/// <summary>
/// Sets the true anomaly and updates all other anomalies.
/// </summary>
/// <param name="t">The t.</param>
public void SetTrueAnomaly(double t)
{
if (!IsValidOrbit)
{
return;
}
t %= Mathd.PI_2;
if (Eccentricity < 1)
{
if (t < 0)
{
t += Mathd.PI_2;
}
EccentricAnomaly = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(t, Eccentricity);
MeanAnomaly = EccentricAnomaly - Eccentricity * Math.Sin(EccentricAnomaly);
}
else
{
EccentricAnomaly = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(t, Eccentricity);
MeanAnomaly = Math.Sinh(EccentricAnomaly) * Eccentricity - EccentricAnomaly;
}
SetPositionByCurrentAnomaly();
SetVelocityByCurrentAnomaly();
}
public void SetTrueAnomaly(double t)
{
if (!isValidOrbit)
{
return;
}
t %= Mathd.PI_2;
if (eccentricity < 1)
{
if (t < 0)
{
t += Mathd.PI_2;
}
eccentricAnomaly = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(t, eccentricity);
meanAnomaly = eccentricAnomaly - eccentricity * System.Math.Sin(eccentricAnomaly);
}
else
{
eccentricAnomaly = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(t, eccentricity);
meanAnomaly = System.Math.Sinh(eccentricAnomaly) * eccentricity - eccentricAnomaly;
}
SetPositionByCurrentAnomaly();
SetVelocityByCurrentAnomaly();
}
/// <summary>
/// Gets the central position at true anomaly.
/// </summary>
/// <param name="trueAnomaly">The true anomaly.</param>
/// <returns>Position relative to orbit center.</returns>
/// <remarks>
/// Note: central position is not same as focal position.
/// </remarks>
public Vector3d GetCentralPositionAtTrueAnomaly(double trueAnomaly)
{
var ecc = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(trueAnomaly, Eccentricity);
return(GetCentralPositionAtEccentricAnomaly(ecc));
}
/// <summary>
/// Calculates the full state of orbit from current body position, attractor position, attractor mass, velocity, and gravConstant.
/// </summary>
public void CalculateNewOrbitData()
{
IsDirty = false;
var MG = AttractorMass * GravitationalConstant;
AttractorDistance = Position.magnitude;
var angularMomentumVector = CelestialBodyUtils.CrossProduct(Position, Velocity);
OrbitNormal = angularMomentumVector.normalized;
Vector3d eccVector;
// Check if zero lenght.
if (OrbitNormal.sqrMagnitude < 0.9 || OrbitNormal.sqrMagnitude > 1.1)
{
OrbitNormal = CelestialBodyUtils.CrossProduct(Position, EclipticUp).normalized;
eccVector = new Vector3d();
}
else
{
eccVector = CelestialBodyUtils.CrossProduct(Velocity, angularMomentumVector) / MG - Position / AttractorDistance;
}
OrbitNormalDotEclipticNormal = CelestialBodyUtils.DotProduct(OrbitNormal, EclipticNormal);
FocalParameter = angularMomentumVector.sqrMagnitude / MG;
Eccentricity = eccVector.magnitude;
EnergyTotal = Velocity.sqrMagnitude - 2 * MG / AttractorDistance;
SemiMinorAxisBasis = CelestialBodyUtils.CrossProduct(angularMomentumVector, eccVector).normalized;
if (SemiMinorAxisBasis.sqrMagnitude < 0.5)
{
SemiMinorAxisBasis = CelestialBodyUtils.CrossProduct(OrbitNormal, Position).normalized;
}
SemiMajorAxisBasis = CelestialBodyUtils.CrossProduct(OrbitNormal, SemiMinorAxisBasis).normalized;
Inclination = Vector3d.Angle(OrbitNormal, EclipticNormal) * Mathd.Deg2Rad;
if (Eccentricity < 1)
{
OrbitCompressionRatio = 1 - Eccentricity * Eccentricity;
SemiMajorAxis = FocalParameter / OrbitCompressionRatio;
SemiMinorAxis = SemiMajorAxis * Math.Sqrt(OrbitCompressionRatio);
CenterPoint = -SemiMajorAxis * eccVector;
Period = Mathd.PI_2 * Mathd.Sqrt(Mathd.Pow(SemiMajorAxis, 3) / MG);
Apoapsis = CenterPoint + SemiMajorAxisBasis * SemiMajorAxis;
Periapsis = CenterPoint - SemiMajorAxisBasis * SemiMajorAxis;
PeriapsisDistance = Periapsis.magnitude;
ApoapsisDistance = Apoapsis.magnitude;
TrueAnomaly = Vector3d.Angle(Position, -SemiMajorAxisBasis) * Mathd.Deg2Rad;
if (CelestialBodyUtils.DotProduct(CelestialBodyUtils.CrossProduct(Position, SemiMajorAxisBasis), OrbitNormal) < 0)
{
TrueAnomaly = Mathd.PI_2 - TrueAnomaly;
}
EccentricAnomaly = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(TrueAnomaly, Eccentricity);
MeanAnomaly = EccentricAnomaly - Eccentricity * Math.Sin(EccentricAnomaly);
}
else
{
OrbitCompressionRatio = Eccentricity * Eccentricity - 1;
SemiMajorAxis = FocalParameter / OrbitCompressionRatio;
SemiMinorAxis = SemiMajorAxis * Math.Sqrt(OrbitCompressionRatio);
CenterPoint = SemiMajorAxis * eccVector;
Period = double.PositiveInfinity;
