'Mixed lights': Using adaptive probes without lightmapes (realtime or baked)

So adaptive light probes seem great, but they strike me as having one caveat: they require mixed lighting to be enabled via ‘Baked Global Illumination’ which seems to always trigger the baking of lightmaps?.. I don’t want to use lightmaps, my assets are already using additional UV channels in their custom shaders, and lightmap UVs mess with that.

Now the good news is, you can actually bake lights without lightmaps. Just set those lights to ‘mixed’ or 'baked. The bad news is, ordinarily Unity won’t let you unless you enable 'Baked Global Illumination`.


Another snippet of good news is that setting the inspector to ‘Debug’ mode does lets you.

Adaptive lightprobes + Baked Global Illumination:

Adaptive probes without Baked Global Illumination:

Adaptive probes without Baked Global Illumination, but lights set to ‘mixed’ via inspector in debug mode:

The one thing missing in the last method is the inclusion of the skybox. I’ve added a ‘baked’ directional casting a blue light down with a 90 degree shadow angle to add back some sky light

But as is visible from the Light inspector screenshot, my lights are now littered with warnings about using ‘wrong’ light mode settings (even though clearly to provide good results). It claims settings are overridden (which they aren’t actually; my light set to ‘baked’ is not casting any realtime light whatsoever)

So, the question is: Is there a way to use ’ Baked Global Illumination’ without it baking lightmaps of any sorts? Because I’m not finding it…

Otherwise, would there be a ‘clean’ way to have lights behave as mixed or baked? (That is, without unity giving all these warnings?)

Mixed lighting mode just controls whether direct contribution and shadows from lights should be baked or not, it doesn’t determine whether or not lightmaps are baked in the first place.

Now the good news is, you can actually bake lights without lightmaps. Just set those lights to ‘mixed’ or 'baked. The bad news is, ordinarily Unity won’t let you unless you enable 'Baked Global Illumination`.

This isn’t generally true. I think the behavior you are seeing is coincidental. The lightmapper is filtering out the lights, as they are treated as realtime (like the warning says), but APV is not doing that same filtering, even though it technically should.

If you don’t want any lightmaps to be baked, just open the inspector for each GI contributor/static object and set the Receive Global Illumination setting to “Light Probes”. If no scene objects have the setting set to “Lightmaps”, no lightmaps will be baked. This is the intended workflow.

That being said - should we have a separate global toggle for lightmaps and APV? Probably. I’ll take a note

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I see, so rather than setting lights to ‘baked’ or ‘mixed’ leaving ‘Mixed Lighting’ disabled, the intended workflow is to actually enable ‘Mixed Lighting’ and instead set all meshes to use probes only? (In fact, if I understand correctly, you’re saying that me being able to bake lights to light probes the way I’m doing it is actually a bug)

I’ve never paid much attention to these mesh settings as I’ve never worked with light probes before, but I’m seeing the setting… Unfortunately, mass-selecting objects in a large scene to change this setting is a bit fickle… even one non-static object in there will have the dropout greyed out:

I’m still in pre-production, so I could simply go the way you described once I’ll start building content. For now I’ll just keep tricking the APV into baking those lights while having Mixed Lighting disabled :wink:

And yeah, some sort of global toggle to use APV without lightmaps would be pretty convenient for those who rather not deal with lightmaps :+1:

Your understanding is correct. I’ve added an internal ticket for improving multi-editing of mesh renderers and for a global APV/Lightmap toggle