Three.js Shaders
Quick Start
javascript
import * as THREE from "three";
const material = new THREE.ShaderMaterial({
uniforms: {
time: { value: 0 },
color: { value: new THREE.Color(0xff0000) },
},
vertexShader: `
void main() {
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`,
fragmentShader: `
uniform vec3 color;
void main() {
gl_FragColor = vec4(color, 1.0);
}
`,
});
// Update in animation loop
material.uniforms.time.value = clock.getElapsedTime();
ShaderMaterial vs RawShaderMaterial
ShaderMaterial
Three.js provides built-in uniforms and attributes.
javascript
const material = new THREE.ShaderMaterial({
vertexShader: `
// Built-in uniforms available:
// uniform mat4 modelMatrix;
// uniform mat4 modelViewMatrix;
// uniform mat4 projectionMatrix;
// uniform mat4 viewMatrix;
// uniform mat3 normalMatrix;
// uniform vec3 cameraPosition;
// Built-in attributes available:
// attribute vec3 position;
// attribute vec3 normal;
// attribute vec2 uv;
void main() {
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`,
fragmentShader: `
void main() {
gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}
`,
});
RawShaderMaterial
Full control - you define everything.
javascript
const material = new THREE.RawShaderMaterial({
uniforms: {
projectionMatrix: { value: camera.projectionMatrix },
modelViewMatrix: { value: new THREE.Matrix4() },
},
vertexShader: `
precision highp float;
attribute vec3 position;
uniform mat4 projectionMatrix;
uniform mat4 modelViewMatrix;
void main() {
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`,
fragmentShader: `
precision highp float;
void main() {
gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}
`,
});
Uniforms
Uniform Types
javascript
const material = new THREE.ShaderMaterial({
uniforms: {
// Numbers
floatValue: { value: 1.5 },
intValue: { value: 1 },
// Vectors
vec2Value: { value: new THREE.Vector2(1, 2) },
vec3Value: { value: new THREE.Vector3(1, 2, 3) },
vec4Value: { value: new THREE.Vector4(1, 2, 3, 4) },
// Colors (converted to vec3)
colorValue: { value: new THREE.Color(0xff0000) },
// Matrices
mat3Value: { value: new THREE.Matrix3() },
mat4Value: { value: new THREE.Matrix4() },
// Textures
textureValue: { value: texture },
cubeTextureValue: { value: cubeTexture },
// Arrays
floatArray: { value: [1.0, 2.0, 3.0] },
vec3Array: {
value: [new THREE.Vector3(1, 0, 0), new THREE.Vector3(0, 1, 0)],
},
},
});
GLSL Declarations
glsl
// In shader uniform float floatValue; uniform int intValue; uniform vec2 vec2Value; uniform vec3 vec3Value; uniform vec3 colorValue; // Color becomes vec3 uniform vec4 vec4Value; uniform mat3 mat3Value; uniform mat4 mat4Value; uniform sampler2D textureValue; uniform samplerCube cubeTextureValue; uniform float floatArray[3]; uniform vec3 vec3Array[2];
Updating Uniforms
javascript
// Direct assignment material.uniforms.time.value = clock.getElapsedTime(); // Vector/Color updates material.uniforms.position.value.set(x, y, z); material.uniforms.color.value.setHSL(hue, 1, 0.5); // Matrix updates material.uniforms.matrix.value.copy(mesh.matrixWorld);
Varyings
Pass data from vertex to fragment shader.
