# Water surface

an animated Gerstner sea refracting the scene below it.

```{raw} html
<a class="example-run-button" href="../demos/features_3d_water.html">▶ Run in browser</a>

```

**Tags:** `3d` `water` `gerstner` `refraction` `transparent`

A WaterSurface3D is a built-in transparent pass (its own shader pair, design
D16), NOT a ShaderMaterial. Its vertex stage tessellates a grid and displaces it
by a sum of four Gerstner waves whose direction + strength come from the
WorldEnvironment wind and whose phase comes from the frame clock. Its fragment
stage refracts the submerged geometry (sampling the scene colour/depth copy that
the surface's presence switches on), fades from a shallow tint to a deep tint
with water depth, mixes a Fresnel reflection, and foams where the water meets the
shore. Submerged pillars and a sloped floor show the depth fade, refraction
wobble and shore foam; the wind drives the swell.


Usage:
    uv run python examples/features/3d/water.py

## Source

```{literalinclude} ../../examples/features/3d/water.py
:language: python
:linenos:
```