private void TestRV(OrbitData od, GameObject planet, GameObject star)
{
GameObject testPlanet = TestSetupUtils.CreatePlanetInHyper(star, 1f);
testPlanet.name = "TestPlanet";
OrbitHyper testHyper = testPlanet.GetComponent <OrbitHyper>();
testHyper.InitFromOrbitData(od);
planet.name = "Planet";
// Awkward but cannot add a new object to GE when it is stopped, so re-add all three
GravityEngine ge = GravityEngine.Instance();
ge.Clear();
ge.AddBody(star);
ge.AddBody(planet);
ge.AddBody(testPlanet);
ge.Setup();
ge.LogDump();
Vector3 r_od = ge.GetPhysicsPosition(testPlanet.GetComponent <NBody>());
Vector3 v_od = ge.GetVelocity(testPlanet);
Vector3 r_i = ge.GetPhysicsPosition(planet.GetComponent <NBody>());
Vector3 v_i = ge.GetVelocity(planet);
Debug.Log(" r_i=" + r_i + " r_od=" + r_od + " delta=" + Vector3.Distance(r_i, r_od));
Debug.Log(" v_i=" + v_i + " v_od=" + v_od + " delta=" + Vector3.Distance(v_i, v_od));
Assert.IsTrue(FloatEqual(Vector3.Distance(r_i, r_od), 0f, 5E-2));
Assert.IsTrue(FloatEqual(Vector3.Distance(v_i, v_od), 0f, 5E-2));
}
private void TestRV(OrbitData od, GameObject planet, NBody starNbody, float orbitRadius)
{
GameObject testPlanet = TestSetupUtils.CreatePlanetInOrbitUniversal(starNbody, 1f, orbitRadius);
OrbitUniversal orbitU = testPlanet.GetComponent <OrbitUniversal>();
// Run init explicitly to update transform details
orbitU.InitFromOrbitData(od, 0);
// Awkward but previously could not add a new object to GE when it is stopped, so re-add all three
// Leave as is, since it works!
GravityEngine ge = GravityEngine.Instance();
ge.Clear();
ge.AddBody(starNbody.gameObject);
ge.AddBody(planet);
ge.AddBody(testPlanet);
ge.Setup();
ge.LogDump();
Vector3 r_od = ge.GetPhysicsPosition(testPlanet.GetComponent <NBody>());
Vector3 v_od = ge.GetVelocity(testPlanet);
Vector3 r_i = ge.GetPhysicsPosition(planet.GetComponent <NBody>());
Vector3 v_i = ge.GetVelocity(planet);
Debug.Log(" r_i=" + r_i + " r_od=" + r_od + " delta=" + Vector3.Distance(r_i, r_od));
Debug.Log(" v_i=" + v_i + " v_od=" + v_od + " delta=" + Vector3.Distance(v_i, v_od));
Assert.IsTrue(GEUnit.FloatEqual(Vector3.Distance(r_i, r_od), 0f, 1E-2));
Assert.IsTrue(GEUnit.FloatEqual(Vector3.Distance(v_i, v_od), 0f, 1E-2));
}
private void TestRV(OrbitData od, GameObject planet, GameObject star, float orbitRadius)
{
GameObject testPlanet = TestSetupUtils.CreatePlanetInOrbit(star, 1f, orbitRadius);
OrbitEllipse testEllipse = testPlanet.GetComponent <OrbitEllipse>();
// Run init explicitly to update transform details
testEllipse.InitFromOrbitData(od);
// Awkward but cannot add a new object to GE when it is stopped, so re-add all three
GravityEngine ge = GravityEngine.Instance();
ge.Clear();
ge.AddBody(star);
ge.AddBody(planet);
ge.AddBody(testPlanet);
ge.Setup();
ge.LogDump();
Vector3 r_od = ge.GetPhysicsPosition(testPlanet.GetComponent <NBody>());
Vector3 v_od = ge.GetVelocity(testPlanet);
Vector3 r_i = ge.GetPhysicsPosition(planet.GetComponent <NBody>());
Vector3 v_i = ge.GetVelocity(planet);
Debug.Log(" r_i=" + r_i + " r_od=" + r_od + " delta=" + Vector3.Distance(r_i, r_od));
Debug.Log(" v_i=" + v_i + " v_od=" + v_od + " delta=" + Vector3.Distance(v_i, v_od));
Assert.IsTrue(FloatEqual(Vector3.Distance(r_i, r_od), 0f, 1E-2));
Assert.IsTrue(FloatEqual(Vector3.Distance(v_i, v_od), 0f, 1E-2));
}
public string DumpAll(NBody[] gameNBodies, GravityEngine ge)
