Dark cave in open world level

I have an open world level which is lit by a skysphere and a skylight - is it possible to make a cave where the light doesnt affect it ? Atm my cave is way to light - how would you go around making something like this ? Do i need to make it as a seperate level ? Or is there a way to somehow exclude the skylight from the cave area ?

You could probably have some kind of trigger that would disable the skylight when you walk into the cave. The problem would then become adding in ambient lighting. You’d likely need to place many small radius point lights, with shadows disabled, to fake the ambiance and add some life back into the cave.

You might be able to do something with sub levels, where the sub level has baked lighting, but I’ve never played around with mixing the two like that and don’t even know if it’s possible or not. I’ll try rigging up a test scene to see if I can make something work.

In short, no it’s not possible. What you want is to have some sort of “winding path” into your cave that will fade the skylight out as you go down into it (winding so you don’t see the outside darkening). It’s all about using tricks to achieve the effect and mask the transition.

Now this VERY heavily depends on what kind of cave you’re talking about and what kind of entrance it has, etc etc… But after playing around with it all for a little bit, I have definitely managed to transition from a fully dynamically lit outdoor scene, to a fully statically lit indoor scene, using level streaming. I had a persistent level with ONLY the player start in it. Within the persistent level, I had it load the outdoor sub level on begin play. Your outdoor level will contain your dynamic lighting. Your indoor level will contain the interior of the cave and it’s static lighting(make sure to set a lightmass volume around the cave inside the indoor sub level). I used a blueprint interface, with a boolean in it, to relay messages between levels for turning the skylight influence off.

post processing volume probably the most simple solution followed by DamirH’s solution.

There are a lot of different ways to pull it off, but it heavily depends on the scene. The big problem with only doing it in post or only dimming the skylight is that you will have no indirect lighting in there at all. That’s why I initially suggested using a ton of tiny radius point lights, to fake in some bounce lighting. You can definitely get even better results by baking out a sub level for it that has static lighting. Obviously, you don’t want to bake out lightmaps for some huge 4km^2 map, so that’s why I suggested doing it with sub levels.

Is there any good tutorials on how to setup a simple sub level like this ? Unreals own tutorial is 1 hour long as go through some pretty advanced stuff it seems - unlike what we need.

can’t remember the exact stream, but epic did a demo on how they do caves, they built the level normally, then had localized pp volumes fade in as the player walked towards them, a one sided fog sheet to darken the inside when viewed from outside. iv done it before and it works pretty well.

I found the sheet - the fog sheet at the entrance was a neat tip - however it doesnt solve how to make the inside of the cave dark. I even tried to change my skysphere and light source to static and bake out the lighting - its still hella bright inside my cave :-/

if you’ve resorted to static lighting it shouldn’t be an issue anymore. perhaps auto-exposure is “making it bright” ? otherwise it’s hard to know without looking at it

This is two pictures - one is outside the cave and one is inside the cave

Ill try and bake the lighting once again - what settings should i use ? Should i use station or static for my directional light ? And is there any other settings i should turn off/on to get a proper bake ? This is my first time in unreal so im kinda new to this

The main lights should be stationary. Lights at do not need to cast dynamic shadows for characters can be static. You can only have 3 stationary lights that overlap, so adjust the size of the lights if needed.