Maxime Heckel published a detailed guide on Aug 6 2024 that shows how to create a custom post‑processing effect in React Three Fiber, starting with a RetroEffect class that extends Effect from the postprocessing package and exposing a GLSL fragment shader for dithering — the article can be read in full here.
Wiring the effect into a Three.js scene
The demo sets up a standard R3F canvas, adds an EffectComposer, and wraps the custom class with wrapEffect so it can be used as a JSX component. The shader receives the rendered frame via inputBuffer and computes per‑pixel luminance before applying a chosen dithering algorithm. The code is a minimal, copy‑and‑pasteable starting point for any R3F project.
Dithering methods covered
- White‑noise dithering – compares pixel luminance to a random value generated in GLSL, producing a binary black‑or‑white output.
- Ordered Bayer‑matrix dithering – uses a 4×4 (or larger) matrix to produce repeatable patterns; the matrix is normalized by dividing by 16.
- Blue‑noise dithering – samples a pre‑generated noise texture (128 px square) to get a smoother, less repetitive threshold.
- Color quantization – maps each channel to the nearest of n discrete levels using
floor(color * (n‑1) + 0.5) / (n‑1), allowing 2‑color, 4‑color, or custom palettes via a lookup texture.
Integration trade‑offs
The guide is free and the code is open‑source, so there is no monetary cost. However, the techniques rely on custom GLSL and the @react-three/postprocessing stack, meaning you must be comfortable editing shaders and managing extra render passes. The article does not provide performance measurements, so the added shader pass could increase frame time on low‑end devices—test on your target hardware before shipping.
When to try it
If your product UI already uses WebGL or three‑js visualisations and you want a nostalgic visual style without pulling in a heavyweight library, the guide offers a ready‑made recipe. Keep an eye on updates to the postprocessing library and community examples to gauge stability before committing to production code.
