cesiumjs-materials-shaders

CesiumJS Materials, Shaders & Post-Processing

Version baseline: CesiumJS 1.139 (March 2026). All imports use ES module style.

Material System (Fabric JSON)

Material defines surface appearance for Primitives through a JSON schema called Fabric. Materials compile to GLSL and are consumed by MaterialAppearance or PolylineMaterialAppearance.

Built-in Material Types

Surface: Color (color), Image (image, repeat), DiffuseMap, AlphaMap, SpecularMap, EmissionMap (image, channel(s), repeat), BumpMap, NormalMap (image, channel(s), strength, repeat).

Patterns: Grid (color, cellAlpha, lineCount, lineThickness), Stripe (evenColor, oddColor, repeat), Checkerboard (lightColor, darkColor, repeat), Dot (lightColor, darkColor, repeat).

Effects: Water (baseWaterColor, normalMap, frequency, animationSpeed), RimLighting (color, rimColor, width), Fade (fadeInColor, fadeOutColor, maximumDistance).

Terrain: ElevationContour (color, spacing, width), ElevationRamp (image, minimumHeight, maximumHeight).

Polyline: PolylineArrow (color), PolylineDash (color, gapColor, dashLength, dashPattern), PolylineGlow (color, glowPower, taperPower), PolylineOutline (color, outlineColor, outlineWidth).

Creating Materials

import { Material, Color, Cartesian2 } from "cesium";

// Shorthand with fromType (preferred for built-in types)
const colorMat = Material.fromType("Color", { color: new Color(1.0, 0.0, 0.0, 0.5) });

// Full Fabric notation
const gridMat = new Material({
  fabric: {
    type: "Grid",
    uniforms: { color: Color.GREEN, cellAlpha: 0.1, lineCount: new Cartesian2(8, 8) },
  },
});

// Async loading -- awaits textures before first frame, no flicker
const imageMat = await Material.fromTypeAsync("Image", { image: "./textures/facade.png" });

Custom Fabric with GLSL Source

Use source for inline GLSL. Uniforms declared in uniforms are available by name in the shader.

import { Material, Color } from "cesium";

const pulseMaterial = new Material({
  fabric: {
    uniforms: { color: Color.CYAN, speed: 2.0 },
    source: `czm_material czm_getMaterial(czm_materialInput materialInput) {
      czm_material material = czm_getDefaultMaterial(materialInput);
      float pulse = sin(czm_frameNumber * speed * 0.01) * 0.5 + 0.5;
      material.diffuse = color.rgb;
      material.alpha = color.a * pulse;
      return material;
    }`,
  },
  translucent: true,
});

Applying Materials to Primitives

import { Primitive, GeometryInstance, RectangleGeometry, Rectangle,
  MaterialAppearance, Material, Color, Cartesian2 } from "cesium";

viewer.scene.primitives.add(new Primitive({
  geometryInstances: new GeometryInstance({
    geometry: new RectangleGeometry({ rectangle: Rectangle.fromDegrees(-100, 30, -90, 40) }),
  }),
  appearance: new MaterialAppearance({
    material: Material.fromType("Checkerboard", {
      lightColor: Color.WHITE, darkColor: Color.BLACK, repeat: new Cartesian2(4, 4),
    }),
  }),
}));

Compositing Sub-Materials (Fabric materials + components)

import { Material, Color } from "cesium";

const compositeMat = new Material({ fabric: {
  materials: {
    gridMaterial: { type: "Grid" },
    colorMaterial: { type: "Color", uniforms: { color: Color.BLUE } },
  },
  components: {
    diffuse: "gridMaterial.diffuse + 0.2 * colorMaterial.diffuse",
    alpha: "min(gridMaterial.alpha, colorMaterial.alpha)",
  },
}});

CustomShader

CustomShader injects user GLSL into Model, Cesium3DTileset, and VoxelPrimitive rendering, with access to vertex attributes, feature IDs, and EXT_structural_metadata.

For shader authoring — struct reference, metadata access, feature IDs, voxel subset, 1.139 breaking changes, and seven worked examples — see the cesiumjs-custom-shader skill. This skill owns the CustomShader integration surface; the authoring depth lives there.

