Viewshed

new Cesium.Viewshed(options)
engine/Source/Scene/Viewshed.js 163

A viewshed analyzes visibility from an observer position, showing which areas are visible and which are occluded by terrain or other objects.

Name Type Description

options

object

Object with the following properties:

Name	Type	Default	Description
`scene`	Scene		The scene to add the viewshed to.
`observerPosition`	Cartesian3		The observer position in world coordinates.
`heading`	number	`0.0`	optional The heading angle in radians (0 = north, positive = clockwise).
`pitch`	number	`-CesiumMath.PI_OVER_TWO`	optional The pitch angle in radians (0 = horizontal, negative = down).
`range`	number	`1000.0`	optional The analysis range in meters.
`horizontalFov`	number	`CesiumMath.PI_OVER_TWO`	optional The horizontal field of view in radians.
`verticalFov`	number	`CesiumMath.PI_OVER_TWO`	optional The vertical field of view in radians.
`visibleColor`	Color	`Color.GREEN.withAlpha(0.5)`	optional Color for visible areas.
`occludedColor`	Color	`Color.RED.withAlpha(0.5)`	optional Color for occluded areas.
`visualizationMode`	ViewshedVisualizationMode	`ViewshedVisualizationMode.VISIBILITY`	optional Viewshed coloring mode.
`rfFrequency`	number	`2.4e9`	optional Frequency in Hz for RF path-loss visualization.
`rfAtmosphericLossDbPerKm`	number	`0.0`	optional Atmospheric attenuation rate used by RF path-loss visualization.
`rfOccludedLossDb`	number	`35.0`	optional Additional loss applied to occluded fragments in RF path-loss visualization.
`rfThresholdDb`	number	`140.0`	optional Path-loss threshold separating "good" and "bad" RF coverage colors.
`rfTransitionWidthDb`	number	`6.0`	optional Transition band around the RF threshold. Use 0 for a hard cutoff.
`rfGoodColor`	Color	`Color.GREEN.withAlpha(0.55)`	optional Color for fragments below the RF loss threshold.
`rfBadColor`	Color	`Color.RED.withAlpha(0.55)`	optional Color for fragments above the RF loss threshold.
`displayMode`	ViewshedDisplayMode	`ViewshedDisplayMode.TERRAIN_OVERLAY`	optional How to display the viewshed.
`resolution`	number	`2048`	optional Shadow map resolution (higher = more accurate but slower).
`enabled`	boolean	`true`	optional Whether the viewshed is enabled.

Example:

const viewshed = new Cesium.Viewshed({
  scene: viewer.scene,
  observerPosition: Cesium.Cartesian3.fromDegrees(-122.4, 37.8, 100),
  heading: 0,
  pitch: Cesium.Math.toRadians(-15),
  range: 5000,
  horizontalFov: Cesium.Math.toRadians(90),
  verticalFov: Cesium.Math.toRadians(60)
});

Members

displayMode : ViewshedDisplayMode
engine/Source/Scene/Viewshed.js 530

Gets or sets the display mode.

enabled : boolean
engine/Source/Scene/Viewshed.js 262

Gets or sets whether the viewshed is enabled.

heading : number
engine/Source/Scene/Viewshed.js 299

Gets or sets the heading angle in radians.

horizontalFov : number
engine/Source/Scene/Viewshed.js 350

Gets or sets the horizontal field of view in radians.

observerPosition : Cartesian3
engine/Source/Scene/Viewshed.js 279

Gets or sets the observer position in world coordinates.

occludedColor : Color
engine/Source/Scene/Viewshed.js 401

Gets or sets the color for occluded areas.

pitch : number
engine/Source/Scene/Viewshed.js 316

Gets or sets the pitch angle in radians.

range : number
engine/Source/Scene/Viewshed.js 333

Gets or sets the analysis range in meters.

rfAtmosphericLossDbPerKm : number
engine/Source/Scene/Viewshed.js 446

Gets or sets the atmospheric attenuation rate used by RF viewshed visualization.

rfBadColor : Color
engine/Source/Scene/Viewshed.js 516

Gets or sets the "bad" RF coverage color.

rfFrequency : number
engine/Source/Scene/Viewshed.js 432

Gets or sets the RF frequency used by RF viewshed visualization.

rfGoodColor : Color
engine/Source/Scene/Viewshed.js 502

Gets or sets the "good" RF coverage color.

rfOccludedLossDb : number
engine/Source/Scene/Viewshed.js 460

Gets or sets the occlusion penalty applied in RF viewshed visualization.

rfThresholdDb : number
engine/Source/Scene/Viewshed.js 474

Gets or sets the RF path-loss threshold.

rfTransitionWidthDb : number
engine/Source/Scene/Viewshed.js 488

Gets or sets the transition band around the RF threshold.

readonly shadowMap : ShadowMap
engine/Source/Scene/Viewshed.js 545

Gets the underlying shadow map used for depth comparison.

verticalFov : number
engine/Source/Scene/Viewshed.js 367

Gets or sets the vertical field of view in radians.

visibleColor : Color
engine/Source/Scene/Viewshed.js 384

Gets or sets the color for visible areas.

visualizationMode : ViewshedVisualizationMode
engine/Source/Scene/Viewshed.js 418

Gets or sets the viewshed visualization mode.

Methods

destroy()
engine/Source/Scene/Viewshed.js 653

Destroys the viewshed. Once destroyed, a viewshed should not be used.

isDestroyed() → boolean
engine/Source/Scene/Viewshed.js 646

Returns true if this object was destroyed; otherwise, false.

Returns:

True if this object was destroyed; otherwise, false.

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