public final class TerrainAzimuthElevationMask extends Object
TerrainProvider.AzimuthElevationMask| Modifier and Type | Method and Description |
|---|---|
static AzimuthElevationMask |
compute(TerrainProvider provider,
Cartographic observerPosition,
int numberOfAzimuthSteps,
double stepSize,
double maximumSearchAngle)
Computes an azimuth-elevation mask from the specified terrain provider.
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static AzimuthElevationMask |
compute(TerrainProvider provider,
Cartographic observerPosition,
int numberOfAzimuthSteps,
double stepSize,
double maximumSearchAngle,
ITrackCalculationProgress tracker)
Computes an azimuth-elevation mask from the specified terrain provider with progress tracking.
|
static AzimuthElevationMask |
compute(TerrainProvider provider,
double minimumTerrainHeight,
double maximumTerrainHeight,
Cartographic observerPosition,
int numberOfAzimuthSteps,
double stepSize,
double maximumSearchAngle)
Computes an azimuth-elevation mask from the specified terrain provider.
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static AzimuthElevationMask |
compute(TerrainProvider provider,
double minimumTerrainHeight,
double maximumTerrainHeight,
Cartographic observerPosition,
int numberOfAzimuthSteps,
double stepSize,
double maximumSearchAngle,
ITrackCalculationProgress tracker)
Computes an azimuth-elevation mask from the specified terrain provider with progress tracking.
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static DelayedTerrainAzimuthElevationMask |
createDelayedMask(TerrainProvider provider,
Cartographic observerPosition,
int numberOfAzimuthSteps,
double stepSize,
double maximumSearchAngle)
Creates an azimuth-elevation mask which can compute its values dynamically from the specified terrain provider.
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static DelayedTerrainAzimuthElevationMask |
createDelayedMask(TerrainProvider provider,
double minimumTerrainHeight,
double maximumTerrainHeight,
Cartographic observerPosition,
int numberOfAzimuthSteps,
double stepSize,
double maximumSearchAngle)
Creates an azimuth-elevation mask which can compute its values dynamically from the specified terrain provider.
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public static DelayedTerrainAzimuthElevationMask createDelayedMask(TerrainProvider provider, @Nonnull Cartographic observerPosition, int numberOfAzimuthSteps, double stepSize, double maximumSearchAngle)
This method works by casting a ray out from the observerPosition in a number of directions to
determine the minimum elevation angle that is visible above the terrain in that direction. More specifically,
the various distances at which the minimum elevation angle increases in that direction are determined.
Selecting values for numberOfAzimuthSteps, stepSize, and
maximumSearchAngle requires making a trade-off between the accuracy of the result and the time
to compute it. The ideal values to use depend on the specifics of the problem being solved and the
nature of the terrain data employed.
numberOfAzimuthSteps is the number of rays to cast out from the observerPosition
in computing the mask. A value of 360 casts a ray for each degree, and is a reasonable value to use. Notice that
when a value of 360 is used, the count of elevation masks will be 361 because it contains the elevation for both
0 and 360. The elevation data for 360 copies data from 0 with the exception of the azimuth for efficiency.
stepSize is the distance between steps along the ray, in radians. A reasonable value for this
parameter would sample approximately three times per terrain grid cell, or 1/3 of the smallest of
DeltaLongitude (get / set) and DeltaLatitude (get / set).
maximumSearchAngle is the maximum angle, in radians, to move along each ray. In other words,
this parameter indicates the stopping point for sampling along the ray. A reasonable value will take into account
the difference between the maximum and minimum heights of terrain provided by provider and
potentially how close together the minimum and maximum heights are located.
The following example shows one way this value might be chosen:
double approximateHeightOfMtEverest = 8850.0;
double semimajorAxisLength = WorldGeodeticSystem1984.getShape().getSemimajorAxisLength();
double maximumSearchAngle = Math.acos(semimajorAxisLength / (semimajorAxisLength + approximateHeightOfMtEverest));provider - The source of terrain from which to compute the mask.observerPosition - The planetodetic position of the stationary observer around which the mask is computed.numberOfAzimuthSteps - The number of azimuth steps to use to compute the mask.
This will define the resolution of the mask around the horizon.stepSize - The size of the step along each azimuth ray, in radians.maximumSearchAngle - The maximum angle, in radians, to move along each azimuth ray in constructing the mask.ArgumentOutOfRangeException - Thrown if numberOfAzimuthSteps is less than or equal to zero.public static DelayedTerrainAzimuthElevationMask createDelayedMask(TerrainProvider provider, double minimumTerrainHeight, double maximumTerrainHeight, @Nonnull Cartographic observerPosition, int numberOfAzimuthSteps, double stepSize, double maximumSearchAngle)
This method works by casting a ray out from the observerPosition in a number of directions to
determine the minimum elevation angle that is visible above the terrain in that direction. More specifically,
the various distances at which the minimum elevation angle increases in that direction are determined.