{
System.Text.StringBuilder sb = new System.Text.StringBuilder();
sb.Append("Massive Bodies:\n");
for (int i = 0; i < numBodies; i++)
{
Vector3 vel = ge.GetVelocity(gameNBodies[i]);
int engineIndex = gameNBodies[i].engineRef.index;
sb.Append(string.Format(" n={0} {1} m={2} r={3} {4} {5} v={6} {7} {8} info={9} engineRef.index={10} extAcc={11}\n",
i, gameNBodies[i].name,
m[i], r[i, 0], r[i, 1], r[i, 2],
vel.x, vel.y, vel.z, info[i], engineIndex, integrator.GetExternalAccelForIndex(engineIndex)
));
}
// Title printed by MBE
if (masslessEngine != null)
{
sb.Append(masslessEngine.DumpString());
}
sb.Append("Fixed Bodies:\n");
for (int i = 0; i < fixedBodies.Count; i++)
{
int fb_index = fixedBodies[i].nbody.engineRef.index;
sb.Append(string.Format(" n={0} {1} kepler_depth={2}\n",
i,
gameNBodies[fb_index].name,
fixedBodies[i].kepler_depth));
// add extra info if OrbitU or KeplerSeq
sb.Append(fixedBodies[i].nbody.engineRef.fixedBody.fixedOrbit.DumpInfo());
}
sb.Append(" fixedBodiesInIntegrator=" + fixedBodiesInIntegrator);
// Any pending maneuvers - TODO
// sb.Append(maneuverMgr.DumpAll());
return(sb.ToString());
}
/// <summary>
/// Execute the maneuver. Called automatically by Gravity Engine for maneuvers that
/// have been added to the GE via AddManeuver().
///
/// Unusual to call this method directly.
/// </summary>
/// <param name="ge"></param>
public void Execute(GravityEngine ge)
{
Vector3 vel = ge.GetVelocity(nbody);
switch (mtype)
{
case Mtype.vector:
vel += velChange;
break;
case Mtype.scalar:
// scalar: adjust existing velocity by dV
Vector3 change = Vector3.Normalize(vel) * dV;
vel += change;
break;
case Mtype.circularize:
// find velocity vector perpendicular to r for circular orbit
// Since we could be mid-integration need to get exact position from GE
double[] r_ship = new double[3];
double[] v_ship = new double[3];
ge.GetPositionVelocityScaled(nbody, ref r_ship, ref v_ship);
double[] r_center = new double[3];
double[] v_center = new double[3];
ge.GetPositionVelocityScaled(centerBody, ref r_center, ref v_center);
Vector3 pos_ship = new Vector3((float)r_ship[0], (float)r_ship[1], (float)r_ship[2]);
Vector3 vel_ship = new Vector3((float)v_ship[0], (float)v_ship[1], (float)v_ship[2]);
Vector3 pos_center = new Vector3((float)r_center[0], (float)r_center[1], (float)r_center[2]);
Vector3 r = pos_ship - pos_center;
// to get axis of orbit, can take v x r
Vector3 axis = Vector3.Normalize(Vector3.Cross(vel_ship, pos_ship));
// vis visa for circular orbit
float mu = nbody.mass * ge.massScale;
float v_mag = Mathf.Sqrt(mu / Vector3.Magnitude(r));
// positive v is counter-clockwise
Vector3 v_dir = Vector3.Normalize(Vector3.Cross(axis, r));
Vector3 v_circular = v_mag * v_dir;
ge.SetVelocity(nbody, v_circular);
break;
}
#pragma warning disable 162 // disable unreachable code warning
if (GravityEngine.DEBUG)
{
Debug.Log("Applied manuever: " + LogString() + " engineRef.index=" + nbody.engineRef.index +
" engineRef.bodyType=" + nbody.engineRef.bodyType + " timeError=" + (worldTime - ge.GetPhysicalTime()));
Debug.Log("r= " + Vector3.Magnitude(nbody.transform.position));
}
#pragma warning restore 162 // enable unreachable code warning
ge.SetVelocity(nbody, vel);
}
// If there is no init delegate use the initial particle position (scaled to physics space) and the
// initial particle velocity to seed the particle physics data.
