SensorViewshed

Members

Default Value: new Event()

Default Value: new Event()

Methods

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Example:

const area = sensor.viewshed.getCoverageArea();
if (area) {
  console.log(`Visible: ${area.visibleAreaKm2.toFixed(2)} km²`);
  console.log(`Occluded: ${area.occludedAreaKm2.toFixed(2)} km²`);
}

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Example:

const stats = sensor.viewshed.getCoverageStatistics();
if (stats) {
  console.log(`${stats.visiblePercentage.toFixed(1)}% visible`);
  console.log(`Nearest occluder at ${stats.nearestOcclusionDistance.toFixed(0)} m`);
}

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Example:

const visible = sensor.viewshed.getVisibleEntities(viewer.entities, viewer.clock.currentTime);
console.log(`${visible.length} entities have clear line-of-sight`);

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Examples:

const result = sensor.viewshed.isVisible(Cesium.Cartesian3.fromDegrees(-121.79, 46.854, 4500));
// → { visible: true, distance: 1500, occlusionDistance: 0 }

const results = sensor.viewshed.isVisible([pointA, pointB]);
// → [{ visible: true, ... }, { visible: false, ... }]

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Type Definitions

Properties:

Name	Type	Description
visiblePercentage	number	Percentage of the viewshed footprint with clear line-of-sight (0–100).
occludedPercentage	number	Percentage blocked by terrain or objects (0–100).
totalPixels	number	Total shadow map pixels sampled across all cascades.
visiblePixels	number	Pixels with no obstruction within the sensor radius.
occludedPixels	number	Pixels with an obstruction within the sensor radius.
averageOcclusionDistance	number	Average distance to occluders in metres (occluded pixels only).
nearestOcclusionDistance	number	Distance to the nearest occluder in metres.
farthestOcclusionDistance	number	Distance to the farthest occluder in metres.
sampleStride	number	Highest sampling stride used across the aggregated cascades.
sampledPixels	number	Number of pixels actually sampled across cascades.
estimated	boolean	Whether any aggregate pixel counts were estimated from sampled subsets.

Properties:

Name	Type	Description
totalSamples	number	Number of tracked mask samples accumulated.
minimumOcclusionFrequency	number	Persistence threshold used for classification.
textureSize	number	Width/height of each tracked cascade texture.
totalPixels	number	Total tracked pixels across cascades.
persistentPixels	number	Pixels occluded at or above the persistence threshold.
transientPixels	number	Pixels occluded at least once but below the persistence threshold.
neverOccludedPixels	number	Pixels never observed as occluded.
persistentPercentage	number	Percentage of persistent blind-spot pixels.
transientPercentage	number	Percentage of transiently occluded pixels.
maximumOcclusionFrequency	number	Highest per-pixel occlusion frequency observed.
cascades	Array.<SensorViewshed.CascadeBlindSpotStatistics>	Per-cascade blind-spot summaries.

Properties:

Name	Type	Attributes	Description
cascadeIndex	number		Cascade index.
totalPixels	number		Total tracked pixels in the cascade.
persistentPixels	number		Pixels occluded at or above the persistence threshold.
transientPixels	number		Pixels occluded at least once but below the persistence threshold.
neverOccludedPixels	number		Pixels never observed as occluded.
persistentPercentage	number		Percentage of persistent blind-spot pixels.
transientPercentage	number		Percentage of transiently occluded pixels.
maximumOcclusionFrequency	number		Highest per-pixel occlusion frequency in the cascade.
occlusionFrequencies	Float32Array	<optional>	Optional per-pixel occlusion-frequency buffer.

Properties:

Name	Type	Description
cascadeIndex	number	Cascade index.
totalPixels	number	Total compared pixels in the cascade.
changedPixels	number	Pixels whose occlusion state changed.
becameOccludedPixels	number	Pixels that changed from visible to occluded.
becameVisiblePixels	number	Pixels that changed from occluded to visible.
unchangedPixels	number	Pixels whose occlusion state did not change.
changePercentage	number	Percentage of changed pixels in the cascade.

