GIProbe indirect lighting on GridMaps not working

[DevMagicLord]

Godot 3.0.2 Win 7 64 bits GeForce 960

Hi there,

I made a scene with an emissive material and Global Illumination, but lighting only throw on floor, but walls don't receive any bounces lighting.

https://github.com/DevMagicLord/Godot3/blob/master/bugs/Giprobeissue.jpg

While materials without normal map and roughness map receives all indirect lighting.

https://github.com/DevMagicLord/Godot3/blob/master/bugs/giprobeissue2.jpg

Materials with normal map and roughness, metallic maps, needs to receive lighting bounces.

[Calinou]

Does your scene use procedural meshes such as CubeMesh inside a MeshInstance? From my testing, GIProbe bakes won't affect them.

[DevMagicLord]

No, it's imported cubes as .obj files, they are used in a Meshlib for 3D Gridmaps. This means Gridmaps are not good for GiProbe ?

[groud]

Probably related to #18056

[DevMagicLord]

I found GiProbe baking works well on standard objects, and emissive objects must also have the flag "used in baked lighting" to true.

But imported 3D tiles with "used in baked lighting" to true and saved as meshlib, baking the Giprobe doesn't bake well on Gridmaps, it's very dark.

On center this is gridmap while others are objects. https://github.com/DevMagicLord/Godot3/blob/master/bugs/giprobeGridmapsbaking.jpg?raw=true

The issue is about gridmaps.

[EzraT]

This happens to me too with Godot 3.0.6 on Linux. There is a very clear difference to how GIProbe looks on regular MeshInstance nodes, compared to how it looks on a Gridmap.

[reduz]

Sorry, without a test scene, figuring out what is going on is impossible. Closing.

[EzraT]

@reduz Reproduction Project Details: https://github.com/godotengine/godot/issues/18056#issuecomment-439538543

[EzraT]

Could this one be added to the 3.1 milestone?

[reduz]

Actually, it seems to be working, but the emission channel is not strong enough. Lights can compensate this because they have a bake energy value but materials don't. I promise to add this after 3.1 is out, as I will be doing some rewriting to the GIProbe code.

[KoBeWi]

Still valid in 3.2.4 beta3 Can't test on master, because GridMap doesn't work (incompatible meshlib?)

[SoloCodeNet]

Gi PRobe not working on voxel based model, no texture on the mesh just magica voxel import tested with meshinstance directly work fine, add gridmap with same model (left and right) and re-bake capture : https://ibb.co/pJ8D9Z8

[Calinou]

This appears to be fixed in master according to my tests in https://github.com/godotengine/godot/issues/56030.

[EzraT]

Issue still present in 3.5.beta3.

[EzraT]

I did some more testing, and I found something that could hopefully shed some more light on this problem.

To clarify again, this is what the scene in the MRP looks like when using just meshinstances for the hallways:

Now here's what the same meshes look like in a gridmap, using the exact same settings in the GIProbe:

The GIProbe Energy is turned to 16 in both scenes to demonstrate the problem better.

What I discovered is this: When I turn down the Bias property on the GIProbe node to zero in the scene with only MeshInstances, things start to look very similar to the GridMap scene:

Changing the Bias value in the Gridmap scene also does not result in any different visuals.

Could it be that GIProbe is not correctly applying the Bias value to gridmaps?

[Calinou]

@ezrat Thanks for checking this issue :slightly_smiling_face:

Can you reproduce this with a MultiMeshInstance? GridMap uses MultiMesh behind the scenes for rendering.

[EzraT]

@Calinou Check #45313 As far as I'm aware MultiMeshInstances in Godot 3 do not affect GIProbe, as the issue says. Happy to help!