Lighting help

Hello,

I’m still fairly new to the Unreal Engine but the problem I am having is where I have one room where there is no sunlight casting into it (Pic 1) but eventually parts of the roof will open which will cast in the sunlight (Pic 2) but the light doesn’t bounce around the room and fill it compared to one of the other rooms I have done (Pic 3). I know this can be resolved by building the lighting while the roof is open but in doing that when the roof is closed for the first part of my animation there is a lot of light when there shouldn’t be. So I was wondering if there is a way to have the light calculate the bounces instantly as the roof opens or if you can switch between two different light builds at all?

Hopefully I have explained this well, any help would be greatly appreciated.

Cheers!

PIC #1
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PIC #2
eaed529a578827028108c97e2e446e820e84e9f7.jpeg

PIC #3
1e4423586a568059e32687159455f766a76f0a9e.jpeg

Check to see if your directional light is static or movable. I believe that movable lights are not built to bounce light. Make sure it is a static light and perhaps put the Indirect Lighting up to 3 or so and see what you can do from there.

Depending on what you are trying to accomplish you can use Lightmass GI to help bounce more light around, but that could be a bit intensive on hardware so check the FPS.

Dynamic GI via Distance Fields can also help bounce light around more or Light Propagation Value (LPV). These can get intensive, so just use it to help a bit but do not go overboard.