Minimal example:

import { CustomShader, Model } from "cesium";

const shader = new CustomShader({
  fragmentShaderText: `
    void fragmentMain(FragmentInput fsInput, inout czm_modelMaterial material) {
      material.diffuse = vec3(1.0, 0.5, 0.0);
    }
  `,
});
const model = await Model.fromGltfAsync({ url: "./building.glb", customShader: shader });
viewer.scene.primitives.add(model);

ImageBasedLighting

Controls PBR image-based lighting for Model and Cesium3DTileset. imageBasedLightingFactor (Cartesian2) scales diffuse (x) and specular (y) from 0 to 1. Diffuse comes from sphericalHarmonicCoefficients (array of 9 Cartesian3, L0-L2). Specular comes from specularEnvironmentMaps (URL to KTX2 cube map).

import { ImageBasedLighting, Cartesian2, Cartesian3 } from "cesium";

const coefficients = [ // 9 Cartesian3 values for L0..L2 bands
  new Cartesian3(0.35, 0.35, 0.38), new Cartesian3(0.11, 0.11, 0.11),
  new Cartesian3(0.04, 0.04, 0.04), new Cartesian3(-0.08, -0.08, -0.08),
  new Cartesian3(-0.02, -0.02, -0.02), new Cartesian3(0.04, 0.04, 0.04),
  new Cartesian3(-0.06, -0.06, -0.06), new Cartesian3(0.01, 0.01, 0.01),
  new Cartesian3(-0.03, -0.03, -0.03),
];
const ibl = new ImageBasedLighting({
  imageBasedLightingFactor: new Cartesian2(1.0, 1.0),
  sphericalHarmonicCoefficients: coefficients,
  specularEnvironmentMaps: "./environment/specular.ktx2",
});
const model = await Cesium.Model.fromGltfAsync({ url: "./helmet.glb", imageBasedLighting: ibl });
viewer.scene.primitives.add(model);
// Disable: model.imageBasedLighting.imageBasedLightingFactor = new Cartesian2(0.0, 0.0);

Post-Processing

Screen-space pipeline via viewer.scene.postProcessStages (PostProcessStageCollection). Stages execute in order; each reads colorTexture and depthTexture.

Built-in Effects (PostProcessStageLibrary)

createBlurStage() (delta, sigma, stepSize), createDepthOfFieldStage() (focalDistance, delta, sigma, stepSize), createEdgeDetectionStage() (color, length), createSilhouetteStage() (color, length), createBlackAndWhiteStage() (gradations), createBrightnessStage() (brightness), createNightVisionStage(), createLensFlareStage() (intensity, distortion, ghostDispersal, haloWidth).

Collection Stages (Bloom, AO, FXAA, Tonemapping)

Bloom, ambient occlusion, and FXAA are accessed directly on the collection (not via the library). Tonemapping defaults to PBR_NEUTRAL.

import { Tonemapper, PostProcessStageLibrary } from "cesium";

// Bloom
viewer.scene.postProcessStages.bloom.enabled = true;
viewer.scene.postProcessStages.bloom.uniforms.contrast = 128.0;
viewer.scene.postProcessStages.bloom.uniforms.brightness = -0.3;

// Ambient Occlusion (HBAO)
viewer.scene.postProcessStages.ambientOcclusion.enabled = true;
viewer.scene.postProcessStages.ambientOcclusion.uniforms.intensity = 3.0;

// FXAA
viewer.scene.postProcessStages.fxaa.enabled = true;

// Tonemapping: REINHARD, MODIFIED_REINHARD, FILMIC, ACES, PBR_NEUTRAL (default)
viewer.scene.postProcessStages.tonemapper = Tonemapper.ACES;
viewer.scene.postProcessStages.exposure = 1.2; // <1 darker, >1 brighter

// Depth of field (added via library)
const dof = viewer.scene.postProcessStages.add(
  PostProcessStageLibrary.createDepthOfFieldStage()
);
dof.uniforms.focalDistance = 500.0; // meters from camera
dof.uniforms.sigma = 3.8;

Custom PostProcessStage

Custom stages receive colorTexture, depthTexture (sampler2D) and v_textureCoordinates (vec2). Output via out_FragColor. Uniforms can be constants or functions (re-evaluated each frame).

