Release Notes: Off-Main-Thread Rendering

2026-09-30

Highlights

Rendering now runs in a Web Worker. All five render modes (ASCII, dither, halftone, voxel, lines) and the full effects pipeline draw on an OffscreenCanvas owned by a worker, so the UI (sliders, buttons, panels) no longer competes with the render loop.
Same renderers, same settings. Existing renderers were adapted rather than rewritten. Rendering logic, settings, and the registry are unchanged.
Added: footer in the settings panel.

Footer in the settings panel.
src/worker/render.worker.ts: owns the canvas and runs the render pipeline.
src/worker/renderWorkerController.ts: the only main-thread object that talks to the worker (canvas transfer, frame back-pressure, settings sync, capture and text-export requests, stats).
src/worker/protocol.ts: typed messages shared by both sides.

Viewport no longer runs useFrameLoop. It creates the canvas and worker on mount, then a small frame pump hands camera frames to the worker. useFrameLoop is no longer used by Viewport.
The canvas is created inside an effect instead of JSX. A canvas can only be transferred to a worker once, so this keeps React StrictMode's double mount from throwing InvalidStateError.
Canvas resizing goes through the worker. The main thread can no longer set width/height on the transferred canvas.
Performance stats (fps, render time) are posted by the worker every ~20 frames instead of being sampled with Math.random().