Cycles Regression: Not all information from "Multiscatter GGX" in the "Glass BSDF" is saved to render passes #91893

New Issue

Alaska · 2021-10-02T04:03:52+02:00

Alaska commented

2021-10-02 04:03:52 +02:00

System Information
Operating system: Linux-5.14.0-1-amd64-x86_64-with-glibc2.32 64 Bits
Graphics card: NVIDIA GeForce RTX 3090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 470.63.01

Blender Version
Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-10-01 21:26, hash: 12e8c78353
Worked: Prior to Cycles-X merge

Short description of error
When rendering with a material that makes use of a Glass BSDF with the Distribution Method set to Multiscatter GGX, then not all information from the object with that shader will be saved to passes.

This can be observed by rendering an object with the material Glass BSDF then comparing the result from the final render to the result generated by combining all the render passes using this method shown in the Blender manual: https://docs.blender.org/manual/en/latest/render/layers/passes.html#id3


Result from Render	Result from Compositor

Exact steps for others to reproduce the error

Create a scene in Cycles and create an object.
Give the object a Glass BSDF material and change the distribution method to Multiscatter GGX.
Enable all the render passes required for the compositor setup shown in the picture above.
Setup the compositor with that node setup.
Render the scene and compare how the scene looks when directly rendered by Cycles compared to when you combine the passes together with the compositor. Notice that they're different.
Re-run this test in a version of Blender prior to the Cycles-X merge and observer this issue doesn't happen.

Or, download this file and do steps 5 and 6 from above.
Missing render pass data - Cycles.blend

**System Information** Operating system: Linux-5.14.0-1-amd64-x86_64-with-glibc2.32 64 Bits Graphics card: NVIDIA GeForce RTX 3090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 470.63.01 **Blender Version** Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-10-01 21:26, hash: `12e8c78353` Worked: Prior to Cycles-X merge **Short description of error** When rendering with a material that makes use of a `Glass BSDF` with the `Distribution Method` set to `Multiscatter GGX`, then not all information from the object with that shader will be saved to passes. This can be observed by rendering an object with the material `Glass BSDF` then comparing the result from the final render to the result generated by combining all the render passes using this method shown in the Blender manual: https://docs.blender.org/manual/en/latest/render/layers/passes.html#id3 ![Render Layers Compositing.png](https://archive.blender.org/developer/F10726857/Render_Layers_Compositing.png) |![Final Render Output.jpg](https://archive.blender.org/developer/F10726871/Final_Render_Output.jpg)|![Compositor Output.jpg](https://archive.blender.org/developer/F10726874/Compositor_Output.jpg)| | -- | -- | |Result from Render|Result from Compositor| **Exact steps for others to reproduce the error** 1. Create a scene in Cycles and create an object. 2. Give the object a `Glass BSDF` material and change the distribution method to `Multiscatter GGX`. 3. Enable all the render passes required for the compositor setup shown in the picture above. 4. Setup the compositor with that node setup. 5. Render the scene and compare how the scene looks when directly rendered by Cycles compared to when you combine the passes together with the compositor. Notice that they're different. 6. Re-run this test in a version of Blender prior to the Cycles-X merge and observer this issue doesn't happen. Or, download this file and do steps 5 and 6 from above. [Missing render pass data - Cycles.blend](https://archive.blender.org/developer/F10726904/Missing_render_pass_data_-_Cycles.blend)

Alaska commented

2021-10-02 04:03:52 +02:00

Added subscriber: @Alaska