Lighting a Procedurally-Generated Indoor Scene

Ommi

First of all -- hello good people!

This may slide more into "discussion", I'm not sure. But if I'm not looking for a specific answer, as such, I'm certainly seeking particular advice.

I am creating levels through code, and am really struggling with making the lighting look at all attractive. They are indoor, so directional lighting seems inappropriate. As such, I'm using spotlights if they make sense with the model, and omnilights otherwise. For the latter, I'm using a fairly large range, and a small attenuation. This fills the room, but it feels... out of proportion. Yet if I reduce the range, areas plunge into dark shadow that also look, well, kinda yucky.

I feel one would normally using indirect lighting here, but it is my understanding that any sort of baked lighting is unavailable to me, since there is no time during design to do the baking.

That said, I am building the level out of segment scenes created in the editor. Intersections, hallway bits, portions of rooms. BUT, after all the segments are placed, there is a decoration pass where additional goodies are added, removed, or otherwise fondled, in an effort to break up the repetition. So while I can create some baked lighting in a given segment, I (presume!) it could not in any way consider adjoining segments, or changed geometry during decoration.

Which brings me here. Have I misunderstood how baked lighting works? Is it even a solution to my "make it look nicer" problem? Should I be considering something else entirely?

How should I approach this?

Megalomaniak

@Ommi said:

That said, I am building the level out of segment scenes created in the editor. Intersections, hallway bits, portions of rooms. BUT, after all the segments are placed, there is a decoration pass where additional goodies are added, removed, or otherwise fondled, in an effort to break up the repetition. So while I can create some baked lighting in a given segment, I (presume!) it could not in any way consider adjoining segments, or changed geometry during decoration.

Sounds very similar to warframe, may be worth checking out perhaps? I'm pretty sure they do use quite a bit of baked lighting.

cybereality

You can see if ambient light helps. With the spot/omni lights and some ambient it should look okay. You can also try baking indirect light for each piece in its own scene. You can't bake direct light, and the indirect light may look incorrect at the seams or at some angles, but may still be better than nothing. You can also try real-time global illumination. I never got it to look as good as baked lighting but it should definitely help.

Calinou

You can bake GIProbe/VoxelGI at run-time by calling the bake() function on it (make sure all your static MeshInstances have Use In Baked Light enabled). However, you can't bake BakedLightmap at run-time.

cybereality

That's good to know @Calinou

Ommi

Thank you all so much, I will spend the evening working with the GIProbe and see where it takes me. The docs are silent on VoxelGI, so I'm guessing that is a 4.0 thing and not concern myself with it too much at the moment.

The "takes five to twenty seconds" comment does give me pause -- if I try to multithread the bake() function, is it going to all end in tears?

@cybereality -- The (admittedly quick) search I did on the real-time Global Illumination you mentioned suggests it is also a 4.0 feature. Please yelp if I'm confused.

On that note though, if the consensus is that my time would be better spent putting the problem aside for the moment, and returning to it with 4.0, so be it. It isn't as if I don't have an awful lot to do and learn.

Calinou

Thank you all so much, I will spend the evening working with the GIProbe and see where it takes me. The docs are silent on VoxelGI, so I'm guessing that is a 4.0 thing and not concern myself with it too much at the moment.

VoxelGI is the new name of GIProbe in Godot 4.0. It uses an entirely different implementation, but the principle is the same.

The "takes five to twenty seconds" comment does give me pause -- if I try to multithread the bake() function, is it going to all end in tears?

I presume baking will always happen on the main thread since OpenGL is not thread-safe. While Vulkan can be thread-safe, I think baking will still happen on the main thread in Godot 4.0.

Feel free to give threads a try, but it's not guaranteed to work out well here.

cybereality

@Ommi said: @cybereality -- The (admittedly quick) search I did on the real-time Global Illumination you mentioned suggests it is also a 4.0 feature. Please yelp if I'm confused.

I believe it is called GIProbe in Godot 3.x.