/// <summary>
/// Create a Platform for the requested satellite using a TLE for position.
/// The satellite will be visually represented by a labeled glTF model,
/// the satellite's orbit will be shown, and vectors will be drawn for
/// the body axes of the satellite, plus a vector indicating the direction
/// of the sun.
/// </summary>
private void CreateSatellite()
{
// Get the current TLE for the given satellite identifier.
var tleList = TwoLineElementSetHelper.GetTles(m_satelliteIdentifier, JulianDate.Now);
// Use the epoch of the first TLE, since the TLE may have been loaded from offline data.
m_epoch = tleList[0].Epoch;
// Propagate the TLE and use that as the satellite's location point.
var locationPoint = new Sgp4Propagator(tleList).CreatePoint();
m_satellite = new Platform
{
Name = "Satellite " + m_satelliteIdentifier,
LocationPoint = locationPoint,
// Orient the satellite using Vehicle Velocity Local Horizontal (VVLH) axes.
OrientationAxes = new AxesVehicleVelocityLocalHorizontal(m_earth.FixedFrame, locationPoint),
};
// Set the identifier for the satellite in the CZML document.
m_satellite.Extensions.Add(new IdentifierExtension(m_satelliteIdentifier));
// Configure a glTF model for the satellite.
m_satellite.Extensions.Add(new ModelGraphicsExtension(new ModelGraphics
{
// Link to a binary glTF file.
Model = new CesiumResource(GetModelUri("satellite.glb"), CesiumResourceBehavior.LinkTo),
// By default, Cesium plays all animations in the model simultaneously, which is not desirable.
RunAnimations = false,
}));
// Configure a label for the satellite.
m_satellite.Extensions.Add(new LabelGraphicsExtension(new LabelGraphics
{
// Use the name of the satellite as the text of the label.
Text = m_satellite.Name,
// Change the color of the label after 12 hours. This demonstrates specifying that
// a value varies over time using intervals.
FillColor = new TimeIntervalCollection <Color>
{
// Green for the first half day...
new TimeInterval <Color>(JulianDate.MinValue, m_epoch.AddDays(0.5), Color.Green, true, false),
// Red thereafter.
new TimeInterval <Color>(m_epoch.AddDays(0.5), JulianDate.MaxValue, Color.Red, false, true),
},
// Only show label when camera is far enough from the satellite,
// to avoid visually clashing with the model.
DistanceDisplayCondition = new Bounds(1000.0, double.MaxValue),
}));
// Configure graphical display of the orbital path of the satellite.
m_satellite.Extensions.Add(new PathGraphicsExtension(new PathGraphics
{
// Configure the visual appearance of the line.
Material = new PolylineOutlineMaterialGraphics
{
Color = Color.White,
OutlineWidth = 1.0,
OutlineColor = Color.Black,
},
Width = 2.0,
// Lead and Trail time indicate how much of the path to render.
LeadTime = Duration.FromMinutes(44.0).TotalSeconds,
TrailTime = Duration.FromMinutes(44.0).TotalSeconds,
}));
// Create vectors for the X, Y, and Z axes of the satellite.
m_satelliteXAxis = CreateAxesVector(m_satellite, CartesianElement.X, Color.Green, "SatelliteX");
m_satelliteYAxis = CreateAxesVector(m_satellite, CartesianElement.Y, Color.Red, "SatelliteY");
m_satelliteZAxis = CreateAxesVector(m_satellite, CartesianElement.Z, Color.Blue, "SatelliteZ");
// Create a vector from the satellite to the Sun.
// Compute the vector from the satellite's location to the Sun's center of mass.
var sunCenterOfMassPoint = CentralBodiesFacet.GetFromContext().Sun.CenterOfMassPoint;
var vectorSatelliteToSun = new VectorTrueDisplacement(m_satellite.LocationPoint, sunCenterOfMassPoint);
// Create the visual vector.
m_satelliteSunVector = new GraphicalVector
{
LocationPoint = m_satellite.LocationPoint,
Vector = vectorSatelliteToSun,
VectorGraphics = new VectorGraphics
{
Length = 5.0,
Color = Color.Yellow,
},
};
// Set the identifier for the vector in the CZML document.
m_satelliteSunVector.Extensions.Add(new IdentifierExtension("SunVector"));
// Orient the solar panels on the satellite model to point at the sun.
var satelliteYVector = m_satellite.OrientationAxes.GetVectorElement(CartesianElement.Y);
// allow only Z axis to rotate to follow sun vector. Constrain sun vector to Y, and satellite Y vector to X.
var constrainedAxes = new AxesAlignedConstrained(satelliteYVector, AxisIndicator.First, vectorSatelliteToSun, AxisIndicator.Second);
// Satellite axes are Vehicle Velocity Local Horizontal (VVLH) axes, where X is forward and Z is down,
// but Cesium model axes are Z forward, Y up. So, create an axes rotates to the Cesium model axes.