import { PostProcessStage } from "cesium";

const sepia = viewer.scene.postProcessStages.add(new PostProcessStage({
  fragmentShader: `
    uniform sampler2D colorTexture; in vec2 v_textureCoordinates; uniform float intensity;
    void main() {
      vec4 c = texture(colorTexture, v_textureCoordinates);
      float gray = dot(c.rgb, vec3(0.299, 0.587, 0.114));
      out_FragColor = vec4(mix(c.rgb, gray * vec3(1.2, 1.0, 0.8), intensity), c.a);
    }`,
  uniforms: { intensity: () => 0.8 }, // function uniform, re-evaluated each frame
}));

Selected Feature Highlighting

Use czm_selected() in the fragment shader and assign features to stage.selected.

import { PostProcessStage, Color } from "cesium";

const highlight = viewer.scene.postProcessStages.add(new PostProcessStage({
  fragmentShader: `
    uniform sampler2D colorTexture; in vec2 v_textureCoordinates; uniform vec4 highlight;
    void main() {
      vec4 color = texture(colorTexture, v_textureCoordinates);
      if (czm_selected()) {
        out_FragColor = vec4(mix(color.rgb, highlight.rgb, highlight.a), 1.0);
      } else { out_FragColor = color; }
    }`,
  uniforms: { highlight: () => new Color(1.0, 1.0, 0.0, 0.5) },
}));
highlight.selected = [pickedFeature];

PostProcessStageComposite

import { PostProcessStage, PostProcessStageComposite, PostProcessStageLibrary } from "cesium";

const blur = PostProcessStageLibrary.createBlurStage();
const combine = new PostProcessStage({
  fragmentShader: `
    uniform sampler2D colorTexture; uniform sampler2D blurTexture;
    in vec2 v_textureCoordinates;
    void main() {
      vec4 orig = texture(colorTexture, v_textureCoordinates);
      vec4 blurred = texture(blurTexture, v_textureCoordinates);
      out_FragColor = mix(orig, blurred, 0.5);
    }`,
  uniforms: { blurTexture: blur.name }, // reference another stage's output by name
});
viewer.scene.postProcessStages.add(new PostProcessStageComposite({
  stages: [blur, combine],
  inputPreviousStageTexture: false, // both read the original scene texture
}));

Managing Stages

viewer.scene.postProcessStages.remove(sepia); // remove specific stage
dof.enabled = false;                          // disable without removing
viewer.scene.postProcessStages.removeAll();   // remove all custom stages

BlendingState

Predefined blending presets for Appearance.renderState on Primitives.

Preset	Behavior
BlendingState.DISABLED	No blending
BlendingState.ALPHA_BLEND	Standard alpha: src*srcA + dst*(1-srcA)
BlendingState.PRE_MULTIPLIED_ALPHA_BLEND	Premultiplied: src + dst*(1-srcA)
BlendingState.ADDITIVE_BLEND	Additive: src*srcA + dst

import { MaterialAppearance, BlendingState, Material, Color } from "cesium";

const appearance = new MaterialAppearance({
  material: Material.fromType("Color", { color: Color.RED.withAlpha(0.5) }),
  renderState: { depthTest: { enabled: true }, blending: BlendingState.ALPHA_BLEND },
});

Performance Tips

1. Prefer Material.fromType() for built-in types -- cached shader programs avoid recompilation.
2. Use Material.fromTypeAsync() for texture materials to prevent default-texture flicker.
3. Set PostProcessStage.textureScale below 1.0 (e.g., 0.5) to reduce pixels processed in expensive stages.
4. Disable unused built-in stages (bloom.enabled = false) -- enabled stages consume GPU resources.
5. Combine effects in a PostProcessStageComposite to reduce intermediate texture allocations.
6. Minimize PostProcessStage count -- each requires a full-screen draw call and framebuffer.

See Also

• cesiumjs-custom-shader -- GLSL authoring for Model.customShader, Cesium3DTileset.customShader, VoxelPrimitive.customShader (struct reference, metadata, feature IDs)
• cesiumjs-primitives -- Geometry, Appearances, and Material application on Primitive API objects
• cesiumjs-3d-tiles -- Cesium3DTileset loading and styling
• cesiumjs-models-particles -- Model loading and glTF