cesiumjs-imagery

name	cesiumjs-imagery
description	CesiumJS imagery layers - ImageryProvider, ImageryLayer, ImageryLayerCollection, WMS, WMTS, Bing, OpenStreetMap, ArcGIS, Mapbox, tile discard policies. Use when adding or swapping base map layers, configuring imagery providers, layering multiple map sources, or creating split-screen imagery comparisons.

CesiumJS Imagery Layers

CesiumJS v1.139 -- Imagery providers supply raster tile data rendered on the Globe or draped over a Cesium3DTileset. The three core abstractions are ImageryProvider (fetches tiles), ImageryLayer (display settings), and ImageryLayerCollection (ordered stack on the globe).

ImageryProvider        (abstract -- fetches tile images)
  -> ImageryLayer      (wraps one provider; alpha, brightness, split, etc.)
    -> ImageryLayerCollection  (ordered stack; index 0 = base layer)
      -> Globe / Cesium3DTileset

Layers render bottom-to-top. Index 0 is the base layer, stretched to fill the globe even if its rectangle does not cover the entire world.

Quick Start and ImageryLayer Factories

When creating a viewer for imagery work, disable unneeded widgets so the imagery is the visual focus. Use camera.setView (not flyTo) when you need the camera in position immediately — flyTo animates and may not finish before your code continues.

import { Viewer, ImageryLayer, IonImageryProvider, IonWorldImageryStyle, Math as CesiumMath } from "cesium";

// Clean viewer -- disable widgets that distract from imagery
const viewer = new Viewer("cesiumContainer", {
  animation: false,
  timeline: false,
  navigationHelpButton: false,
  navigationInstructionsInitiallyVisible: false,
});

// Position camera immediately (no animation)
viewer.camera.setView({
  destination: Cesium.Cartesian3.fromDegrees(-73.0, 41.0, 1500000),
  orientation: {
    heading: 0.0,
    pitch: CesiumMath.toRadians(-90), // look straight down
    roll: 0.0,
  },
});

// Explicit base layer choice
const viewer2 = new Viewer("cesiumContainer", {
  baseLayer: ImageryLayer.fromWorldImagery(),
});

// fromProviderAsync -- wraps any async provider; returns ImageryLayer immediately
const nightLayer = ImageryLayer.fromProviderAsync(
  IonImageryProvider.fromAssetId(3812), // Earth at Night
);
nightLayer.alpha = 0.5;
nightLayer.brightness = 2.0;
viewer.imageryLayers.add(nightLayer);

// fromWorldImagery with style override
const roadLayer = ImageryLayer.fromWorldImagery({
  style: IonWorldImageryStyle.ROAD,
});
viewer.imageryLayers.add(roadLayer);

Camera Height Reference for Imagery Scenes

Use camera.setView with these approximate heights:

Scale	Height (m)	Example
Street / block	500–2,000	Downtown intersection
City	5,000–25,000	Washington DC, Paris
Metro area	50,000–200,000	Greater London
Region / state	300,000–1,500,000	Florida, Japan
Continent	3,000,000–8,000,000	Europe, North America

For top-down (map-style) views set pitch: CesiumMath.toRadians(-90). For oblique 3D views set pitch: CesiumMath.toRadians(-35) to CesiumMath.toRadians(-60).

ImageryLayerCollection API

Access via viewer.imageryLayers (same as viewer.scene.imageryLayers).

const layers = viewer.imageryLayers;

layers.add(myLayer);              // add on top
layers.add(myLayer, 0);           // add at index
layers.addImageryProvider(provider); // create layer + add

layers.raise(myLayer);            // move up one
layers.lower(myLayer);            // move down one
layers.raiseToTop(myLayer);       // move to top
layers.lowerToBottom(myLayer);    // move to bottom

layers.remove(myLayer);           // remove and destroy
layers.remove(myLayer, false);    // remove without destroying
layers.removeAll();

const count = layers.length;
const base  = layers.get(0);
const idx   = layers.indexOf(myLayer);
const has   = layers.contains(myLayer);

Events: layerAdded(layer, index), layerRemoved(layer, index), layerMoved(layer, newIndex, oldIndex), layerShownOrHidden(layer, index, show).