Selecting values for numberOfAzimuthSteps, stepSize, and
maximumSearchAngle requires making a trade-off between the accuracy of the result and the time
to compute it. The ideal values to use depend on the specifics of the problem being solved and the
nature of the terrain data employed.
numberOfAzimuthSteps is the number of rays to cast out from the observerPosition
in computing the mask. A value of 360 casts a ray for each degree, and is a reasonable value to use. Notice that
when a value of 360 is used, the count of elevation masks will be 361 because it contains the elevation for both
0 and 360. The elevation data for 360 copies data from 0 with the exception of the azimuth for efficiency.
stepSize is the distance between steps along the ray, in radians. A reasonable value for this
parameter would sample approximately three times per terrain grid cell, or 1/3 of the smallest of
DeltaLongitude (get / set) and DeltaLatitude (get / set).
maximumSearchAngle is the maximum angle, in radians, to move along each ray. In other words,
this parameter indicates the stopping point for sampling along the ray. A reasonable value will take into account
the difference between the maximum and minimum heights of terrain provided by provider and
potentially how close together the minimum and maximum heights are located.
The following example shows one way this value might be chosen:
double approximateHeightOfMtEverest = 8850.0;
double semimajorAxisLength = WorldGeodeticSystem1984.getShape().getSemimajorAxisLength();
double maximumSearchAngle = Math.acos(semimajorAxisLength / (semimajorAxisLength + approximateHeightOfMtEverest));provider - The source of terrain from which to compute the mask.minimumTerrainHeight - The minimum height in meters that can be returned by the
TerrainProvider's
TerrainProvider.getHeightRelativeToShape(double, double) method.
Setting this value lower than necessary will not affect the results, but it will decrease
performance. Setting it too high can cause incorrect results.maximumTerrainHeight - The maximum height in meters that can be returned by the
TerrainProvider's
TerrainProvider.getHeightRelativeToShape(double, double) method.
Setting this value higher than necessary will not affect the results, but it will decrease
performance. Setting it too low can cause incorrect results.observerPosition - The planetodetic position of the stationary observer around which the mask is computed.numberOfAzimuthSteps - The number of azimuth steps to use to compute the mask.
This will define the resolution of the mask around the horizon.stepSize - The size of the step along each azimuth ray, in radians.maximumSearchAngle - The maximum angle, in radians, to move along each azimuth ray in constructing the mask.ArgumentOutOfRangeException - Thrown if numberOfAzimuthSteps is less than or equal to zero.public static AzimuthElevationMask compute(@Nonnull TerrainProvider provider, @Nonnull Cartographic observerPosition, int numberOfAzimuthSteps, double stepSize, double maximumSearchAngle)
This method works by casting a ray out from the observerPosition in a number of directions to
determine the minimum elevation angle that is visible above the terrain in that direction. More specifically,
the various distances at which the minimum elevation angle increases in that direction are determined.
Selecting values for numberOfAzimuthSteps, stepSize, and
maximumSearchAngle requires making a trade-off between the accuracy of the result and the time
to compute it. The ideal values to use depend on the specifics of the problem being solved and the
nature of the terrain data employed.
numberOfAzimuthSteps is the number of rays to cast out from the observerPosition
in computing the mask. A value of 360 casts a ray for each degree, and is a reasonable value to use. Notice that
when a value of 360 is used, the count of elevation masks will be 361 because it contains the elevation for both
0 and 360. The elevation data for 360 copies data from 0 with the exception of the azimuth for efficiency.
stepSize is the distance between steps along the ray, in radians. A reasonable value for this
parameter would sample approximately three times per terrain grid cell, or 1/3 of the smallest of
DeltaLongitude (get / set) and DeltaLatitude (get / set).
maximumSearchAngle is the maximum angle, in radians, to move along each ray. In other words,
this parameter indicates the stopping point for sampling along the ray. A reasonable value will take into account
the difference between the maximum and minimum heights of terrain provided by provider and
potentially how close together the minimum and maximum heights are located.
