Journal

animated explainers · rendering · sampling

Journal

Rendering, explained visually

Short animated explainers on the math behind real-time and offline graphics. Every video comes with its measurements underneath.

6:01 The Penumbra Condition — Radiance Cascades in Flatland Why a shadow is crisp at the washer drum and blurry down the aisle, and the global-illumination trick built on that. 5:43 The Half-Vector Jacobian — Visible Normals of Isotropic GGX Why sunset glare on a wet road is so hard to render cleanly, and the trick that fixes it. 5:29 The Toksvig Factor: Specular Exponent from Normal Length Why distant metal in games fizzes and sparkles as you move, and how to calm it. 5:08 Shadow Map Bias as Geometric Error Why game shadows come out striped or float off people's feet, and the one setting behind both. 4:38 Multiple Importance Sampling and the Balance Heuristic Those stray white dots in a noisy render are called fireflies, and one simple blend makes them go away. 3:41 Light Sampling and the Area Jacobian Aim your rays at a lamp and forget one small factor, and the whole room comes out at the wrong brightness. 4:11 Solid Angle and the Rendering Equation Why a skylight overhead lights a room far more than the same window low on the wall. 4:49 Importance Sampling: Phong Lobe vs Cosine Two ways to aim the same rays: one leaves bright speckles, the other leaves dark holes. 4:06 Reprojection and Depth Discontinuities Why a character moving in front of a wall can leave a smeared trail behind them in games. 4:19 Temporal Accumulate vs TAA Ghosting The ghostly trails behind moving objects in modern games, and the trick that erases them. 4:12 Tone Mapping: Scene-Referred to Display-Referred Why the sun in a photo blows out to flat white, and how renderers squeeze real brightness onto a screen. 4:56 Split-Sum Image-Based Lighting How games make shiny objects reflect a whole room without tracing a single ray. 4:19 Parallax Occlusion Mapping: Height March, Flat Silhouette Game bricks that look deep head-on turn out to be painted flat once you see them edge-on. 3:54 Anisotropic Footprints: Jacobian, Ellipse, Over-Blur Why floor textures in games turn to mush when you look along them, and how to keep them sharp. 4:15 How a mipmap presents in the scene Distant brick walls in games blur on purpose, because the alternative is a crawling, shimmering mess.