GPU profiling - Shadow Projection on Static lights?

Hello fellas,

I’ve been learning UE4 for a few weeks now, only possible with the great ressources on the learning platform and the forums… but I need some extra help now.

I can’t figure out why the Shadow Projection is so expensive if everything on my scene is on static. Even why there is any resource dedicated to Shadow Depths. I thought that Shadow Projection and Shadow Depths are required for non-baked lighting, but every single light in the scene is on Static, and I re-built the lighting. I thought I should have 0 resources dedicated to lighting/shadows at run-time if everything is on Static… Did I get it wrong?

There are about 30 lights that cause this. Actually it’s a BP actor replicated 30 times. But why is it spending at all if the lighting is baked?? Every issue comes from this BP, so maybe I set-up something wrong? Or it got bugged because of so many tests I did?

Please help me figure this out…


i don’t get why ShadowDepths generates this cubemap…


https://forums.unrealengine.com/core/image/gif;base64

The BP that spends most resources… replicated 30 times.

https://forums.unrealengine.com/core/image/gif;base64

It is definitely creating shadowmaps for the point lights. Are you sure that nothing is moving and the light build is up-to-date?

Anyway, regardless of the issue, it seems to me that you need a spot light here, more than a point light.

I’m using an IES profile, so I thought that it doesn’t matter if spot or point… anyway I just changed it and will re-bake (I did several builts before posting. So I’m sure everything is on Static, but also I’m probably missing something)

Are you sure you don’t have any other light? Like a directional or a skylight casting shadows… what is the output of stat LightRendering?

Yes, there is a Directional Light and a Sky in the scene, and 4 spots on top of those 30… all set to static. I think something weird was happening here.

Anyway, after changing from point(IES) to spots(IES) fixed the thing, now performance seems more like I thought it would be:


So now I’ll improve the look and add more meshes… but I was stuck on the performance. I have no idea if it was the point lights with IES, or because changing/testing so many times maybe got something bugged… I also did try raytracing this morning, and then switched back. Maybe this unbugged something also?

but anyway, thank you @Ale_32 your comment pointed me in the right direction.