Ray traced lightmap shadows

In case you read the README and was surprised by this, it's not full path tracing in the style of https://github.com/sultim-t/vkquake-rt. There are several limitations with this approach, but it's much faster than vkquake-rt could ever hope to be. You can actually use this at native 4K (or even more with SSAA) when targeting high framerates :slightly_smiling_face:

Only dynamic lights are affected, as the direction of static lightmaps isn't known by the engine.
Shadow resolution is limited by lightmap resolution, which means shadows are relatively blurry. The upside is that it looks quite natural in action and less distracting with moving objects.

Screenshots/videos for those interested: