I would like to use the light of my environment to influence my actors, similar to the way that the bugs avoid the flashlight in the UE5 release demo.
I suspect that the demo solved this using some cone proxy and I’m looking for a more general solution. F.ex. have bats fly out of a room if it gets to bright, or have an NPC avoid dark spaces.
Is there some way to access the various caches created by Lumen? Such as the Surface Cache? or the Voxel Lighting (from Global Distance Field) mentioned in the stream cast on lumen?
You could potentially do raycasts into the lumen scene to gather radiance, but I could see that getting very technical very quickly. In terms of user-exposed ways of accessing the data? I don’t know, but It seems possible if expensive. I’m curious how much of that logic would be part of the lumen pipeline, and how much would need to be hand-authored.
Also, the voxel lighting system is no longer used for distant lighting to my knowledge. The global distance field now does reversed lookups into the surface cache (I have not looked into how), but it’s significantly less leaky than the voxel representation.