The following example shows one way this value might be chosen:
double approximateHeightOfMtEverest = 8850.0;
double semimajorAxisLength = WorldGeodeticSystem1984.getShape().getSemimajorAxisLength();
double maximumSearchAngle = Math.acos(semimajorAxisLength / (semimajorAxisLength + approximateHeightOfMtEverest));provider - The source of terrain from which to compute the mask.observerPosition - The planetodetic position of the stationary observer around which the mask is computed.numberOfAzimuthSteps - The number of azimuth steps to use to compute the mask.stepSize - The size of the step along each azimuth ray, in radians.maximumSearchAngle - The maximum angle, in radians, to move along each azimuth ray in constructing the mask.ArgumentNullException - Thrown if provider is null.ArgumentOutOfRangeException - Thrown if numberOfAzimuthSteps is less than or equal to zero.public static AzimuthElevationMask compute(@Nonnull TerrainProvider provider, @Nonnull Cartographic observerPosition, int numberOfAzimuthSteps, double stepSize, double maximumSearchAngle, @Nullable ITrackCalculationProgress tracker)
This method works by casting a ray out from the observerPosition in a number of directions to
determine the minimum elevation angle that is visible above the terrain in that direction. More specifically,
the various distances at which the minimum elevation angle increases in that direction are determined.
Selecting values for numberOfAzimuthSteps, stepSize, and
maximumSearchAngle requires making a trade-off between the accuracy of the result and the time
to compute it. The ideal values to use depend on the specifics of the problem being solved and the
nature of the terrain data employed.
numberOfAzimuthSteps is the number of rays to cast out from the observerPosition
in computing the mask. A value of 360 casts a ray for each degree, and is a reasonable value to use. Notice that
when a value of 360 is used, the count of elevation masks will be 361 because it contains the elevation for both
0 and 360. The elevation data for 360 copies data from 0 with the exception of the azimuth for efficiency.
stepSize is the distance between steps along the ray, in radians. A reasonable value for this
parameter would sample approximately three times per terrain grid cell, or 1/3 of the smallest of
DeltaLongitude (get / set) and DeltaLatitude (get / set).
maximumSearchAngle is the maximum angle, in radians, to move along each ray. In other words,
this parameter indicates the stopping point for sampling along the ray. A reasonable value will take into account
the difference between the maximum and minimum heights of terrain provided by provider and
potentially how close together the minimum and maximum heights are located.
The following example shows one way this value might be chosen:
double approximateHeightOfMtEverest = 8850.0;
double semimajorAxisLength = WorldGeodeticSystem1984.getShape().getSemimajorAxisLength();
double maximumSearchAngle = Math.acos(semimajorAxisLength / (semimajorAxisLength + approximateHeightOfMtEverest));provider - The source of terrain from which to compute the mask.observerPosition - The planetodetic position of the stationary observer around which the mask is computed.numberOfAzimuthSteps - The number of azimuth steps to use to compute the mask.stepSize - The size of the step along each azimuth ray, in radians.maximumSearchAngle - The maximum angle, in radians, to move along each azimuth ray in constructing the mask.tracker - The object to which progress is reported and that is able to cancel this operation before it is complete, or null.
When reporting progress, the 'additionalInformation' parameter to ITrackCalculationProgress.reportProgress(int, java.lang.Object) will be null.ArgumentNullException - Thrown if provider is null.ArgumentOutOfRangeException - Thrown if numberOfAzimuthSteps is less than or equal to zero.public static AzimuthElevationMask compute(@Nonnull TerrainProvider provider, double minimumTerrainHeight, double maximumTerrainHeight, @Nonnull Cartographic observerPosition, int numberOfAzimuthSteps, double stepSize, double maximumSearchAngle)
This method works by casting a ray out from the observerPosition in a number of directions to
determine the minimum elevation angle that is visible above the terrain in that direction. More specifically,
the various distances at which the minimum elevation angle increases in that direction are determined.
Selecting values for numberOfAzimuthSteps, stepSize, and
maximumSearchAngle requires making a trade-off between the accuracy of the result and the time
to compute it. The ideal values to use depend on the specifics of the problem being solved and the
nature of the terrain data employed.
numberOfAzimuthSteps is the number of rays to cast out from the observerPosition
in computing the mask. A value of 360 casts a ray for each degree, and is a reasonable value to use. Notice that
when a value of 360 is used, the count of elevation masks will be 361 because it contains the elevation for both
0 and 360. The elevation data for 360 copies data from 0 with the exception of the azimuth for efficiency.
stepSize is the distance between steps along the ray, in radians. A reasonable value for this
parameter would sample approximately three times per terrain grid cell, or 1/3 of the smallest of
DeltaLongitude (get / set) and DeltaLatitude (get / set).
maximumSearchAngle is the maximum angle, in radians, to move along each ray. In other words,
this parameter indicates the stopping point for sampling along the ray. A reasonable value will take into account
the difference between the maximum and minimum heights of terrain provided by provider and
potentially how close together the minimum and maximum heights are located.
