Bloom broken on Linux studio

[lukedodd]

Bloom seems to be broken on Linux studio.

Studio version 0.8.3 but latest studio versions crash on startup on Ubuntu 22.04.

To Reproduce

Open up any scene in studio, switch to forward AAA pipeline. Crank up bloom settings. Observe a vertical banding effect. Shown here on cornel-box/main_direct.scn from sample projects.

Expected behavior

Smooth bloom without vertical banding.

Desktop:

• OS: Ubuntu 22.04. nvidia gpu (3080).

[astrofra]

Hi,
thanks for this report.
Looks like a precision issue. I will try to reproduce it on my own system and will let you know.

[astrofra]

Hi,
the issue with the Bloom is not specifically related to Linux ... but to OpenGL.
There is something in the GL coordinates system that we probably don't handle properly.
We will keep you posted as soon as this is fixed.

[lukedodd]

Thanks @astrofra!

[lukedodd]

@astrofra Changing computeTexel to return just the uv argument instead of the current logic in the bloom upsample and down-sample shaders fixes the issue but has issues at the edge of the screen.

[astrofra]

@lukedodd Thanks Luke!
I tried this (and a couple of other things) for an early diagnosis but, oddly, I don't observe the same result on Windows/OpenGL.
This issue is now on our "immediate" list :)