The Reflection Buffer — every write-up

202610

2026 · APR · 18Light Bounces OnceReal-Time LightScreen-space directional occlusion: sampling the 3D hemisphere so occlusion keeps its direction and color, then re-using the blocked samples as secondary emitters for one bounce of indirect light.
2026 · APR · 14The Room ItselfA Path TracerScaling to San Miguel and the Bistro: importance-sampled HDR environment lighting, an area light aggregated from every emissive triangle, a binary scene cache, and offline denoising.
2026 · APR · 04Where Corners Stay DarkReal-Time LightAlchemy screen-space ambient occlusion: spiral-sampling each pixel's G-buffer neighborhood for the obscurance IBL flattens out, then a depth- and normal-aware bilateral blur before it multiplies the ambient term.
2026 · MAR · 29Through GlassA Path TracerA transmission lobe added to the BRDF: Snell refraction at every microfacet, total internal reflection, Beer's-law tint, and the power-heuristic MIS that quiets the sharper lobe.
2026 · MAR · 28Light, Pre-FilteredReal-Time LightImage-based lighting in real time: the HDR sky pre-filtered to nine spherical-harmonic coefficients for diffuse, importance-sampled with GGX and Hammersley for specular, then tone-mapped back to display range.
2026 · MAR · 14MirrorsA Path TracerThe Cook–Torrance microfacet BRDF (Phong NDF, Smith masking, Schlick Fresnel), and the multiple importance sampling that kills the fireflies it introduces.
2026 · MAR · 01From the Light's Point of ViewReal-Time LightShadow mapping by rendering depth from the light's view, then four progressively softer ways to read it back: biased binary, PCF, variance, and moment shadow maps, blurred in compute.
2026 · MAR · 01Light Finds Its WayA Path TracerMonte Carlo path tracing: cosine-weighted BRDF sampling, Russian roulette, and the shadow rays that reach a clean image in a tenth the passes.
2026 · FEB · 09The G-BufferReal-Time LightDeferred shading: geometry and material baked into a four-target G-buffer so one Cook–Torrance BRDF evaluation runs per visible pixel, additive per light no matter how many.
2026 · FEB · 04First HitA Path TracerA CPU ray caster: sphere, box, cylinder, triangle, and the BVH that drops a single frame from 89 seconds to 130 milliseconds.