Apoapsis = new Vector3d(double.PositiveInfinity, double.PositiveInfinity, double.PositiveInfinity);
Periapsis = CenterPoint + SemiMajorAxisBasis * (SemiMajorAxis);
PeriapsisDistance = Periapsis.magnitude;
ApoapsisDistance = double.PositiveInfinity;
TrueAnomaly = Vector3d.Angle(Position, eccVector) * Mathd.Deg2Rad;
if (CelestialBodyUtils.DotProduct(CelestialBodyUtils.CrossProduct(Position, SemiMajorAxisBasis), OrbitNormal) < 0)
{
TrueAnomaly = -TrueAnomaly;
}
EccentricAnomaly = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(TrueAnomaly, Eccentricity);
MeanAnomaly = Math.Sinh(EccentricAnomaly) * Eccentricity - EccentricAnomaly;
}
}
public void CalculateNewOrbitData()
{
isDirty = false;
var MG = attractorMass * gravConst;
attractorDistance = position.magnitude;
var angularMomentumVector = CelestialBodyUtils.CrossProduct(position, velocity);
orbitNormal = angularMomentumVector.normalized;
Vector3d eccVector;
if (orbitNormal.sqrMagnitude < 0.9 || orbitNormal.sqrMagnitude > 1.1) //check if zero lenght
{
orbitNormal = CelestialBodyUtils.CrossProduct(position, eclipticUp).normalized;
eccVector = new Vector3d();
}
else
{
eccVector = CelestialBodyUtils.CrossProduct(velocity, angularMomentumVector) / MG - position / attractorDistance;
}
orbitNormalDotEclipticNormal = CelestialBodyUtils.DotProduct(orbitNormal, eclipticNormal);
focalParameter = angularMomentumVector.sqrMagnitude / MG;
eccentricity = eccVector.magnitude;
//if (debug) {
// string format = "0.0000000000";
// Debug.Log(
// "ECC: " + eccVector.ToString(format) + " LEN: " + eccVector.magnitude.ToString(format) + "\n" +
// "POS: " + position.ToString(format) + " LEN: " + position.magnitude.ToString(format) + "\n" +
// "POSNORM: " + ( position / attractorDistance ).ToString(format) + " LEN: " + ( position / attractorDistance ).magnitude.ToString(format) + "\n" +
// "VEL: " + velocity.ToString(format) + " LEN: " + velocity.magnitude.ToString(format) + "\n" +
// "POScrossVEL: " + angularMomentumVector.ToString(format) + " LEN: " + angularMomentumVector.magnitude.ToString(format) + "\n"
// );
//}
energyTotal = velocity.sqrMagnitude - 2 * MG / attractorDistance;
semiMinorAxisBasis = CelestialBodyUtils.CrossProduct(angularMomentumVector, eccVector).normalized;
if (semiMinorAxisBasis.sqrMagnitude < 0.5)
{
semiMinorAxisBasis = CelestialBodyUtils.CrossProduct(orbitNormal, position).normalized;
}
semiMajorAxisBasis = CelestialBodyUtils.CrossProduct(orbitNormal, semiMinorAxisBasis).normalized;
inclination = Vector3d.Angle(orbitNormal, eclipticNormal) * Mathd.Deg2Rad;
if (eccentricity < 1)
{
orbitCompressionRatio = 1 - eccentricity * eccentricity;
semiMajorAxis = focalParameter / orbitCompressionRatio;
semiMinorAxis = semiMajorAxis * System.Math.Sqrt(orbitCompressionRatio);
centerPoint = -semiMajorAxis * eccVector;
period = Mathd.PI_2 * Mathd.Sqrt(Mathd.Pow(semiMajorAxis, 3) / MG);
apoapsis = centerPoint + semiMajorAxisBasis * semiMajorAxis;
periapsis = centerPoint - semiMajorAxisBasis * semiMajorAxis;
periapsisDistance = periapsis.magnitude;
apoapsisDistance = apoapsis.magnitude;
trueAnomaly = Vector3d.Angle(position, -semiMajorAxisBasis) * Mathd.Deg2Rad;
if (CelestialBodyUtils.DotProduct(CelestialBodyUtils.CrossProduct(position, semiMajorAxisBasis), orbitNormal) < 0)
{
trueAnomaly = Mathd.PI_2 - trueAnomaly;
}
eccentricAnomaly = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(trueAnomaly, eccentricity);
meanAnomaly = eccentricAnomaly - eccentricity * System.Math.Sin(eccentricAnomaly);
}
else
{
orbitCompressionRatio = eccentricity * eccentricity - 1;
semiMajorAxis = focalParameter / orbitCompressionRatio;
semiMinorAxis = semiMajorAxis * System.Math.Sqrt(orbitCompressionRatio);
centerPoint = semiMajorAxis * eccVector;
period = double.PositiveInfinity;
apoapsis = new Vector3d(double.PositiveInfinity, double.PositiveInfinity, double.PositiveInfinity);
periapsis = centerPoint + semiMajorAxisBasis * (semiMajorAxis);
periapsisDistance = periapsis.magnitude;
apoapsisDistance = double.PositiveInfinity;
trueAnomaly = Vector3d.Angle(position, eccVector) * Mathd.Deg2Rad;
if (CelestialBodyUtils.DotProduct(CelestialBodyUtils.CrossProduct(position, semiMajorAxisBasis), orbitNormal) < 0)
{
trueAnomaly = -trueAnomaly;
}
eccentricAnomaly = CelestialBodyUtils.ConvertTrueToEccentricAnomaly(trueAnomaly, eccentricity);
meanAnomaly = System.Math.Sinh(eccentricAnomaly) * eccentricity - eccentricAnomaly;
}
}
