Black Hole shader preview: A black hole bending light around it, its glowing disc lensed over the top of its shadow.
ittybitty

Black Hole

A black hole bending light around it, its glowing disc lensed over the top of its shadow.

Code

The usage always matches the preview, layers and performance settings included. No build step or package.

Copy embed gives one block to paste into any page or site builder, no setup. For your own code: add black-hole.js, ittybitty-shader.js, runtime.js, pointer.js, texture.js next to this page. Highlighted values follow the controls.

<!-- Quickest: one element. Size it with CSS; it fills its box. -->
<script type="module" src="./ittybitty-shader.js"></script>
<ittybitty-shader effect="black-hole" style="width: 100%; aspect-ratio: 16 / 10;"></ittybitty-shader>

<!-- Or with JavaScript, for full control: -->
<canvas id="black-hole" aria-hidden="true" style="width: 100%; aspect-ratio: 16 / 10; display: block"></canvas>

<script type="module">
  import { blackHole } from './black-hole.js';

  const canvas = document.getElementById('black-hole');
  const effect = blackHole(canvas, {
    showSky: true,
    showDisc: true,
    showHole: true,
    speed: 0.4,
    tilt: 0.12,
    size: 1,
    disc: 1,
    doppler: 0.6,
    stars: 0.6,
    quality: 0.5,
    background: 'stars',
    image: '',
    interactive: true,
    responsiveness: 0.4,
    hot: '#fff1d6',
    cool: '#ff7a2e',
    // Performance
    dpr: 1,
    adaptive: true,
  });

  // Later: effect.set(…), effect.pause(), effect.resume(), effect.destroy()
</script>

Details

Each ray of light is traced as gravity bends it, which is what makes the famous image: the far side of the accretion disc is lifted up and over the shadow, a thin photon ring hugs its edge, and the side spinning towards you burns brighter. Stars, or your image, are pulled into an Einstein ring behind it. The pointer orbits the view. Heavy by design; adaptive resolution is on.

Payload
8.0 KB brotli for black-hole.js and ittybitty-shader.js and runtime.js and pointer.js and texture.js, measured at build time. See the method.
Resolution
Device pixel ratio capped at 2.
Frame rate
Display rate.
When unseen
Stops rendering when the canvas leaves the viewport or the tab is hidden, and resumes where it left off.
Reduced motion
Shows a single still frame. Controls still update it.
Layers
Up to five effects fuse into one shader and one draw call. Filters such as dithering and halftone process the layers beneath them.
Browsers
Any browser with WebGL2: Chrome and Edge 56+, Firefox 51+, Safari 15+.
Licence
MIT. Copy it, change it, ship it.