Export / Import .obj file with Principled Transmission parameter does not work #86736

New Issue

Sebastian Feistl · 2021-03-19T12:16:17+01:00

Sebastian Feistl commented

2021-03-19 12:16:17 +01:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce RTX 3070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 461.09

Blender Version
Broken: version: 2.91.0, branch: master, commit date: 2020-11-25 08:34, hash: blender/blender@0f45cab862
Worked: (newest version of Blender that worked as expected)
Also tested with Blender 2.91.2 and 2.83.12

Addon Information
Name: Wavefront OBJ format (3, 8, 1)
Author: Campbell Barton, Bastien Montagne

Short description of error
Exporting an .obj file with a Principled material that has a Transmission value set is not working as expected. Re-importing the object will automatically set the Transmission parameter back to 0.

According to the documentation Importing & Exporting shader nodes should support the Transmission parameter of the Principled node.
However, the Transmission parameter value does not seem to be included in the export or Blender fails to import the property.

Exact steps for others to reproduce the error

create an object with a Principled shader node
set the Transmission parameter to anything else than 0.
Export the model as .obj and re-import it in a fresh Blender file.

Expected result: The Transmission value is the same as defined before the export.
Actual result: The Transmission value is 0.

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: GeForce RTX 3070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 461.09 **Blender Version** Broken: version: 2.91.0, branch: master, commit date: 2020-11-25 08:34, hash: `blender/blender@0f45cab862` Worked: (newest version of Blender that worked as expected) Also tested with Blender 2.91.2 and 2.83.12 **Addon Information** Name: Wavefront OBJ format (3, 8, 1) Author: Campbell Barton, Bastien Montagne **Short description of error** Exporting an .obj file with a Principled material that has a Transmission value set is not working as expected. Re-importing the object will automatically set the Transmission parameter back to 0. According to the documentation [Importing & Exporting shader nodes ](https://docs.blender.org/manual/en/latest/addons/import_export/node_shaders_info.html) should support the Transmission parameter of the Principled node. However, the Transmission parameter value does not seem to be included in the export or Blender fails to import the property. **Exact steps for others to reproduce the error** - create an object with a Principled shader node - set the Transmission parameter to anything else than 0. - Export the model as .obj and re-import it in a fresh Blender file. **Expected result**: The Transmission value is the same as defined before the export. **Actual result**: The Transmission value is 0.

Sebastian Feistl commented

2021-03-19 12:16:17 +01:00

Added subscriber: @sebastianfeistl