Slower realtime shadow update speed? Possible?

Questions & Answers
1

Hello, so I am making a scene with multiple realtime lights and shadows but if there are too many lights the scene obviously becomes too laggy. So what I’d like to know is if it’s possible to calculate some shadows slower i.e. instead of calculating the shadow every frame it calculates shadows once every second. The idea behind it is that if it calculates shadows once every second it wouldn’t be as performance heavy, so less laggy. Also baking the shadows is not an option as I need to turn lights on and off.

So is it possible, would it improve performance and how would one do it?

2

No, it’s not. The reason being that the shadows are rendered in frame-space, not world-space. So, that means that if your camera frame updated, it would use the shadowing from the previous frame where the camera may have been looking a completely different direction. Since the shadows use a depth buffer, that data would be incoherent unless you were using a static scene and camera.