# Liquid glass caustics: parameters and references

Source: https://meniscus.site/effects/caustics · Updated 2026-09-27

**Looks like:** Bright, wavy, focused light lines and cells — the network of light at the bottom of a pool or cast by a glass on a table.

Also called: water light, pool light, light network, voronoi light, caustic.

**Use in:** Backgrounds and hero scenes (water, wellness, weather, AI ambience), light cast by a large glass object onto the surface below. Use sparingly and dimly behind chrome.

**Avoid:** Bright caustics directly behind text-bearing glass (kills legibility); fast animation; caustics as a UI fill.

**Parameters:** cell scale 3–7 cells per 300 px, intensity 20–40 % additive, two layers at different scales/speeds, animation 0.2–0.6 units/s.

**Design tool:** Use a caustic texture (photo or generated Voronoi-edge pattern) in Screen/Add at 20–40 %, slightly blurred, tinted to the light colour.

**Web:** WebGL/canvas background (see caustics() in the web recipe); CSS fallback: a looping caustic texture video or image with mix-blend-mode: screen.

**Shader:** `Worley cell borders: pow(1 - smoothstep(0, 0.3, F2 - F1), 3), multiply two animated layers, add to the backdrop.`

## References

![A frosted rounded pane over an animated caustic light network on deep teal.](https://meniscus.site/gallery/caustics-dark-studio.webp)

## Use it with your assistant

This spec is what the Meniscus MCP server's `get_effect_spec` tool returns for `caustics`. Materials, colours, light and composition rules that apply to every effect are in the [liquid glass guide](https://meniscus.site/liquid-glass). Connect: `claude mcp add --transport http meniscus https://meniscus.site/mcp` — setup for every client: https://meniscus.site/docs