Movable Light & Global Illumination issue

Hello !

For a school project, I made the interior of a building with some window. At the start of the level, all the window are covered by security iron panel. So their is no light from the exterior coming where the player is.
During the playtime, the player can Activate a button, so the security iron panel open up slowly, letting the light enter in the room.

So I placed a Light-Source, working like the sun. put it Movable so the shadow are in real-time. But the parts of the room that are in the shadow are too dark. But when i’m using a SkySphere, it’s precalculated so the room is no longer in the dark when the Iron panels are down…

How can I light my scene with a “Global illumination” when the Iron panel are Up, but still have a very dark room when the Iron panel are down ? It’s a VR experience, it is possible without burning the Host PC ?

Thank you very much for your help :slight_smile: