public void KeplerVsTimeOfFlight()
{
// Need to make sure TOF < 1 period
const float mass = 100f;
GameObject star = TestSetupUtils.CreateNBody(mass, new Vector3(0, 0, 0));
NBody starNbody = star.GetComponent <NBody>();
const float orbitRadius = 10f;
GameObject planet = TestSetupUtils.CreatePlanetInOrbitUniversal(starNbody, 1f, orbitRadius);
OrbitUniversal orbitU = planet.GetComponent <OrbitUniversal>();
// Parabola (ecc=1.0 fails, need to investigate)
float[] ecc_values = { 0.0f, 0.1f, 0.5f, 0.9f, 1.2f, 1.5f };
foreach (float ecc in ecc_values)
{
Debug.LogFormat("======= ecc={0} =======", ecc);
orbitU.eccentricity = ecc;
orbitU.p = 10f;
orbitU.evolveMode = OrbitUniversal.EvolveMode.KEPLERS_EQN;
// Evolve to position r1
double time = 5.0;
TestSetupUtils.SetupGravityEngine(star, planet);
double[] r1 = new double[] { 0, 0, 0 };
// orbitU.PreEvolve(pscale, mscale);
// Ugh. Need to do this before call evolve, since it caches the value.
Vector3d r0_vec = GravityEngine.Instance().GetPositionDoubleV3(planet.GetComponent <NBody>());
orbitU.Evolve(time, ref r1);
Vector3d r1_vec = new Vector3d(ref r1);
// check time to r1
double time_test = orbitU.TimeOfFlight(r0_vec, r1_vec);
Debug.LogFormat("check r0={0} to r1={1} p ={2} after t={3} TOF => {4}",
r0_vec, r1_vec, orbitU.p, time, time_test);
Assert.IsTrue(GEUnit.DoubleEqual(time, time_test, 1E-4));
}
}
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));
}