Properties:

Name	Type	Description
cascadeIndex	number	Cascade index.
visiblePercentage	number	Percentage of the cascade footprint with clear line-of-sight (0–100).
occludedPercentage	number	Percentage blocked by terrain or objects (0–100).
totalPixels	number	Total shadow map pixels sampled in the cascade.
visiblePixels	number	Pixels with no obstruction within the sensor radius.
occludedPixels	number	Pixels with an obstruction within the sensor radius.
averageOcclusionDistance	number	Average distance to occluders in metres (occluded pixels only).
nearestOcclusionDistance	number	Distance to the nearest occluder in metres.
farthestOcclusionDistance	number	Distance to the farthest occluder in metres.
sampleStride	number	Sampling stride used for the cascade analysis.
sampledPixels	number	Number of cascade pixels actually sampled.
estimated	boolean	Whether the cascade pixel counts were estimated from a sampled subset.

Properties:

Name	Type	Description
cascadeIndex	number	Cascade index.
totalPixels	number	Total pixels sampled in the cascade.
deadZonePixels	number	Pixels that reached maximum depth without a hit.
deadZonePercentage	number	Percentage of dead-zone pixels in the cascade.
locations	Array.<SensorViewshed.DeadZoneLocation>	Sampled dead-zone locations retained for the cascade.

Properties:

Name	Type	Description
visibleAreaKm2	number	Visible terrain area in km².
occludedAreaKm2	number	Occluded terrain area in km².
totalAreaKm2	number	Total footprint area in km².
visiblePercentage	number	Visible area as a percentage (0–100).
occludedPercentage	number	Occluded area as a percentage (0–100).
totalSamples	number	Total shadow map pixels analysed.
sampleStride	number	Sampling stride used for the offscreen area pass.
estimated	boolean	Whether the area result was estimated from a sampled subset.

Properties:

Name	Type	Attributes	Description
time	JulianDate	<optional>	Simulation time of the current sample.
previousTime	JulianDate	<optional>	Simulation time of the previous sample.
textureSize	number		Width/height of the compared cascade textures.
totalPixels	number		Total compared pixels across cascades.
changedPixels	number		Pixels whose occlusion state changed.
unchangedPixels	number		Pixels whose occlusion state did not change.
becameOccludedPixels	number		Pixels that changed from visible to occluded.
becameVisiblePixels	number		Pixels that changed from occluded to visible.
changePercentage	number		Percentage of changed pixels across cascades.
changedLocations	Array.<SensorViewshed.CoverageDeltaLocation>		Sampled changed pixel locations.
cascades	Array.<SensorViewshed.CascadeCoverageDelta>		Per-cascade delta summaries.

Properties:

Name	Type	Description
cascadeIndex	number	Cascade index containing the changed pixel.
pixelIndex	number	Flattened pixel index within the cascade.
x	number	Pixel x coordinate.
y	number	Pixel y coordinate.
previousOccluded	boolean	Previous occlusion state.
currentOccluded	boolean	Current occlusion state.

Properties:

Name	Type	Description
time	JulianDate	Simulation time of the snapshot.
visiblePercentage	number	Visible coverage percentage.
occludedPercentage	number	Occluded coverage percentage.
totalPixels	number	Total sampled pixels.
visiblePixels	number	Visible pixels.
occludedPixels	number	Occluded pixels.
averageOcclusionDistance	number	Average distance to occluders in metres.
nearestOcclusionDistance	number	Distance to the nearest occluder in metres.
farthestOcclusionDistance	number	Distance to the farthest occluder in metres.

Properties:

Name	Type	Description
html	string	HTML report document.
data	SensorViewshed.CoverageReportData	Source data used to render the report.

Properties:

Name	Type	Attributes	Description
title	string		Report title.
generatedAt	JulianDate		Report generation time.
sensor	Sensor		Source sensor.
sensorId	string | number | undefined		Source sensor identifier.
coverage	SensorViewshed.CoverageStatistics		Coverage statistics used by the report.
coverageArea	SensorViewshed.CoverageArea	<optional>	Optional coverage-area summary.
deadZones	SensorViewshed.DeadZoneStatistics	<optional>	Optional dead-zone summary.
blindSpots	SensorViewshed.BlindSpotStatistics	<optional>	Optional blind-spot summary.
coverageHistory	Array.<SensorViewshed.CoverageHistoryEntry>		Coverage history snapshots included in the report.