ImageryLayer Display Properties

Properties accept a number or a per-tile callback (frameState, layer, x, y, level) => value.

Property	Default	Notes
alpha	1.0	0 = transparent, 1 = opaque
brightness	1.0	< 1 darker, > 1 brighter
contrast	1.0	< 1 lower, > 1 higher
hue	0.0	Shift in radians
saturation	1.0	< 1 desaturated, > 1 oversaturated
gamma	1.0	Gamma correction
show	true	Visibility toggle
splitDirection	SplitDirection.NONE	LEFT, RIGHT, or NONE
nightAlpha / dayAlpha	1.0	Requires Globe.enableLighting

Additional options: rectangle, minimumTerrainLevel / maximumTerrainLevel, cutoutRectangle, colorToAlpha / colorToAlphaThreshold, minificationFilter / magnificationFilter (LINEAR default, or NEAREST).

// Adjust appearance at runtime
layer.alpha = 0.7;
layer.brightness = 1.3;
layer.contrast = 1.5;
layer.saturation = 0.5;
layer.gamma = 1.2;

Swapping the Base Layer

Remove the default base layer and replace it at index 0. The replacement becomes the new base layer, stretched to fill the globe.

import { ImageryLayer, OpenStreetMapImageryProvider } from "cesium";

// Remove default Bing aerial
viewer.imageryLayers.remove(viewer.imageryLayers.get(0));

// Add OSM as new base layer at index 0
const osmLayer = new ImageryLayer(
  new OpenStreetMapImageryProvider({
    url: "https://tile.openstreetmap.org/",
    maximumLevel: 19,
    credit: "OpenStreetMap contributors",
  }),
);
viewer.imageryLayers.add(osmLayer, 0);

Imagery Providers

IonImageryProvider

// Always use fromAssetId (async factory); never call constructor directly
const layer = ImageryLayer.fromProviderAsync(
  IonImageryProvider.fromAssetId(3812),
);
viewer.imageryLayers.add(layer);

OpenStreetMapImageryProvider

Extends UrlTemplateImageryProvider for Slippy tile servers.

const osm = new OpenStreetMapImageryProvider({
  url: "https://tile.openstreetmap.org/",
  maximumLevel: 19,
  credit: "OpenStreetMap contributors",
  // retinaTiles: true,  // request @2x tiles
});
viewer.imageryLayers.addImageryProvider(osm);

UrlTemplateImageryProvider

The most flexible provider. Placeholders: {x}, {y}, {z}, {s}, {reverseX/Y/Z}, {west/south/east/northDegrees}, {west/south/east/northProjected}, {width}, {height}.

import { UrlTemplateImageryProvider, GeographicTilingScheme, buildModuleUrl } from "cesium";

// TMS-style with Geographic tiling
const tms = new UrlTemplateImageryProvider({
  url: buildModuleUrl("Assets/Textures/NaturalEarthII") + "/{z}/{x}/{reverseY}.jpg",
  tilingScheme: new GeographicTilingScheme(),
  maximumLevel: 5,
});
viewer.imageryLayers.addImageryProvider(tms);

// Carto Positron with subdomains
const positron = new UrlTemplateImageryProvider({
  url: "https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png",
  subdomains: "abcd",
  credit: "Map tiles by CartoDB, under CC BY 3.0. Data by OpenStreetMap, under ODbL.",
});

// Custom tags for time-varying data
const custom = new UrlTemplateImageryProvider({
  url: "https://yourserver/{Time}/{z}/{y}/{x}.png",
  customTags: {
    Time: (imageryProvider, x, y, level) => "20240101",
  },
});

WebMapServiceImageryProvider (WMS)

import { WebMapServiceImageryProvider, ImageryLayer, Rectangle } from "cesium";

const wms = new WebMapServiceImageryProvider({
  url: "https://basemap.nationalmap.gov:443/arcgis/services/USGSHydroCached/MapServer/WMSServer",
  layers: "0",
  rectangle: Rectangle.fromDegrees(-180, -90, 180, 90),
  // parameters: { transparent: true, format: "image/png" },
  // crs: "EPSG:4326",  // WMS >= 1.3.0
  // srs: "EPSG:4326",  // WMS 1.1.x
});
viewer.imageryLayers.add(new ImageryLayer(wms));

