Local Sky

The colour of the sky at a given hour, from real single scattering.

isomer.sh/effects/localsky

Knobs

Continue on iPhone
Preset
18.6
0.30
2.20
0.26
Colour2
1.00
0.30
Light3
0.00
4.00
1.20
Shape1
0.64
Motion1
0.00
Still frame

What reduced motion shows: 2 s.

Install

Code

components/isomer/localsky.tsx
'use client';
// Generated by isomer. Do not edit by hand; run `isomer add` again to update. (from packages/react/src/Localsky.tsx)
// generated by packages/react/scripts/gen-components.mjs, do not edit
import type { CSSProperties } from 'react';
import { useIsomerCanvas, type Mount } from './useIsomerCanvas';
// @ts-ignore: the runtime is plain JS with no type declarations
import * as runtime from './localsky.js';

const { DEFAULTS, mount } = runtime as { DEFAULTS: LocalskyKnobs; mount: Mount };

export interface LocalskyKnobs {
  hour: number;
  haze: number;
  sunSize: number;
  horizonHeight: number;
  exposure: number;
  drift: number;
  afterglow: number;
  groundLight: number;
  discBrightness: number;
  glareStrength: number;
  sunX: number;
}

export interface LocalskyProps extends Partial<LocalskyKnobs> {
  className?: string;
  style?: CSSProperties;
  /** Render this one frame (seconds) and run no clock. Used by the parity tests. */
  time?: number;
  paused?: boolean;
  /** Draw t = 0 once while drift is 0, and when the user prefers reduced motion. Default true. */
  respectReducedMotion?: boolean;
  /** Keep each frame readable after it is shown, for canvas.toDataURL or readPixels. Read at mount. Default false. */
  preserveDrawingBuffer?: boolean;
}

export const localskyDefaults: Readonly<LocalskyKnobs> = DEFAULTS;

export function Localsky({ className, style, time, paused, respectReducedMotion, preserveDrawingBuffer, ...props }: LocalskyProps) {
  const knobs = { ...DEFAULTS };
  for (const k of Object.keys(DEFAULTS) as (keyof LocalskyKnobs)[]) {
    const v = props[k];
    if (v !== undefined) (knobs as Record<string, unknown>)[k] = v;
  }
  const ref = useIsomerCanvas({ mount, knobs, time, paused, respectReducedMotion, preserveDrawingBuffer, clock: knobs.drift !== 0 });
  return <canvas ref={ref} className={className} style={{ display: 'block', width: '100%', height: '100%', ...style }} />;
}

Parity

iPhone 17 Pro simulator, iOS 26.3.1 against Chromium headless + SwiftShader, 15 October 2026.