threejs-temporal-surfaces

name	threejs-temporal-surfaces
description	Build view-aligned and screen-space surface effects in Three.js. Use for touch-history frost and thaw, ping-pong accumulation, reduced-resolution blur, crystalline masks, two-scale refraction, and procedural rain droplets that refract and blur a background through wet glass.

Temporal Surfaces

Choose persistent history or procedural screen-space evolution explicitly. Do not fake accumulation with time-only noise, and do not allocate history for an effect whose complete state is analytic in time.

This skill contains exemplary examples and assets beyond descriptive guidance, they're worth studying, referencing, or even copying. Use them sufficiently when relevant and do NOT blindly skip them.

Pipeline

persistent surface: input -> ping-pong state -> blur -> structure -> refraction
procedural surface: time/coverage -> analytic field -> optical normal -> refraction/blur

Read references/ping-pong-accumulation.md for an exact frost pass graph, pointer-history channels, blur and refraction coupling, and implementation defects that must be corrected.

Read the touch-history frost implementation for the previous/deposit/next state transition, reduced blur, static structures, frost-mask composition, and two-scale refraction.

Read references/refractive-window-rain.md and the refractive window rain implementation for layered static and travelling droplets, finite-difference optical normals, background refraction, stochastic disc blur, aspect fill, and presentation.