WebMapTileServiceImageryProvider (WMTS)

Required options: url, layer, style, tileMatrixSetID.

import { WebMapTileServiceImageryProvider, Credit } from "cesium";

const wmts = new WebMapTileServiceImageryProvider({
  url: "https://basemap.nationalmap.gov/arcgis/rest/services/USGSShadedReliefOnly/MapServer/WMTS",
  layer: "USGSShadedReliefOnly",
  style: "default",
  format: "image/jpeg",
  tileMatrixSetID: "default028mm",
  maximumLevel: 19,
  credit: new Credit("U. S. Geological Survey"),
});
viewer.imageryLayers.addImageryProvider(wmts);

ArcGisMapServerImageryProvider

import { ArcGisMapServerImageryProvider, ArcGisMapService, ArcGisBaseMapType, ImageryLayer } from "cesium";

ArcGisMapService.defaultAccessToken = "<YOUR_ARCGIS_TOKEN>";

// From basemap type enum: SATELLITE, OCEANS, HILLSHADE
const arcgis = ImageryLayer.fromProviderAsync(
  ArcGisMapServerImageryProvider.fromBasemapType(ArcGisBaseMapType.SATELLITE),
);
viewer.imageryLayers.add(arcgis);

// From a specific MapServer URL
const streets = ImageryLayer.fromProviderAsync(
  ArcGisMapServerImageryProvider.fromUrl(
    "https://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer",
  ),
);

BingMapsImageryProvider

import { BingMapsImageryProvider, BingMapsStyle, ImageryLayer } from "cesium";

const bing = ImageryLayer.fromProviderAsync(
  BingMapsImageryProvider.fromUrl("https://dev.virtualearth.net", {
    key: "<YOUR_BING_KEY>",
    mapStyle: BingMapsStyle.AERIAL_WITH_LABELS_ON_DEMAND,
  }),
);
viewer.imageryLayers.add(bing);

Styles: AERIAL, AERIAL_WITH_LABELS_ON_DEMAND, ROAD_ON_DEMAND, CANVAS_DARK, CANVAS_LIGHT, CANVAS_GRAY.

MapboxStyleImageryProvider

import { MapboxStyleImageryProvider, ImageryLayer } from "cesium";

const mapbox = new MapboxStyleImageryProvider({
  styleId: "streets-v11",
  accessToken: "<YOUR_MAPBOX_TOKEN>",
  // tilesize: 512, scaleFactor: true  // retina
});
viewer.imageryLayers.add(new ImageryLayer(mapbox));

SingleTileImageryProvider

import { SingleTileImageryProvider, ImageryLayer, Rectangle } from "cesium";

const logo = ImageryLayer.fromProviderAsync(
  SingleTileImageryProvider.fromUrl("/images/overlay.png", {
    rectangle: Rectangle.fromDegrees(-75.0, 28.0, -67.0, 29.75),
  }),
);
viewer.imageryLayers.add(logo);

Split-Screen Comparison

import { ImageryLayer, IonImageryProvider, SplitDirection } from "cesium";

// Add an overlay that only appears on the left side of the split
const nightLayer = ImageryLayer.fromProviderAsync(IonImageryProvider.fromAssetId(3812));
nightLayer.splitDirection = SplitDirection.LEFT;
viewer.imageryLayers.add(nightLayer);

viewer.scene.splitPosition = 0.5; // 0-1 fraction of viewport width

SplitDirection: LEFT (-1), NONE (0), RIGHT (1).

