As pointed out here only movable objects and lights can make use of the new lighting channel feature.
However I found a simple workaround in a limited experiment:
Have two static meshes
Have two static lights which reach both meshes. Make them of different color
Set one mesh to movable. Change it’s lighting channel from 0 to 1. Set it back to static
Select one light, set it to movable, change it’s lighting channel from 0 to 1. Set it back to static
Now build the light.
As a result, the two meshes will receive light from their respective light source each.
Since I am working on a major lighting problem in my level and this would be the solution for me, I want to ask if this is a legitimate usage of the feature or is it possible that this will not work in the future because it might be changed to the original behavior where only movable objects can have channels?
I think I mentioned a similar trick in my page for setting these lighting channels for static objects, but the lights will still only use movable lights for the lighting channels. Static Lighting is not supported for baked lighting.
In your setup it seems like you have the two lights and are only setting one to static to bake and the other is left to static. The movable light isn’t baking anything with lightmass so I suppose it can be considered a workaround for your situation, but it’s not really baking lights for both, only the one.
Here is an example using your same setup with baked and without baked for both while having the same lighting channel set up that you outlined.
Channel 0 for the lights and the ceilings, walls, and floor
Lights on the Right:
Channel 1 for the two walls and the lights
In the image on the left the static lighting for the ones on the left and the wall on the right is using movable lights. All walls here are set to static mobility. You can see that the baked lighting still affects the one on the right because baked lighting will not respect lighting channels. However, if you set the wall to movable and then change the Indirect Lighting Quality to ILCQ Off the moveable walls will no longer take any contribution from the baked lighting since the movable walls use the indirect lighting cache to make them blend better for the environment. Disabling this makes it only use the direct lighting from the movable lights with the correct lighting channels.
That’s probably a lot of information and it’s may not necessarily make a lot of sense since it’s out of the intended use for lighting channels. There are certainly other ways to go about forcing baked lighting information to respect the assets, but that is definitely outside of the realm of intended workflow and practice as well and requires a very specific setup and lots of patience to pull off.
Ok, you’re right, one was set to stationary and here I thought I found a solution
My problem is that I need multiple streaming levels in my game, some of which represent a daytime environment and others a night time setup, so people can step out of a city that has night into a wilderness where the sun shines.
I have read others posts with the same problem, so maybe this should be considered for future enhancements, something like an external static light information that can be exchanged at runtime
