What is the best way to reduce the performance cost of volumetric shadows?




I’m making an indie game. In order to be universal, I need to manage rendering costs on low-spec devices.
My graphic concept is light and dark. I’m inspired by Dune, and the best way to represent this is with Volumetric Fog and Volumetric Shadow. You can see in the image how I’m trying to achieve this. However, Volumetric Shadow is so computationally intensive that it easily drops frames. I try to reduce this as much as possible with Stationary, but the light is too broad, and I always end up with an X. (I’m not using Lumen).
Here’s what I tried to do to reduce the GPU computation.

  • Reducing the number of voxels per unit area
  • Turning off squared distance falloff
  • Reducing the maximum draw distance

But despite the above efforts, I haven’t seen much of an improvement. How can I drastically reduce it? Is there any way to bake the rendered result into a translucent Mesh, or do I need to lay it out one by one with translucent materials?

Id look into how to bake lighting, don’t know how to off the top of my head as I’m relatively new to the engine and haven’t found a need for it yet, but I’m sure you can

Volumetrics are rarely ever used on low spec devices, the effect is faked with geometry

there are multipe ways to convey dirt in the air. fog particle billboards or for godrays you can create trapezoid prism shapes or cone shapes and texture them with additive or modulate materials. light and dark. there are some cheats to get the soft edges. like vertex colored support edges or fresnel blended edges. you could also add local post postprocessing volumes to convey a lift or darkening inside of those “zones”. volume shadow maps can be baked too. that’s the low end tech.