javascript
const material = new THREE.ShaderMaterial({
vertexShader: `
varying vec2 vUv;
varying vec3 vNormal;
varying vec3 vPosition;
void main() {
vUv = uv;
vNormal = normalize(normalMatrix * normal);
vPosition = (modelViewMatrix * vec4(position, 1.0)).xyz;
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`,
fragmentShader: `
varying vec2 vUv;
varying vec3 vNormal;
varying vec3 vPosition;
void main() {
// Use interpolated values
gl_FragColor = vec4(vNormal * 0.5 + 0.5, 1.0);
}
`,
});
Common Shader Patterns
Texture Sampling
javascript
const material = new THREE.ShaderMaterial({
uniforms: {
map: { value: texture },
},
vertexShader: `
varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`,
fragmentShader: `
uniform sampler2D map;
varying vec2 vUv;
void main() {
vec4 texColor = texture2D(map, vUv);
gl_FragColor = texColor;
}
`,
});
Vertex Displacement
javascript
const material = new THREE.ShaderMaterial({
uniforms: {
time: { value: 0 },
amplitude: { value: 0.5 },
},
vertexShader: `
uniform float time;
uniform float amplitude;
void main() {
vec3 pos = position;
// Wave displacement
pos.z += sin(pos.x * 5.0 + time) * amplitude;
pos.z += sin(pos.y * 5.0 + time) * amplitude;
gl_Position = projectionMatrix * modelViewMatrix * vec4(pos, 1.0);
}
`,
fragmentShader: `
void main() {
gl_FragColor = vec4(0.5, 0.8, 1.0, 1.0);
}
`,
});
Fresnel Effect
javascript
const material = new THREE.ShaderMaterial({
vertexShader: `
varying vec3 vNormal;
varying vec3 vWorldPosition;
void main() {
vNormal = normalize(normalMatrix * normal);
vWorldPosition = (modelMatrix * vec4(position, 1.0)).xyz;
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`,
fragmentShader: `
varying vec3 vNormal;
varying vec3 vWorldPosition;
void main() {
// cameraPosition is auto-provided by ShaderMaterial
vec3 viewDirection = normalize(cameraPosition - vWorldPosition);
float fresnel = pow(1.0 - dot(viewDirection, vNormal), 3.0);
vec3 baseColor = vec3(0.0, 0.0, 0.5);
vec3 fresnelColor = vec3(0.5, 0.8, 1.0);
gl_FragColor = vec4(mix(baseColor, fresnelColor, fresnel), 1.0);
}
`,
});
Noise-Based Effects
glsl
// Simple noise function
float random(vec2 st) {
return fract(sin(dot(st.xy, vec2(12.9898, 78.233))) * 43758.5453);
}
// Value noise
float noise(vec2 st) {
vec2 i = floor(st);
vec2 f = fract(st);
float a = random(i);
float b = random(i + vec2(1.0, 0.0));
float c = random(i + vec2(0.0, 1.0));
float d = random(i + vec2(1.0, 1.0));
vec2 u = f * f * (3.0 - 2.0 * f);
return mix(a, b, u.x) + (c - a) * u.y * (1.0 - u.x) + (d - b) * u.x * u.y;
}
// Usage
float n = noise(vUv * 10.0 + time);
Gradient
glsl
// Linear gradient vec3 color = mix(colorA, colorB, vUv.y); // Radial gradient float dist = distance(vUv, vec2(0.5)); vec3 color = mix(centerColor, edgeColor, dist * 2.0); // Smooth gradient with custom curve float t = smoothstep(0.0, 1.0, vUv.y); vec3 color = mix(colorA, colorB, t);
Rim Lighting
javascript
const material = new THREE.ShaderMaterial({
vertexShader: `
varying vec3 vNormal;
varying vec3 vViewPosition;
void main() {
vNormal = normalize(normalMatrix * normal);
vec4 mvPosition = modelViewMatrix * vec4(position, 1.0);
vViewPosition = mvPosition.xyz;
gl_Position = projectionMatrix * mvPosition;
}
`,
fragmentShader: `
varying vec3 vNormal;
varying vec3 vViewPosition;
void main() {
vec3 viewDir = normalize(-vViewPosition);
float rim = 1.0 - max(0.0, dot(viewDir, vNormal));
rim = pow(rim, 4.0);
vec3 baseColor = vec3(0.2, 0.2, 0.8);
vec3 rimColor = vec3(1.0, 0.5, 0.0);
gl_FragColor = vec4(baseColor + rimColor * rim, 1.0);
}
`,
});
Dissolve Effect
glsl
uniform float progress;
uniform sampler2D noiseMap;
void main() {
float noise = texture2D(noiseMap, vUv).r;
if (noise < progress) {
discard;
}
// Edge glow
float edge = smoothstep(progress, progress + 0.1, noise);
vec3 edgeColor = vec3(1.0, 0.5, 0.0);
vec3 baseColor = vec3(0.5);
gl_FragColor = vec4(mix(edgeColor, baseColor, edge), 1.0);
}
Further reference
See references/shaders-reference.md for extending built-in materials, GLSL built-in functions, common material properties, shader includes, instanced shaders, debugging, performance tips, and see also.