Vulkan: Broken colors when baking LightmapGI

[RedMser]

Godot version

4.0.dev (ce6f284)

System information

Windows 10 64-bit, Vulkan Clustered, NVIDIA RTX 2080, Driver version 497.09

Issue description

I was trying to debug another issue related to lightmap baking. I created a simple MRP which creates a very broken bake texture:

Steps to reproduce

• Create a simple .blend file for the scene - mark it for lightmap bake
• Add directional light node to be baked
• Create LightmapGI, set camera attributes, reduce quality to Low
• Bake and look at the results

Minimal reproduction project

lightmap_corruption.zip

[RedMser]

On the official alpha 16 build, I only manage to get a black bake result

The bake works as expected in alpha 11. I don't have other alpha versions available to test, but I'll take a shot into the dark and say it's due to #63751

[Calinou]

I can confirm this on 4.0.alpha ce6f284 (Linux, NVIDIA 515.65.01).

I get a different result though:

Setting LightmapGI's environment mode to Scene gives me this:

@RedMser Which graphics card model and driver version are you using?

[RedMser]

Updated the original post with specs. Since 516.94 is latest, I'll need to check after an update, but since you seem to have issues as well it might be unrelated.

[clayjohn]

The bake works as expected in alpha 11. I don't have other alpha versions available to test, but I'll take a shot into the dark and say it's due to #63751

You have good intuition. I just tried building immediately before and after #63751 and can confirm that it introduced the issue. Fix coming in shortly.