var offset = new UnitQuaternion(new ElementaryRotation(AxisIndicator.First, -Math.PI / 2)) *
new UnitQuaternion(new ElementaryRotation(AxisIndicator.Third, Math.PI / 2));
var cesiumModelAxes = new AxesFixedOffset(m_satellite.OrientationAxes, offset);
// The rotation will be from the Cesium model axes to the constrained axes.
var solarPanelRotationAxes = new AxesInAxes(constrainedAxes, cesiumModelAxes);
// Add a node transformation to rotate the SolarPanels node of the model.
m_satellite.Extensions.GetByType <ModelGraphicsExtension>().ModelGraphics.NodeTransformations = new Dictionary <string, NodeTransformationGraphics>
{
{
"SolarPanels", new NodeTransformationGraphics
{
Rotation = new AxesCesiumProperty(solarPanelRotationAxes)
}
}
};
}
/// <summary>
/// Create an aircraft with two sensors.
/// The aircraft will be visually represented by a labeled glTF model.
/// </summary>
private void CreateAircraft()
{
// Define waypoints for the aircraft's path and use the propagated point as the location point.
Cartographic point1 = new Cartographic(Trig.DegreesToRadians(-122.0), Trig.DegreesToRadians(46.3), 4000.0);
Cartographic point2 = new Cartographic(Trig.DegreesToRadians(-122.28), Trig.DegreesToRadians(46.25), 4100.0);
Cartographic point3 = new Cartographic(Trig.DegreesToRadians(-122.2), Trig.DegreesToRadians(46.1), 6000.0);
Cartographic point4 = new Cartographic(Trig.DegreesToRadians(-121.5), Trig.DegreesToRadians(46.0), 7000.0);
Waypoint waypoint1 = new Waypoint(m_epoch, point1, 20.0, 0.0);
Waypoint waypoint2 = new Waypoint(waypoint1, m_earth.Shape, point2, 20.0);
Waypoint waypoint3 = new Waypoint(waypoint2, m_earth.Shape, point3, 20.0);
Waypoint waypoint4 = new Waypoint(waypoint3, m_earth.Shape, point4, 20.0);
var waypointPropagator = new WaypointPropagator(m_earth, waypoint1, waypoint2, waypoint3, waypoint4);
var locationPoint = waypointPropagator.CreatePoint();
m_aircraft = new Platform
{
Name = "Aircraft",
LocationPoint = locationPoint,
OrientationAxes = new AxesVehicleVelocityLocalHorizontal(m_earth.FixedFrame, locationPoint),
};
// Set the identifier for the aircraft in the CZML document.
m_aircraft.Extensions.Add(new IdentifierExtension("Aircraft"));
// Hermite interpolation works better for aircraft-like vehicles.
m_aircraft.Extensions.Add(new CesiumPositionExtension
{
InterpolationAlgorithm = CesiumInterpolationAlgorithm.Hermite
});
// Configure a glTF model for the aircraft.
m_aircraft.Extensions.Add(new ModelGraphicsExtension(new ModelGraphics
{
// Link to a binary glTF file.
Model = new CesiumResource(GetModelUri("aircraft.glb"), CesiumResourceBehavior.LinkTo),
// Flip the model visually to point Z in the correct direction.
NodeTransformations = new Dictionary <string, NodeTransformationGraphics>
{
{
"Aircraft", new NodeTransformationGraphics
{
Rotation = new UnitQuaternion(new ElementaryRotation(AxisIndicator.Third, Math.PI))
}
}
},
RunAnimations = false,
}));
// Show the path of the aircraft.
m_aircraft.Extensions.Add(new PathGraphicsExtension(new PathGraphics
{
Width = 2.0,
LeadTime = Duration.FromHours(1.0).TotalSeconds,
TrailTime = Duration.FromHours(1.0).TotalSeconds,
Material = new PolylineOutlineMaterialGraphics
{
Color = Color.White,
OutlineColor = Color.Black,
OutlineWidth = 1.0,
},
}));
// Configure label for the aircraft.
m_aircraft.Extensions.Add(new LabelGraphicsExtension(new LabelGraphics
{
Text = m_aircraft.Name,
// Change label color over time.
FillColor = new TimeIntervalCollection <Color>
{
// Green by default...
TimeInterval.Infinite.AddData(Color.Green),
// Red between first and second waypoints.
new TimeInterval <Color>(waypoint1.Date, waypoint2.Date, Color.Red),
},
// Only show label when camera is far enough from the aircraft,
// to avoid visually clashing with the model.
DistanceDisplayCondition = new Bounds(1000.0, double.MaxValue),
}));
// Define a description for the aircraft which will be shown when selected in Cesium.
m_aircraft.Extensions.Add(new DescriptionExtension(new Description("Aircraft with two offset sensors")));
// Create 30 degree simple conic sensor definition
var sensorCone = new ComplexConic();
sensorCone.SetHalfAngles(0.0, Trig.DegreesToRadians(15));
sensorCone.SetClockAngles(Trig.DegreesToRadians(20), Trig.DegreesToRadians(50));
sensorCone.Radius = double.PositiveInfinity;
// Create a sensor pointing "forward".