private void NoInitDelegateSetup(int fromP, int toP)
{
float scale = gravityEngine.physToWorldFactor;
Vector3 sourceVelocity = Vector3.zero;
if (addNBodyVelocity && nbodySource != null)
{
sourceVelocity = gravityEngine.GetVelocity(nbodySource);
}
sourceVelocity += initialVelocity;
for (int i = fromP; i < toP; i++)
{
// particles are in world space - just use their position
r[i, 0] = (particles[i].position.x) / scale;
r[i, 1] = (particles[i].position.y) / scale;
r[i, 2] = (particles[i].position.z) / scale;
v[i, 0] = sourceVelocity.x + particles[i].velocity.x;
v[i, 1] = sourceVelocity.y + particles[i].velocity.y;
v[i, 2] = sourceVelocity.z + particles[i].velocity.z;
inactive[i] = false;
particles[i].velocity = Vector3.zero;
}
}
/// <summary>
/// Computes the transfer and updates all the ghost bodies.
/// </summary>
/// <returns></returns>
private void ComputeTransfer()
{
double timeNow = ge.GetPhysicalTimeDouble();
// First using the transfer time, move the ghost Moon to position at SOI arrival.
// Call evolve via LockAtTime on the ghostMoon to move it. Set position based on this.
double t_flight = tflightFactor * timeHohmann;
double timeatSoi = timeNow + t_flight;
ghostMoonOrbit[MOON_SOI_ENTER].LockAtTime(timeatSoi);
// Determine the moon phase angle
double moonPhase = ghostMoonSoiEnterOrbitPredictor.GetOrbitUniversal().phase;
// Place the TLI ship at the user-requested angle wrt planet-moon line
// Put ghost ship in same orbit geometry as the moon, assuming it is circular. Then
// can use same phase value.
// (Ship needs to reach this departure point, it may not even be on the ship orbit
// in general).
ghostShipOrbit[TLI].phase = shipTLIAngleDeg + (moonPhase + 180f);
ghostShipOrbit[TLI].inclination = ghostMoonOrbit[MOON_SOI_ENTER].inclination;
ghostShipOrbit[TLI].omega_lc = ghostMoonOrbit[MOON_SOI_ENTER].omega_lc;
ghostShipOrbit[TLI].omega_uc = ghostMoonOrbit[MOON_SOI_ENTER].omega_uc;
ghostShipOrbit[TLI].p_inspector = shipOrbit.p;
ghostShipOrbit[TLI].Init();
ghostShipOrbit[TLI].LockAtTime(0);
// Place the SOI enter ship at the user-requested angle in an SOI orbit. Lock at time 0 so the phase
// is held per the user input.
