Gradients

A gradient in this catalog is a pure WGSL function that maps a scalar t (typically in [0, 1]) to an RGB triple. They include perceptually uniform scientific colormaps (Viridis, Magma, Inferno, Plasma, Cividis, Turbo), classic ramps (Jet, Spectral, Grayscale), and parameterised families like Cubehelix and the Inigo Quilez cosine palette.

Pull one into a composition by slug, then call it from your fragment stage with whatever drives t in your scene — UV.x for a horizontal ramp, length(uv - 0.5) for radial, atan2 for conic, or any custom field:

let main = r#"
@fragment fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
    return vec4<f32>(viridis(in.uv.x), 1.0);
}
"#;
let shader = Shader::new(&["gradient/viridis", main])?;

Each preview below renders the colormap directly to a 256×256 frame using a UV-derived t chosen to show the palette’s character.

cividis

Matplotlib’s Cividis fit — perceptually uniform and color-vision-deficient friendly. Driven horizontally across the frame.

fn cividis(t: f32) -> vec3<f32>

cubehelix

Dave Green’s cubehelix ramp: gentle rotating hue with linear lightness. Preview uses defaults start=0.5, rot=-1.5, hue=1.0, gamma=1.0.

fn cubehelix(t: f32, start: f32, rot: f32, hue: f32, gamma: f32) -> vec3<f32>

grayscale

Linear gray ramp from black to white.

fn grayscale(t: f32) -> vec3<f32>

inferno

Matplotlib’s Inferno colormap — a perceptually uniform black-purple-red-yellow ramp. Driven horizontally across the frame.

fn inferno(t: f32) -> vec3<f32>

jet

Classic MATLAB Jet (not perceptually uniform; prefer Turbo for new visualisations). Swept radially in the preview to highlight all bands.

fn jet(t: f32) -> vec3<f32>

magma

Matplotlib’s Magma colormap — a perceptually uniform black-purple-pink-cream ramp. Driven horizontally across the frame.

fn magma(t: f32) -> vec3<f32>

palette_iq

Inigo Quilez cosine palette: a + b * cos(2π * (c*t + d)). The four vec3<f32> parameters control offset, amplitude, frequency, and phase. Preview uses (0.5, 0.5, 0.5), (0.5, 0.5, 0.5), (1, 1, 1), (0, 0.33, 0.67) swept around the frame as a conic gradient.

fn palette_iq(t: f32, a: vec3<f32>, b: vec3<f32>, c: vec3<f32>, d: vec3<f32>) -> vec3<f32>

plasma

Matplotlib’s Plasma colormap — a perceptually uniform purple-pink-yellow ramp. Driven horizontally across the frame.

fn plasma(t: f32) -> vec3<f32>

spectral

ColorBrewer-style spectral rainbow (not perceptually uniform). Useful as a quick diverging or qualitative palette. Swept radially in the preview.

fn spectral(t: f32) -> vec3<f32>

turbo

Polynomial fit to Google’s Turbo colormap — a perceptually balanced rainbow that replaces Jet for most use cases. Driven horizontally across the frame.

fn turbo(t: f32) -> vec3<f32>

viridis

Matplotlib’s Viridis approximated via the IQ cosine palette — the default perceptually uniform colormap for scientific visualisation. Driven horizontally across the frame.

fn viridis(t: f32) -> vec3<f32>