Godot version

4.0.dev (2a9dd65)

System information

Fedora 34, GeForce GTX 1080 (NVIDIA 470.74)

Issue description

If a DirectionalLight3D with shadows enabled is visible, LightmapGI won't be sampled during rendering. This means the scene will not receive lighting from the lightmap (but it will still ignore environment lighting).

Vulkan Clustered backend

Vulkan Mobile backend

Edit: I've found that this is linked to directional light shadows.

DirectionalLight3D hidden

DirectionalLight3D without shadows visible

DirectionalLight3D with shadows visible

Steps to reproduce

• Import a glTF scene. Set the light bake mode to Static Lightmaps in the Import dock and click Reimport.
• Add a LightmapGI node.
• Bake lightmaps.
• Switch to Vulkan Mobile backend in the project settings (search for back end).
  • Note: The MRP linked below already uses the Vulkan Mobile backend by default.
• Restart the editor. Notice lightmaps no longer contribute to the static objects' lighting.

Minimal reproduction project

test_vulkan_clustered_vs_mobile.zip