blender that worked as expected) **Short description of error** When exporting a mesh with vertex colors as glb with draco compression enabled. The exported vertex color is different from what it should be. I haven't been able to import the exported glb into blender to check if this is a bug with blender or if it's an issue with three.js. But my exported mesh fails to render correctly both in https:*threejs.org/editor/ as well as on https:*gltf-viewer.donmccurdy.com/ and on https://sandbox.babylonjs.com/ **Exact steps for others to reproduce the error** - Create a simple mesh with vertex colors (see attached blend file) - Export as glb - Export again as glb but with draco mesh compression enabled - Notice how vertexColorTest.glb works fine on the websites mentioned above, but how vertexColorTestCompressed.glb doesn't. **Additional info** https://gltf.insimo.com/ has an implementation of draco mesh compression with working vertex colors. Notice how 'vertexColorTest insimo.glb' works on all sites mentioned above. [vertexColorTest insimo.glb](https://archive.blender.org/developer/F8459626/vertexColorTest_insimo.glb) [vertexColorTest.blend](https://archive.blender.org/developer/F8459629/vertexColorTest.blend) [vertexColorTest.glb](https://archive.blender.org/developer/F8459628/vertexColorTest.glb) [vertexColorTestCompressed.glb](https://archive.blender.org/developer/F8459627/vertexColorTestCompressed.glb)

Jesper van den Ende commented

2020-04-09 14:06:34 +02:00

Added subscriber: @jespertheend

Germano Cavalcante commented

2020-04-10 14:54:36 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2020-04-10 14:54:36 +02:00

Inport/Export glTF Addon has its own channel for bug reports:
https://github.com/KhronosGroup/glTF-Blender-IO/issues/

You can be more successful there.

Inport/Export glTF Addon has its own channel for bug reports: https://github.com/KhronosGroup/glTF-Blender-IO/issues/ You can be more successful there.

Jesper van den Ende commented

2020-04-10 16:21:27 +02:00

Thanks for the heads up!
I created an issue over there https://github.com/KhronosGroup/glTF-Blender-IO/issues/1019

Thanks for the heads up! I created an issue over there https://github.com/KhronosGroup/glTF-Blender-IO/issues/1019

Julien Duroure commented

2021-01-04 21:00:18 +01:00

Added subscriber: @JulienDuroure