Cutout Rectangle

import { Rectangle } from "cesium";

const cutout = Rectangle.fromDegrees(-90, 20, -70, 40);

// Cut a hole in the base layer to reveal imagery beneath
const base = viewer.imageryLayers.get(0);
base.cutoutRectangle = cutout;

Color-to-Alpha

import { Color } from "cesium";

const baseLayer = viewer.imageryLayers.get(0);
baseLayer.colorToAlpha = new Color(0.0, 0.016, 0.059); // dark ocean blue
baseLayer.colorToAlphaThreshold = 0.2; // tolerance (0-1)

Draping Imagery on 3D Tiles

import { Cesium3DTileset, ImageryLayer, IonImageryProvider } from "cesium";

const tileset = await Cesium3DTileset.fromUrl("/path/to/tileset.json");
viewer.scene.primitives.add(tileset);

const labelLayer = ImageryLayer.fromProviderAsync(
  IonImageryProvider.fromAssetId(2411391),
);
tileset.imageryLayers.add(labelLayer); // drape on tileset, not globe
labelLayer.show = false; // toggle off

Debugging Providers

import { TileCoordinatesImageryProvider, GridImageryProvider, ImageryLayer, Color } from "cesium";

// Show x/y/level labels on every tile
viewer.imageryLayers.add(new ImageryLayer(
  new TileCoordinatesImageryProvider({ color: Color.YELLOW }),
));
// Wireframe grid overlay
viewer.imageryLayers.add(new ImageryLayer(new GridImageryProvider()));

Tile Discard Policies

Policy	Behavior
DiscardEmptyTileImagePolicy	Discards zero-byte images (Bing Maps default)
DiscardMissingTileImagePolicy	Compares pixels against a known "missing" tile
NeverTileDiscardPolicy	Never discards (use when server always returns valid tiles)

import { NeverTileDiscardPolicy, UrlTemplateImageryProvider } from "cesium";

const provider = new UrlTemplateImageryProvider({
  url: "https://my-server/{z}/{x}/{y}.png",
  tileDiscardPolicy: new NeverTileDiscardPolicy(),
});

Error Handling

const layer = ImageryLayer.fromProviderAsync(IonImageryProvider.fromAssetId(3812));
viewer.imageryLayers.add(layer);

// Provider creation failure
layer.errorEvent.addEventListener((error) => {
  console.error("Layer creation failed:", error);
});

// Provider resolved -- listen for per-tile errors
layer.readyEvent.addEventListener((provider) => {
  provider.errorEvent.addEventListener((tileError) => {
    console.warn("Tile error:", tileError.message);
  });
});

Time-Dynamic WMTS

Pass clock and times (a TimeIntervalCollection) for time-varying layers.

import { WebMapTileServiceImageryProvider, TimeIntervalCollection, JulianDate, Credit } from "cesium";

const times = TimeIntervalCollection.fromIso8601({
  iso8601: "2015-07-30/2017-06-16/P1D",
  dataCallback: (interval) => ({ Time: JulianDate.toIso8601(interval.start) }),
});
const weather = new WebMapTileServiceImageryProvider({
  url: "https://gibs.earthdata.nasa.gov/wmts/epsg4326/best/AMSR2_Snow_Water_Equivalent/default/{Time}/{TileMatrixSet}/{TileMatrix}/{TileRow}/{TileCol}.png",
  layer: "AMSR2_Snow_Water_Equivalent",  style: "default",
  tileMatrixSetID: "2km",  maximumLevel: 5,  format: "image/png",
  clock: viewer.clock,  times: times,
  credit: new Credit("NASA Global Imagery Browse Services for EOSDIS"),
});
viewer.imageryLayers.addImageryProvider(weather);

Performance Tips

1. Limit simultaneous layers -- 2-3 is typical; each layer multiplies tile requests and GPU texture memory.
2. Set hasAlphaChannel: false on opaque providers to reduce memory and upload time.
3. Use minimumTerrainLevel / maximumTerrainLevel to skip tile fetches at irrelevant zoom levels.
4. Prefer ImageryLayer.fromProviderAsync over manual await -- avoids blank globe during provider load.
5. Set tight rectangle bounds on regional providers to prevent out-of-extent tile requests.
6. Reuse provider instances -- remove with destroy: false and re-add instead of recreating.
7. Use NeverTileDiscardPolicy when tiles are always valid; pixel comparison adds overhead.
8. Choose NEAREST filtering only for classified raster data; LINEAR (default) is faster.

See Also

• cesiumjs-viewer-setup -- Viewer constructor, Ion token, createWorldImageryAsync
• cesiumjs-terrain-environment -- Globe, terrain providers, atmosphere, lighting