// Position sensor underneath the wing.
var sensorOneLocationPoint = new PointFixedOffset(m_aircraft.ReferenceFrame, new Cartesian(-3.0, 8.0, 0.0));
var sensorAxesOne = new AxesAlignedConstrained(m_aircraft.OrientationAxes.GetVectorElement(CartesianElement.Z), AxisIndicator.Third,
m_aircraft.OrientationAxes.GetVectorElement(CartesianElement.X), AxisIndicator.First);
// This rotation points the z-axis of the volume back along the x-axis of the ellipsoid.
var rotationOne = new UnitQuaternion(new ElementaryRotation(AxisIndicator.Second, Constants.HalfPi / 4));
m_aircraftSensorOne = new Platform
{
LocationPoint = sensorOneLocationPoint,
OrientationAxes = new AxesFixedOffset(sensorAxesOne, rotationOne),
};
// Set the identifier for the sensor in the CZML document.
m_aircraftSensorOne.Extensions.Add(new IdentifierExtension("AircraftSensorOne"));
m_aircraftSensorOne.Extensions.Add(new CesiumPositionExtension
{
InterpolationAlgorithm = CesiumInterpolationAlgorithm.Hermite
});
// Define the sensor geometry.
m_aircraftSensorOne.Extensions.Add(new FieldOfViewExtension(sensorCone));
// Configure graphical display of the sensor.
m_aircraftSensorOne.Extensions.Add(new FieldOfViewGraphicsExtension(new SensorFieldOfViewGraphics
{
// Configure the outline of the projection onto the earth.
EllipsoidSurfaceMaterial = new SolidColorMaterialGraphics(Color.White),
IntersectionWidth = 2.0,
LateralSurfaceMaterial = new GridMaterialGraphics
{
Color = Color.FromArgb(171, Color.Blue),
},
}));
// Create sensor pointing to the "side".
// Position sensor underneath the wing.
var sensorTwoLocationPoint = new PointFixedOffset(m_aircraft.ReferenceFrame, new Cartesian(-3.0, -8.0, 0.0));
var sensorAxesTwo = new AxesAlignedConstrained(m_aircraft.OrientationAxes.GetVectorElement(CartesianElement.Z), AxisIndicator.Third,
m_aircraft.OrientationAxes.GetVectorElement(CartesianElement.Y), AxisIndicator.Second);
// This rotation points the z-axis of the volume back along the x-axis of the ellipsoid.
var rotationTwo = new UnitQuaternion(new ElementaryRotation(AxisIndicator.First, Constants.HalfPi / 2));
m_aircraftSensorTwo = new Platform
{
LocationPoint = sensorTwoLocationPoint,
OrientationAxes = new AxesFixedOffset(sensorAxesTwo, rotationTwo),
};
// Set the identifier for the sensor in the CZML document.
m_aircraftSensorTwo.Extensions.Add(new IdentifierExtension("AircraftSensorTwo"));
m_aircraftSensorTwo.Extensions.Add(new CesiumPositionExtension
{
InterpolationAlgorithm = CesiumInterpolationAlgorithm.Hermite
});
// Define the sensor geometry.
m_aircraftSensorTwo.Extensions.Add(new FieldOfViewExtension(sensorCone));
// Configure graphical display of the sensor.
m_aircraftSensorTwo.Extensions.Add(new FieldOfViewGraphicsExtension(new SensorFieldOfViewGraphics
{
// Configure the outline of the projection onto the earth.
EllipsoidSurfaceMaterial = new SolidColorMaterialGraphics(Color.White),
IntersectionWidth = 2.0,
LateralSurfaceMaterial = new GridMaterialGraphics
{
Color = Color.FromArgb(171, Color.Red),
},
}));
// Create an access link between the aircraft and the observer position
// on Mount St. Helens, using the same azimuth elevation mask to constrain access.
m_aircraftAzimuthElevationMaskLink = new LinkInstantaneous(m_maskPlatform, m_aircraft);
// Set the identifier for the link in the CZML document.
m_aircraftAzimuthElevationMaskLink.Extensions.Add(new IdentifierExtension("AircraftMountStHelensAccess"));
// Constrain access using the azimuth-elevation mask.
var query = new AzimuthElevationMaskConstraint(m_aircraftAzimuthElevationMaskLink, LinkRole.Transmitter);
// Configure graphical display of the access link.
m_aircraftAzimuthElevationMaskLink.Extensions.Add(new LinkGraphicsExtension(new LinkGraphics
{
// Show the access link only when access is satisfied.
Show = new AccessQueryCesiumProperty <bool>(query, true, false, false),
Material = new SolidColorMaterialGraphics(Color.Yellow),
}));
}
