/// <summary>
/// Inits the N body position and velocity based on the ellipse parameters and the
/// position and velocity of the parent.
/// </summary>
/// <param name="physicalScale">Physical scale.</param>
public void InitNBody(float physicalScale, float massScale)
{
float a_phy = a_scaled / physicalScale;
NBody nbody = GetComponent <NBody>();
// Phase is TRUE anomoly f
float f = phase * Mathf.Deg2Rad;
// Murray and Dermot
// (2.26)
// This should really be (M+m), but assume m << M
// (massScale is added in at the GE level)
float n = Mathf.Sqrt((float)(centerNbody.mass * massScale) / (a_phy * a_phy * a_phy));
// (2.36)
float denom = Mathf.Sqrt(1f - ecc * ecc);
float xdot = -1f * n * a_phy * Mathf.Sin(f) / denom;
float ydot = n * a_phy * (ecc + Mathf.Cos(f)) / denom;
// Init functions are called in the engine by SetupOneBody and calls of parent vs children/grandchildren etc.
// can be in arbitrary order. A child will need info from parent for position and velocity. Ensure parent
// has inited. Init may get called more than once.
INbodyInit centerInit = centerObject.GetComponent <INbodyInit>();
if (centerInit != null)
{
centerInit.InitNBody(physicalScale, massScale);
}
SetTransform();
Vector3 v_xy = new Vector3(xdot, ydot, 0);
Vector3 vphy = ellipse_orientation * v_xy + centerNbody.vel_scaled;
nbody.vel_scaled = vphy;
SetTransform();
}
/// <summary>
/// Inits the N body position and velocity based on the hyperbola parameters and the
/// position and velocity of the parent.
/// </summary>
/// <param name="physicalScale">Physical scale.</param>
public void InitNBody(float physicalScale, float massScale)
{
Init();
float a_phy = a_scaled / physicalScale;
if (nbody == null)
{
nbody = GetComponent <NBody>();
}
// Phase is TRUE anomoly f
float f = ThetaForR(r_initial_phy);
// Murray and Dermot (2.20)
float n = Mathf.Sqrt((float)(centerNbody.mass * massScale) / (a_phy * a_phy * a_phy));
float denom = Mathf.Sqrt(ecc * ecc - 1f);
// reverse sign from text to get prograde motion
float xdot = 1f * n * a_phy * Mathf.Sin(f) / denom;
float ydot = -1f * n * a_phy * (ecc + Mathf.Cos(f)) / denom;
if (!r_initial_outbound)
{
xdot *= -1f;
ydot *= -1f;
}
// Init functions are called in the engine by SetupOneBody and calls of parent vs children/grandchildren etc.
// can be in arbitrary order. A child will need info from parent for position and velocity. Ensure parent
// has inited.
INbodyInit centerInit = centerObject.GetComponent <INbodyInit>();
if (centerInit != null)
{
centerInit.InitNBody(physicalScale, massScale);
}
if (centerNbody.engineRef != null)
{
centerPos = GravityEngine.Instance().GetPhysicsPosition(centerNbody);
}
else
{
// setup - not yet added to GE
centerPos = centerNbody.initialPhysPosition;
}
Vector3 v_xy = new Vector3(xdot, ydot, 0);
Vector3 vphy = hyper_orientation * v_xy + centerNbody.vel_phys;
nbody.vel_phys = vphy;
}
/// <summary>
/// Apply scale to the orbit. This is used by the inspector scripts during
/// scene setup. Do not use at run-time.
/// </summary>
/// <param name="scale">Scale.</param>
public void ApplyScale(float scale)
{
if (paramBy == ParamBy.AXIS_A)
{
a_scaled = a * scale;
}
else if (paramBy == ParamBy.CLOSEST_P)
{
p_scaled = p * scale;
}
if (binaryNbody != null)
{
// this binary will have orbit w.r.t something. Make sure that update has been done
// check for initial condition setup (e.g. initial conditions for elliptical orbit)
GravityEngine ge = GravityEngine.Instance();
if (binaryNbody.engineRef == null)
{
INbodyInit initNbody = GetComponent <INbodyInit>();
if (initNbody != null)
{
initNbody.InitNBody(ge.physToWorldFactor, ge.massScale);
}
cmPosition = binaryNbody.initialPhysPosition;
}
else
{
cmPosition = ge.GetPhysicsPosition(binaryNbody);
}
}
else
{
cmPosition = transform.position * scale / GravityEngine.instance.physToWorldFactor;
}
UpdateOrbitParams();
// if there is a binaryNbody, then need to determine the CM position and velocity before the
SetupBodies();
}
/// <summary>
/// Inits the N body position and velocity based on the hyperbola parameters and the
/// position and velocity of the parent.
/// </summary>
/// <param name="physicalScale">Physical scale.</param>
public void InitNBody(float physicalScale, float massScale)
{
float a_phy = a / physicalScale;
NBody nbody = GetComponent <NBody>();
// Phase is TRUE anomoly f
float f = ThetaForR(r_initial);
// Murray and Dermot (2.20)
float n = Mathf.Sqrt((float)(centerNbody.mass * massScale) / (a_phy * a_phy * a_phy));
float denom = Mathf.Sqrt(ecc * ecc - 1f);
// reverse sign from text to get prograde motion
float xdot = 1f * n * a_phy * Mathf.Sin(f) / denom;
float ydot = -1f * n * a_phy * (ecc + Mathf.Cos(f)) / denom;
if (!r_initial_outbound)
{
xdot *= -1f;
ydot *= -1f;
}
// Init functions are called in the engine by SetupOneBody and calls of parent vs children/grandchildren etc.
// can be in arbitrary order. A child will need info from parent for position and velocity. Ensure parent
// has inited.
INbodyInit centerInit = centerObject.GetComponent <INbodyInit>();
if (centerInit != null)
{
centerInit.InitNBody(physicalScale, massScale);
}
SetTransform(physicalScale);
Vector3 v_xy = new Vector3(xdot, ydot, 0);
Vector3 vphy = ellipse_orientation * v_xy + centerNbody.vel_scaled;
nbody.vel_scaled = vphy;
}
