YouTube’s member ‘KurtLoeffler’ has presented a video, showcasing his voxel cone tracing plugin for the Unity engine. According to KurtLoeffler, this technique approximates global illumination by maintaining a voxelized representation of the world in camera centered cascades (only 1 cascade shown here), and tracing cones through the volume based on surface normal and position to see what lighting is visible from that point.
Moreover, this technique supports standard lights which get injected into the volume similar to shadow mapping, and also supports light emitting emissive geometry based on surface shader emission value. Light emitting geometry takes no extra processing. This demo is only using 1 cascade but ideally 3 cascades will be used which will allow correct indirect lighting in any size environment.
As KurtLoeffler added:
“I also plan to have cheap lights which contribute to GI without the overhead of rendering the scene from the lights point of view. The only limitation of these is that the GI contribution wouldnt respect shadow casting objects. These types of lights should be extremely cheap if they have a small to medium radius.”
KurtLoeffler admitted that this technique is quite ‘expensive’ and does require DX11 in order to run. The demo was running on an Nvidia GTX660 at 50-60fps with with 6 additional image effects applied.
Voxel Cone Tracing Unity Plugin Preview