Intel HD Graphics issues with post processing

[teub]

Describe the bug

While trying to run an OpenGL filament app on a laptop, I noticed I couldn't get the postprocess to work without MSAA 2x (pixels are rendered black in 1x).

By using the released samples, I could reproduce an issue that is probably related: disabling bloom breaks the rendering unless I enable the MSAA4X checkbox.

To Reproduce Steps to reproduce the behavior:

• On a HD Graphics 520 gpu, run "material_sandbox -a opengl cube.obj"
• uncheck the "bloom" checkbox, notice the cube disappears
• check the MSAA4x checkbox, notice the cube reappears

The cube.obj file comes from https://github.com/google/filament/blob/main/assets/models/cube/cube.obj

Screenshots

https://user-images.githubusercontent.com/11277063/211883185-dd4ae530-f049-4c31-93ce-4c7fa941db6f.mp4

Desktop (please complete the following information):

• OS: Windows 10
• GPU: Intel(R) HD Graphics 520
• Backend: OpenGL

[pixelflinger]

What if you use ssao or fxaa instead of mssa? Does it make it work too?

[teub]

FXAA is already checked by default and unchecking it doesn't make the cube appear. Enabling SSAO doesn't fix it either. On the other hand, TAA does.

[Alan-FGR]

I'm having the same problem: I'm trying to render with no MSAA or other post-processing/AA, but that yields a fully black render, whereas even with 2x MSAA it renders correctly. I'm currently on an integrated Intel Iris.