Properties:

Name	Type	Description
visiblePercentage	number	Percentage of the viewshed footprint with clear line-of-sight (0–100).
occludedPercentage	number	Percentage blocked by terrain or objects (0–100).
totalPixels	number	Total shadow map pixels sampled across all cascades.
visiblePixels	number	Pixels with no obstruction within the sensor radius.
occludedPixels	number	Pixels with an obstruction within the sensor radius.
averageOcclusionDistance	number	Average distance to occluders in metres (occluded pixels only).
nearestOcclusionDistance	number	Distance to the nearest occluder in metres.
farthestOcclusionDistance	number	Distance to the farthest occluder in metres.
sampleStride	number	Sampling stride used when reading the coverage result.
sampledPixels	number	Number of pixels actually sampled before any estimation.
estimated	boolean	Whether any pixel counts were estimated from a sampled subset.
cascades	Array.<SensorViewshed.CascadeCoverageStatistics>	Per-cascade statistics.
aggregate	SensorViewshed.AggregateCoverageStatistics	Aggregate statistics across all cascades.

Properties:

Name	Type	Attributes	Description
cascadeIndex	number		Cascade index containing the dead-zone pixel.
pixelIndex	number		Flattened pixel index within the cascade.
x	number		Pixel x coordinate.
y	number		Pixel y coordinate.
distance	number		Endpoint distance used for the sampled location.
direction	Cartesian3		World-space ray direction for the dead-zone sample.
position	Cartesian3		World-space endpoint sampled along the dead-zone ray.
cartographic	Cartographic	<optional>	Cartographic version of the sampled endpoint when available.

Properties:

Name	Type	Description
radius	number	Sensor radius used for dead-zone endpoint reconstruction.
textureSize	number	Width/height of each cascade texture.
totalPixels	number	Total sampled pixels across cascades.
deadZonePixels	number	Total dead-zone pixels across cascades.
deadZonePercentage	number	Percentage of dead-zone pixels across cascades.
locations	Array.<SensorViewshed.DeadZoneLocation>	Sampled dead-zone locations across cascades.
cascades	Array.<SensorViewshed.CascadeDeadZoneStatistics>	Per-cascade dead-zone summaries.

Properties:

Name	Type	Description
cascadeIndex	number	Cascade index.
width	number	Texture width in pixels.
height	number	Texture height in pixels.
data	Float32Array	Decoded depth values.
minimumValue	number	Minimum decoded value in the buffer.
maximumValue	number	Maximum decoded value in the buffer.

Properties:

Name	Type	Description
format	string	Export format ("distance" or "normalized").
radius	number	Sensor radius used when decoding distance values.
textureSize	number	Width/height of each cascade texture.
cascades	Array.<SensorViewshed.DepthBufferCascade>	Decoded depth buffers by cascade.

Properties:

Name	Type	Description
rectangle	object	Rectangle sampled for the analysis. Properties Name Type Description west number West longitude in radians. south number South latitude in radians. east number East longitude in radians. north number North latitude in radians.
resolution	object	Sampled grid resolution. Properties Name Type Description width number Sampled grid width. height number Sampled grid height.
totalSamples	number	Total terrain samples evaluated.
minimumProminence	number	Minimum prominence threshold in metres.
highPoints	Array.<SensorViewshed.HighPointCandidate>	Sorted high-point candidates.

Properties:

Name	Type	Description
index	number	Flattened grid index of the sampled point.
xIndex	number	Grid x index.
yIndex	number	Grid y index.
height	number	Sampled terrain height in metres.
prominence	number	Height difference between this point and its highest neighbor.
cartographic	Cartographic	Cartographic position of the candidate.
position	Cartesian3	World-space position of the candidate.

Properties:

Name	Type	Description
sensor	Sensor	Source sensor.
sensorPosition	Cartesian3	Source sensor position in world coordinates.
sensorCartographic	Cartographic	Source sensor position in cartographic coordinates.
maximumDistance	number	Maximum sweep distance in metres.
sampleStepMeters	number	Distance between terrain samples along each azimuth.
azimuthStepDegrees	number	Angular spacing between azimuth sweeps.
azimuths	Array.<SensorViewshed.HorizonAzimuthSample>	Horizon samples by azimuth.

