ehm, how is that supposed to help? he said he has some skylight intensity and everything is too bright inside. your suggestion would make exactly that: too bright inside. or if he lowers the skylight to be less dark inside, he’ll get very dark shadows outside.
@marasovec unfortunately there’s no way to filter out areas or use negative lights to darken the ambient light produced by a movable skylight.
you can use a static or stationary skylight instead, and precompute the lighting for it. this way the ambient light will be local per area. you can still have a movable sun light if you need dynamic time of day. if your skylight is stationary you can animate the skylight color with your time of day.
yes, this means using lightmass and baking lighting. however if you force every actor’s mesh in your scene to use the Volumetric Lightmap, you don’t need to create lightmap UVs at all.
if you need an immediate solution personally this would be my preferred method. as long as you don’t need to spawn static geometry at game time (i.e. having procedural levels) I find this to be a very good compromise between quality (much better than a movable skylight) and iteration time (you bake lighting yes, but no need to worry about lightmap UVs)
if you really need a movable skylight it’s often suggested a ‘solution’ with some sort of custom volume, sort of like a tunnel, which modifies the skylight intensity as you pass through it. this way when you enter the cave it gets darker as you pass the entrance, and find it to be dark when you’re finally inside. I find this solution to be very lacking because if you go inside and get darker skylight and look outside it will be very dark. and if you go outside and look inside it will be very bright. so you need to come up with more and more trickery to avoid this effect (like putting a dark semi-transparent plane to darken the inside, using postprocess volumes, etc)
you can also try using Distance Field AO. it works well up to a certain size, but once your interiors are big enough the occlusion becomes too “local”, and the floor/walls/ceiling are too far apart to occlude eachother and you’re back to having the unwanted outdoors-like ambient light inside.
there’s also the option of using a very dim skylight (tuned for interiors) and couple it with LPV. the idea is to tune the LPV values to be strong enough for the GI to act as ambient light. I’ve seen it work well enough, it’s just limited by the LPV featureset (very coarse voxels causing bleeding on thin walls, limited GI distance with a hard cut, performance not as good)
another option is to use raytracing in your skylight, but this limits your game to users with RTX cards.
you can also wait for UE5 to come out next year and use the Lumen lighting system, it should allow to do exactly what you need.
another trick to block the light from a Movable Skylight: make a decal, make a decal material for it, set the Decal Blend Mode to Ambient Occclusion, set the material AO output to 0, fill your interiors with these decals, profit.
probably drawcall heavy and requires a lot of placement. but you can effectively block all dynamic skylight with it. the decals can fade out by distance so you can fine tune your performance vs distance tradeoff, and since it’s material-based you can do gradients for transitions.
another solution is to use my Localized IBL system (link in my sig). but you need to modify the engine for that.