Stationary lights more expensive than movable

Development Rendering
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1

Hi
We have been working with a game the past 1½ year and have during that time discovered that our stationary light sources are much more expensive to use than movable lights.

Is this because we have too many objects casting shadows, close to the stationary lights? As we understand, the stationary lights produces two shadow types for each object - is this why its expensive? Or is it the size of the baked lighting maps?

for example we have 10 stationary light sources (not overlapping more than allowed) in one of our levels. If we make these movable, we gain around 25 FPS and +10ms. very strange.

Does anyone knows what is going on?
Thanks

2

I’ve had the same thing on occasion, I think its to do with the amount of memory used by the static shadows forcing the GPU to work from a smaller area.

Have you tried reducing the lightmap res on things setting the lights to static and using ‘Dynamic shadow distance stationary lights’?

Can really make a huge difference. Set it initially to about 1200. You can then have pretty low res static shadows, because they are always in the distance.

3

if your game is open world or a huge map i guess stationary lights are not a good option.