The following example shows one way this value might be chosen:
double approximateHeightOfMtEverest = 8850.0;
double semimajorAxisLength = WorldGeodeticSystem1984.getShape().getSemimajorAxisLength();
double maximumSearchAngle = Math.acos(semimajorAxisLength / (semimajorAxisLength + approximateHeightOfMtEverest));provider - The source of terrain from which to compute the mask.minimumTerrainHeight - The minimum height in meters that can be returned by the
TerrainProvider's
TerrainProvider.getHeightRelativeToShape(double, double) method.
Setting this value lower than necessary will not affect the results, but it will decrease
performance. Setting it too high can cause incorrect results.maximumTerrainHeight - The maximum height in meters that can be returned by the
TerrainProvider's
TerrainProvider.getHeightRelativeToShape(double, double) method.
Setting this value higher than necessary will not affect the results, but it will decrease
performance. Setting it too low can cause incorrect results.observerPosition - The planetodetic position of the stationary observer around which the mask is computed.numberOfAzimuthSteps - The number of azimuth steps to use to compute the mask.stepSize - The size of the step along each azimuth ray, in radians.maximumSearchAngle - The maximum angle, in radians, to move along each azimuth ray in constructing the mask.ArgumentNullException - Thrown if provider is null.ArgumentOutOfRangeException - Thrown if numberOfAzimuthSteps is less than or equal to zero.public static AzimuthElevationMask compute(@Nonnull TerrainProvider provider, double minimumTerrainHeight, double maximumTerrainHeight, @Nonnull Cartographic observerPosition, int numberOfAzimuthSteps, double stepSize, double maximumSearchAngle, @Nullable ITrackCalculationProgress tracker)
This method works by casting a ray out from the observerPosition in a number of directions to
determine the minimum elevation angle that is visible above the terrain in that direction. More specifically,
the various distances at which the minimum elevation angle increases in that direction are determined.
Selecting values for numberOfAzimuthSteps, stepSize, and
maximumSearchAngle requires making a trade-off between the accuracy of the result and the time
to compute it. The ideal values to use depend on the specifics of the problem being solved and the
nature of the terrain data employed.
numberOfAzimuthSteps is the number of rays to cast out from the observerPosition
in computing the mask. A value of 360 casts a ray for each degree, and is a reasonable value to use. Notice that
when a value of 360 is used, the count of elevation masks will be 361 because it contains the elevation for both
0 and 360. The elevation data for 360 copies data from 0 with the exception of the azimuth for efficiency.
stepSize is the distance between steps along the ray, in radians. A reasonable value for this
parameter would sample approximately three times per terrain grid cell, or 1/3 of the smallest of
DeltaLongitude (get / set) and DeltaLatitude (get / set).
maximumSearchAngle is the maximum angle, in radians, to move along each ray. In other words,
this parameter indicates the stopping point for sampling along the ray. A reasonable value will take into account
the difference between the maximum and minimum heights of terrain provided by provider and
potentially how close together the minimum and maximum heights are located.
The following example shows one way this value might be chosen:
double approximateHeightOfMtEverest = 8850.0;
double semimajorAxisLength = WorldGeodeticSystem1984.getShape().getSemimajorAxisLength();
double maximumSearchAngle = Math.acos(semimajorAxisLength / (semimajorAxisLength + approximateHeightOfMtEverest));provider - The source of terrain from which to compute the mask.minimumTerrainHeight - The minimum height in meters that can be returned by the
TerrainProvider's
TerrainProvider.getHeightRelativeToShape(double, double) method.
Setting this value lower than necessary will not affect the results, but it will decrease
performance. Setting it too high can cause incorrect results.maximumTerrainHeight - The maximum height in meters that can be returned by the
TerrainProvider's
TerrainProvider.getHeightRelativeToShape(double, double) method.
Setting this value higher than necessary will not affect the results, but it will decrease
performance. Setting it too low can cause incorrect results.observerPosition - The planetodetic position of the stationary observer around which the mask is computed.numberOfAzimuthSteps - The number of azimuth steps to use to compute the mask.stepSize - The size of the step along each azimuth ray, in radians.maximumSearchAngle - The maximum angle, in radians, to move along each azimuth ray in constructing the mask.tracker - The object to which progress is reported and that is able to cancel this operation before it is complete, or null.
When reporting progress, the 'additionalInformation' parameter to ITrackCalculationProgress.reportProgress(int, java.lang.Object) will be null.ArgumentNullException - Thrown if provider is null.ArgumentOutOfRangeException - Thrown if numberOfAzimuthSteps is less than or equal to zero.