Lightmap baking: Cast shadows set to OFF, but still casting shadow (Progressive lightmaps)

When I bake lightmap, objects that have cast shadows set to off still cast shadows. Is there any way to fix that? It's annoying bug and it has been there since 2018.x version.

 

Is that a bug? I think you need to uncheck the "static" to stop it from casting shadows in lightmaps.

 

Are you sure it's from direct light? That's what the off in cast shadows prevents.

Indirect shadows are not quite shadows. If you want it to not contribute to GI at all, you either need to not have it static, or maybe try something, switching to something transparent for the bake, then switch to the normal shader after.

 

Is there a way to have something receive indirect baked GI, but not contribute shadows to other objects?

We're using 2022 and have decal quads that unless we set entirely to real-time lighting leave shadow blotches on the mesh they float just overtop of. (Almost like AO is bleeding)

 

If by "not contribute shadows" you mean direct shadows, then yes (by turning off cast shadows).

If you mean "shadows" by bounced indirect light / skylight etc, then not really.

My workaround is to duplicate the immediate environment, set baked scaled for the environment to 0 (so I don't waste lightmap space on those), then place the item that I want to receive GI but not affect the environment in the duplicate environment (then place it in its proper place at runtime).

So for example, I have a few items I want to be placed on this desk later in the game.


I bake them here:



Then I bring them to the actual play area at runtime.

 

Pretty much, my desire is for the decals to have the same baked lighting as the mesh they're placed upon, but not affect said meshes own baked lighting. (As if the decal was a perfectly transparent vinyl sticker.)

Runtime relocation works for some areas, but is problematic in others where there isn't the space for duplicate scene geometry.

Ultimately, I've discussed this topic before, but the general consensus was it's not really supported and was hpoing you had an amazing workaround I could steal.

The part I don't get is that it's not affecting all decal meshes equally despite identical settings. Decals use their own Lightmap Parameter's assets based on the suggestions in the linked thread, but it's had limited success.

 

Any update on this? Been searching high and low. Surely there must be a way to let an object receive lightmaps without casting AO (or affecting light otherwise). How do one deal with skirt meshes and decals for instance without it? This is puzzling

Edit: I found a workaround

1. Change material to transparency and set alpha to 0
2. Bake your lightmaps
3. Set your material back to original settings