ghostShipOrbit[ENTER_SOI].phase = soiAngleDeg + moonPhase;
ghostShipOrbit[ENTER_SOI].inclination = soiInclination + shipOrbit.inclination;
ghostShipOrbit[ENTER_SOI].omega_lc = ghostMoonOrbit[MOON_SOI_ENTER].omega_lc;
ghostShipOrbit[ENTER_SOI].omega_uc = ghostMoonOrbit[MOON_SOI_ENTER].omega_uc;
ghostShipOrbit[ENTER_SOI].Init();
ghostShipOrbit[ENTER_SOI].LockAtTime(0);
// Find the line to the ENTER_SOI position. Ship departs from that line continued through planet
// at the shipRadius distance (assumes circular ship orbit)
// TODO: Handle planet not at (0,0,0)
Vector3d soiEntryPos = ge.GetPositionDoubleV3(ghostShip[ENTER_SOI]);
Vector3d planetPos = ge.GetPositionDoubleV3(planet);
Vector3d departurePoint = ge.GetPositionDoubleV3(ghostShip[TLI]);
// Use Lambert to find the departure velocity to get from departure to soiEntry
// Since we need 180 degrees from departure to arrival, use LambertBattin
lambertB = new LambertBattin(ghostShip[TO_MOON], planet, departurePoint, soiEntryPos, shipOrbit.GetAxis());
// apply any time of flight change
bool reverse = !shortPath;
const bool df = false;
const int nrev = 0;
int error = lambertB.ComputeXfer(reverse, df, nrev, t_flight);
if (error != 0)
{
Debug.LogWarning("Lambert failed to find solution. error=" + error);
return;
}
// Check Lambert is going in the correct direction
//Vector3 shipOrbitAxis = Vector3.Cross(ge.GetPhysicsPosition(spaceship), ge.GetVelocity(spaceship) ).normalized;
//Vector3 tliOrbitAxis = Vector3.Cross(departurePoint.ToVector3(), lambertB.GetTransferVelocity().ToVector3()).normalized;
Vector3 shipOrbitAxis = Vector3.Cross(ge.GetVelocity(spaceship), ge.GetPhysicsPosition(spaceship)).normalized;
Vector3 tliOrbitAxis = Vector3.Cross(lambertB.GetTransferVelocity().ToVector3(), departurePoint.ToVector3()).normalized;
if (Vector3.Dot(shipOrbitAxis, tliOrbitAxis) < 0)
{
error = lambertB.ComputeXfer(!reverse, df, nrev, t_flight);
if (error != 0)
{
Debug.LogWarning("Lambert failed to find solution for reverse path. error=" + error);
return;
}
}
Debug.LogFormat("tli_vel={0}", lambertB.GetTransferVelocity());
ghostShipOrbit[TO_MOON].InitFromRVT(departurePoint, lambertB.GetTransferVelocity(), timeNow, planet, false);
// Set velocity for orbit around moon. Will be updated every frame
ghostShipOrbit[SOI_HYPER].InitFromRVT(soiEntryPos, lambertB.GetFinalVelocity(), timeNow, ghostMoon[MOON_SOI_ENTER], false);
// Find the exit point of the hyperbola in the SOI
OrbitUtils.OrbitElements oe = OrbitUtils.RVtoCOE(soiEntryPos, lambertB.GetFinalVelocity(), ghostMoon[MOON_SOI_ENTER], false);
Vector3d soiExitR = new Vector3d();
Vector3d soiExitV = new Vector3d();
OrbitUtils.COEtoRVMirror(oe, ghostMoon[MOON_SOI_ENTER], ref soiExitR, ref soiExitV, false);
// Find time to go around the moon. TOF requires relative positions!!
Vector3d ghostSoiEnterPos = ge.GetPositionDoubleV3(ghostMoon[MOON_SOI_ENTER]);
Vector3d soiEnterRelative = soiEntryPos - ghostSoiEnterPos;
Vector3d soiExitRelative = soiExitR - ghostSoiEnterPos;
Vector3d soiExitVelRelative = soiExitV - ge.GetVelocityDoubleV3(ghostMoon[MOON_SOI_ENTER]);
double hyperTOF = ghostShipOrbit[SOI_HYPER].TimeOfFlight(soiEnterRelative, soiExitRelative);
// Position the ghost moon for SOI exit (timeAtSoi includes timeNow)
t_soiExit = timeatSoi + hyperTOF;
ghostMoonOrbit[MOON_SOI_EXIT].LockAtTime(t_soiExit);
// Set position and vel for exit ship, so exit orbit predictor can run.
Vector3d ghostMoonSoiExitPos = ge.GetPositionDoubleV3(ghostMoon[MOON_SOI_EXIT]);
Vector3d ghostMoonSoiExitVel = ge.GetVelocityDoubleV3(ghostMoon[MOON_SOI_EXIT]);
ghostShipOrbit[EXIT_SOI].InitFromRVT(soiExitRelative + ghostMoonSoiExitPos,
soiExitVelRelative + ghostMoonSoiExitVel,
timeNow, planet, false);
}
/// <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);
}
// Update is called once per frame
void Update()
{
Vector3 v = ge.GetVelocity(nbody.gameObject);
transform.rotation = Quaternion.FromToRotation(axis.normalized, v.normalized);
}
