summary if no one wants to do it
- Lumen is not ray tracing, it's using another form of tracing
- lumen also has specular reflections
- large objects are traced through voxels
- medium objects are signed distance fields
- small objects are screen space (similar to Gears 5 on Seriex X)
- you can see screen space artifacts in the demo
- uses temporal accumulation like RT, so there's a latency to lighting
- micro-polygon rendering is primarily used in offline rendering like film
- nanite uses a high resolution tiling normal map for fine details to help conserve vram through virtual texturing
- nanite scales the model complexity by how many pixels it takes up
- micro sized objects are shadowed with SS shadows and combined with a virtualized shadow map
- shadow map resolution is aligned with screen resolution
- shadows are filtered to create a penumbra
- unknown if nanite applies to animated objects like foliage or hair, or characters
- demo is dynamic res (mostly 1440p) at 30fps
- resolution scaling is more expensive with this technique
- pixel-sized triangles is pretty inefficient so how is Epic avoiding wasteful rendering?