Pixi.js powers Retina's cinematic effects layer: smart-zoom interpolation, cursor smoothing, frame styling, background gradients. WebGL-accelerated 2D rendering with a mature filter system. Three.js was overkill for 2D-only work; p5.js wasn't built for production performance. Pixi hit the sweet spot — GPU-fast, filter-rich, predictable frame budget.
p5.js
Three.js