private void DoTestForPhase(double fromPhase, double toPhase)
{
const float mass = 1000f;
const bool reverse = false;
GameObject star = TestSetupUtils.CreateNBody(mass, new Vector3(0, 0, 0));
NBody starNbody = star.GetComponent <NBody>();
float orbitRadius = 20f;
GameObject planet = TestSetupUtils.CreatePlanetInOrbitUniversal(starNbody, 0f, orbitRadius);
OrbitUniversal orbitU = planet.GetComponent <OrbitUniversal>();
orbitU.phase = fromPhase;
orbitU.SetMajorAxisInspector(orbitRadius);
orbitRadius = 30.0f;
GameObject planet2 = TestSetupUtils.CreatePlanetInOrbitUniversal(starNbody, 0f, orbitRadius);
OrbitUniversal orbitU2 = planet2.GetComponent <OrbitUniversal>();
orbitU2.phase = toPhase;
orbitU2.SetMajorAxisInspector(orbitRadius);
GravityEngine.Instance().UnitTestAwake();
GravityEngine.Instance().AddBody(star);
GravityEngine.Instance().AddBody(planet);
GravityEngine.Instance().AddBody(planet2);
GravityEngine.Instance().Setup();
Debug.Log("Find transfers");
OrbitData fromOrbit = new OrbitData(orbitU);
OrbitData toOrbit = new OrbitData(orbitU2);
LambertUniversal lambertU = new LambertUniversal(fromOrbit, toOrbit, true);
Assert.AreNotEqual(lambertU, null);
double time = 0.8f * lambertU.GetTMin();
lambertU.ComputeXfer(reverse, false, 0, time);
LambertBattin lambertB = new LambertBattin(fromOrbit, toOrbit);
int error = lambertB.ComputeXfer(reverse, false, 0, time);
Assert.AreEqual(error, 0);
Assert.AreNotEqual(lambertB, null);
Assert.AreNotEqual(lambertB.GetTransferVelocity(), null);
Debug.LogFormat("initial velocity {0} vs {1}", lambertU.GetTransferVelocity(), lambertB.GetTransferVelocity());
Debug.LogFormat("initial velocity mag {0} vs {1}",
lambertU.GetTransferVelocity().magnitude, lambertB.GetTransferVelocity().magnitude);
Debug.LogFormat("final velocity {0} vs {1}", lambertU.GetFinalVelocity(), lambertB.GetFinalVelocity());
Debug.LogFormat("final velocity mag {0} vs {1}",
lambertU.GetFinalVelocity().magnitude, lambertB.GetFinalVelocity().magnitude);
// best can do for 180 degree case is E-2 accuracy on the magnitude. Not sure why...seems too big
Assert.IsTrue(GEUnit.DoubleEqual(lambertU.GetTransferVelocity().magnitude,
lambertB.GetTransferVelocity().magnitude,
1E-2));
}
/// <summary>
/// Set up a KeplerSeqeunce to do the three phases of the transfer as Kepler mode conics.
///
/// Leave the existing ship orbit as the first
/// </summary>
/// <param name="transferTime"></param>
private void TransferOnRails(double transferTime, Vector3 shipPos, Vector3 shipVel, float moonOmega)
{
// the ship needs to have a KeplerSequence
KeplerSequence kseq = spaceship.GetComponent <KeplerSequence>();
if (kseq == null)
{
Debug.LogError("Could not find a KeplerSequence on " + spaceship.name);
return;
}
float moonPhaseDeg = moonOmega * (float)transferTime * Mathf.Rad2Deg;
Quaternion moonPhaseRot = Quaternion.AngleAxis(moonPhaseDeg, Vector3.forward);
// Ellipse 1: shipPos/shipvel already phased by the caller.
double t = ge.GetPhysicalTime();
KeplerSequence.ElementStarted noCallback = null;
kseq.AppendElementRVT(new Vector3d(shipPos), new Vector3d(shipVel), t, false, spaceship, planet, noCallback);
// Hyperbola: start at t + transferTime
// have targetPoint and final velocity from LambertTransfer. Need to make these wrt moon at this time
// targetPoint is w.r.t current moon position, but need to rotate around SOI by amount moon will shift
// as ship transits to moon
Vector3 targetPos = targetPoint.ToVector3();
Vector3 moonPosAtSoi = moonPhaseRot * ge.GetPhysicsPosition(moonBody);
Vector3 moonVelAtSoi = moonPhaseRot * ge.GetVelocity(moonBody);
// get the relative positions (i.e. as if moon at the origin with v=0)
Vector3 adjustedTarget = moonPhaseRot * targetPos - moonPosAtSoi;
Vector3 adjustedVel = moonPhaseRot * lambertU.GetFinalVelocity() - moonVelAtSoi;
// Create moon hyperbola at the moon position after flight to moon. This means the init cannot make reference
// to the CURRENT moon position.
