/// <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; } }