Operating system: Linux-5.4.0-45-generic-x86_64-with-debian-bullseye-sid 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 450.51.06
Broken: version: 2.91.0 Alpha, branch: master, commit date: 2020-09-01 12:39, hash: rB526fbdec3b6a
Also broken in the 2.90 and 2.83.5 LTS!
Short description of error
The Alpha channel display in the Image Editor gets completely garbled if you switch it to show only the Alpha channel, change the current frame by pressing cursor left or right and the pressing F12 again. This is what the Alpha should look like:
And here's how it looks after changing the frame:
Exact steps for others to reproduce the error
- Open the attached blend file (basically an empty scene with the default cube):
- Press F12 to render and to open the Image Editor. Everything looks fine.
- Switch the Image Editor to show the Alpha channel:
- Press cursor right or left to change the current frame
- Press F12 again
- The Alpha is a total mess
This happens in 2.83.x, 2.90 and the latest master. Both in CPU and GPU mode.
When saving the garbled image from the Image Editor (to a PNG e.g.) the Alpha is fine. So it looks to me like it's only a display problem?