Vector3d soiEnterR = new Vector3d(adjustedTarget);
Vector3d soiEnterV = new Vector3d(adjustedVel);
OrbitUniversal hyperOrbit = kseq.AppendElementRVT(soiEnterR,
soiEnterV,
t + transferTime,
true,
spaceship,
moonBody,
EnterMoonSoi);
// Find the hyperbola exit SOI position/vel
OrbitUtils.OrbitElements oe = OrbitUtils.RVtoCOE(soiEnterR, soiEnterV, moonBody, true);
Vector3d soiExitR = new Vector3d();
Vector3d soiExitV = new Vector3d();
Debug.Log("oe=" + oe);
// Gives position and velocity in relative position
OrbitUtils.COEtoRVMirror(oe, moonBody, ref soiExitR, ref soiExitV, true);
// Determine hyperbola transit time to the soiExit position
double hyperTOF = hyperOrbit.TimeOfFlight(soiEnterR, soiExitR);
//Debug.LogFormat("Hyper TOF={0} r0={1} r1={2} p={3}", hyperTOF, adjustedTarget, soiExitR,
// hyperOrbit.p);
// Ellipse 2:
// Adjust phase to allow for moon travel during hyperbola transit
// Need to set position and vel relative to the planet using position relative to moon at 0
moonPhaseDeg = moonOmega * (float)hyperTOF * Mathf.Rad2Deg;
Quaternion moonHyperRot = Quaternion.AngleAxis(moonPhaseDeg, Vector3.forward);
Vector3 moonAtExit = moonHyperRot * moonPosAtSoi;
Vector3 moonVelAtExit = moonHyperRot * moonVelAtSoi;
Vector3 soiExitwrtPlanet = soiExitR.ToVector3() + moonAtExit;
// soiexitV is relative to moon at (0,0,0) BUT frame of hyperbola does not rotate
Vector3 soiExitVelwrtPlanet = moonHyperRot * soiExitV.ToVector3() + moonVelAtExit;
Debug.LogFormat("Ellipse2: soiExitV={0} moonV={1} net={2}", soiExitV, moonVelAtExit, soiExitVelwrtPlanet);
kseq.AppendElementRVT(new Vector3d(soiExitwrtPlanet),
new Vector3d(soiExitVelwrtPlanet),
t + transferTime + hyperTOF,
true,
spaceship,
planet,
ExitMoonSoi);
running = true;
}
/// <summary>
/// Computes the transfer with the moon on the +X axis without accounting for the moon motion during
/// transit. (That is accounted for in the ExecuteTransfer routine).
///
/// This allows a co-rotating visualization of the orbit.
/// </summary>
/// <returns></returns>
private Vector3 ComputeTransfer()
{
OrbitData shipOrbit = new OrbitData();
shipOrbit.SetOrbitForVelocity(spaceship, planet);
// compute the min energy path (this will be in the short path direction)
lambertU = new LambertUniversal(shipOrbit, startPoint, targetPoint, shortPath);
// apply any time of flight change
double t_flight = tflightFactor * lambertU.GetTMin();
bool reverse = !shortPath;
const bool df = false;
const int nrev = 0;
int error = lambertU.ComputeXfer(reverse, df, nrev, t_flight);
if (error != 0)
{
Debug.LogWarning("Lambert failed to find solution.");
aroundMoonSegment.gameObject.SetActive(false);
return(Vector3.zero);
}
// Check Lambert is going in the correct direction
Vector3 shipOrbitAxis = Vector3.Cross(ge.GetVelocity(spaceship), ge.GetPhysicsPosition(spaceship)).normalized;
Vector3 tliOrbitAxis = Vector3.Cross(lambertU.GetTransferVelocity(), startPoint.ToVector3());
if (Vector3.Dot(shipOrbitAxis, tliOrbitAxis) < 0)
{
error = lambertU.ComputeXfer(!reverse, df, nrev, t_flight);
if (error != 0)
{
Debug.LogWarning("Lambert failed to find solution for reverse path. error=" + error);
return(Vector3.zero);
}
}
Vector3 tliVelocity = lambertU.GetTransferVelocity();
toMoonOrbit.SetVelocity(tliVelocity);
toMoonSegment.SetVelocity(tliVelocity);
aroundMoonSegment.gameObject.SetActive(true);
// Set velocity for orbit around moon
Vector3 soiEnterVel = lambertU.GetFinalVelocity();
aroundMoonSegment.SetVelocity(soiEnterVel);
// update shipEnterSOI object
ge.UpdatePositionAndVelocity(shipEnterSOI, targetPoint.ToVector3(), soiEnterVel);
// Find the orbit around the moon. By using the mirror position we're assuming it's
// a hyperbola (since there is no course correction at SOI this is true).
// (Moon is in correct position for these calcs so can use world positions, relativePos=false)
Vector3d soiEnterV = new Vector3d(lambertU.GetFinalVelocity());
OrbitUtils.OrbitElements oe = OrbitUtils.RVtoCOE(targetPoint, soiEnterV, moonBody, false);
Vector3d soiExitR = new Vector3d();
Vector3d soiExitV = new Vector3d();
OrbitUtils.COEtoRVMirror(oe, moonBody, ref soiExitR, ref soiExitV, false);
// Set position and vel for exit ship, so exit orbit predictor can run. Moon offset/vel already added.
ge.SetPositionDoubleV3(shipExitSOI, soiExitR);
ge.SetVelocityDoubleV3(shipExitSOI, soiExitV);
aroundMoonSegment.UpdateOrbit();
return(tliVelocity);
}