Lighting

• 4096 lights (upstream 64): camera-following light grid with resampled importance sampling.
• Emissive surfaces as lights (rendering/pathtracing/emissive_lights).
• Light visibility memory (rendering/pathtracing/light_visibility_memory): hidden lights stop taking samples.
• Radiance cache (rendering/pathtracing/radiance_cache): bounces end on cached light.
• Transmission bounces (rendering/pathtracing/transmission_bounces): glass, ice and water get their own bounce budget; matches 6 bounces in about 70% of the time, so icicles under an eave no longer go dark at the default 3.
• Light reuse (rendering/pathtracing/light_reuse, off by default): ReSTIR DI reuses light samples across pixels and frames.
• Indirect light reuse (rendering/pathtracing/indirect_reuse, off by default): ReSTIR GI; rooms and shade lit by bounced light are far less noisy at the same samples.
• Shadow-only casters bounce light.
• Lit raster transparents and rain (rendering/pathtracing/max_transparency_layers 0), still traced in reflections.

Images#

Indirect light reuse: the same 4 samples per pixel, off then on; both brightened 3x to show the noise.