Properties:

Name	Type	Attributes	Description
azimuthDegrees	number		Sweep azimuth in degrees clockwise from north.
headingRadians	number		Sweep heading in radians.
horizonDistance	number		Distance to the horizon-defining sample in metres.
maximumElevationAngle	number	<optional>	Maximum terrain elevation angle encountered along the sweep.
horizonHeight	number	<optional>	Terrain height of the horizon-defining sample.
horizonCartographic	Cartographic	<optional>	Cartographic position of the horizon-defining sample.

Properties:

Name	Type	Attributes	Description
visible	boolean		Always false for identified occluders.
targetPosition	Cartesian3		The requested target point.
position	Cartesian3		World-space hit position of the blocking occluder.
object	object		Raw object returned by Scene.pickFromRay().
entity	object	<optional>	Entity or feature identifier resolved from the pick result.
primitive	object	<optional>	Primitive resolved from the pick result.
distanceToTarget	number		Distance from the sensor to the target in metres.
pickedDistance	number		Distance from the sensor to the picked occluder hit in metres.
occlusionDistance	number		Occlusion distance reported by isVisible().
occlusionFraction	number		Occlusion distance normalized by distance to the target.
width	number		Pick-ray width used for the occluder lookup.
centerVisibility	SensorViewshed.VisibilityResult | undefined		Visibility result for the target point.

Properties:

Name	Type	Attributes	Description
totalSamples	number		Total evaluated sample points.
overlapSamples	number		Samples covered by at least two sensors.
singleCoverageSamples	number		Samples covered by exactly one sensor.
uncoveredSamples	number		Samples not covered by any sensor.
overlapPercentage	number		Percentage of samples covered by at least two sensors.
sensorIds	Array.<string>		Sensor IDs participating in the analysis.
resolution	object	<optional>	Terrain sampling resolution when generated from a rectangle. Properties Name Type Description width number Sampled grid width. height number Sampled grid height.
samples	Array.<SensorViewshed.OverlapCoverageSample>		Retained overlapping sample locations.

Properties:

Name	Type	Attributes	Description
index	number		Flattened sample index.
point	Cartesian3		World-space sample point.
cartographic	Cartographic	<optional>	Cartographic sample point when available.
visibleSensorIds	Array.<string>		Sensor IDs that reported the point as visible.
overlapCount	number		Number of sensors covering the sample.

Properties:

Name	Type	Description
sensor	Sensor	Candidate sensor.
sensorId	string | number | undefined	Candidate sensor identifier.
viewshed	SensorViewshed	Candidate viewshed instance.
target	Entity | Cartesian3	Evaluated target.
visible	boolean	Whether the candidate met the visibility threshold.
visibleFraction	number	Fraction of samples marked visible.
occlusionDistance	number	Center-point occlusion distance in metres.
distance	number	Sensor-to-target distance in metres.
score	number	Candidate score used for ranking.
visibility	object	Result from checkEntityVisibility().
centerVisibility	SensorViewshed.VisibilityResult | undefined	Result from isVisible() for the target center.

Properties:

Name	Type	Description
bestSensor	Sensor	Highest-ranked sensor.
bestSensorId	string | number | undefined	Highest-ranked sensor identifier.
bestViewshed	SensorViewshed	Highest-ranked viewshed instance.
recommendations	Array.<SensorViewshed.SensorHandoffCandidate>	Ranked candidates in descending score order.

Properties:

Name	Type	Description
sensor	Sensor	Source sensor instance.
sensorId	string | number | undefined	Source sensor identifier.
target	Entity	Target entity instance.
targetId	string | number	Target identifier.
visible	boolean	Whether the target met the visibility threshold.
fraction	number	Visible sample fraction alias.
visibleFraction	number	Visible sample fraction from checkEntityVisibility().
distance	number	Sensor-to-target distance in metres.
visibleCount	number	Number of visible samples.
totalSamples	number	Total samples tested.

Properties:

Name	Type	Attributes	Description
visible	boolean		true if the point has clear line-of-sight from the sensor.
distance	number		Distance from the sensor to the point in metres.
occlusionDistance	number		If occluded, the distance to the nearest terrain occluder in metres. Otherwise 0.
point	Cartesian3	<optional>	The tested point (only present in batch results).