// -----------------------------------------------------------------
/// <summary>
/// Compute the new velocity for one entity
/// </summary>
// -----------------------------------------------------------------
protected void UpdateVelocity(int start, NBodyValue valA, float timedelta)
{
int length = m_localIDList.Length;
for (int j = start + 1; j < length; j++)
{
UUID idB = m_localIDList[j];
if (idB == UUID.Zero)
{
continue;
}
NBodyValue valB = m_entityList[idB];
VelocityPair vp = ComputeVelocityDelta(valA, valB);
if (valA.CanMove && valB.CanAttract)
{
valA.Velocity += vp.ABVelocity * timedelta;
}
if (valB.CanMove && valA.CanAttract)
{
Vector3 nv = valB.Velocity + (vp.BAVelocity * timedelta);
valB.Velocity = nv;
}
}
}
// -----------------------------------------------------------------
/// <summary>
///
/// </summary>
// -----------------------------------------------------------------
public void Dump()
{
m_log.WarnFormat("[N-BodyGroup] dump entity list");
lock (m_entityList)
{
//foreach (KeyValuePair<UUID,NBodyValue> kp in m_entityList)
// m_log.WarnFormat("[N-BodyGroup] PRE id={0}, mass={1}, velocity={2}, pos={3}",
// kp.Key,kp.Value.Mass,kp.Value.Velocity,kp.Value.Position);
// iterate through the entities that can move
foreach (KeyValuePair <UUID, NBodyValue> kpmover in m_entityList)
{
if (!kpmover.Value.CanMove)
{
continue;
}
SceneObjectPart sopmover = m_scene.GetSceneObjectPart(kpmover.Key);
if (sopmover == null)
{
continue;
}
// Copy the position in from the scene
kpmover.Value.Position = OSPosition2NBPosition(sopmover.AbsolutePosition);
Vector3 velocity = ComputeInitialVelocity(kpmover.Value);
// iterate through the entities that can attract
foreach (KeyValuePair <UUID, NBodyValue> kpattractor in m_entityList)
{
if (!kpattractor.Value.CanAttract)
{
continue;
}
SceneObjectPart sopattractor = m_scene.GetSceneObjectPart(kpattractor.Key);
if (sopattractor == null)
{
continue;
}
if (sopattractor == sopmover)
{
continue;
}
// Copy the current position in from the scene
kpattractor.Value.Position = OSPosition2NBPosition(sopattractor.AbsolutePosition);
// Compute the change in velocity caused by this
VelocityPair vp = ComputeVelocityDelta(kpmover.Value, kpattractor.Value);
m_log.WarnFormat("[N-BodyGroup] {0}->{1} : {2}", kpmover.Key, kpattractor.Key, vp.ABVelocity);
velocity += vp.ABVelocity;
}
m_log.WarnFormat("[N-BodyGroup] ****** {0} : {1}", kpmover.Key, velocity);
}
}
}
// -----------------------------------------------------------------
/// <summary>
///
/// </summary>
// -----------------------------------------------------------------
protected override VelocityPair ComputeVelocityDelta(NBodyValue v1, NBodyValue v2)
{
UInt32 v1ID = v1.LocalID;
UInt32 v2ID = v2.LocalID;
Vector3 direction = Vector3.Normalize(v2.Position - v1.Position);
VelocityPair vp = new VelocityPair();
vp.ABVelocity = direction * CachedAttraction[(int)v1ID][(int)v2ID];
vp.BAVelocity = (-direction) * CachedAttraction[(int)v2ID][(int)v1ID];
return(vp);
}
// -----------------------------------------------------------------
/// <summary>
///
/// </summary>
// -----------------------------------------------------------------
protected override VelocityPair ComputeVelocityDelta(NBodyValue v1, NBodyValue v2)
{
VelocityPair vp = new VelocityPair();
Vector3 direction = Vector3.Normalize(v2.Position - v1.Position);
double dsquared = Vector3.DistanceSquared(v1.Position, v2.Position);
if (dsquared == 0)
{
dsquared = 0.0000000001;
}
// F = s * (m1 * m2) / d^2
// acceleration is the similarity attraction * mass of the attractor divided
// by the distance separating the body and attractor
double force = GravitationalConstant * v1.Mass * v2.Mass / dsquared;
// a = F/m
vp.ABVelocity = direction * (float)(force / v1.Mass);
vp.BAVelocity = (-direction) * (float)(force / v2.Mass);
return(vp);
}
// -----------------------------------------------------------------
/// <summary>
///
/// </summary>
// -----------------------------------------------------------------
protected override VelocityPair ComputeVelocityDelta(NBodyValue v1, NBodyValue v2)
{
VelocityPair vp = new VelocityPair();
Vector3 direction = Vector3.Normalize(v2.Position-v1.Position);
double dsquared = Vector3.DistanceSquared(v1.Position,v2.Position);
if (dsquared == 0)
dsquared = 0.0000000001;
// F = s * (m1 * m2) / d^2
// acceleration is the similarity attraction * mass of the attractor divided
// by the distance separating the body and attractor
double force = GravitationalConstant * v1.Mass * v2.Mass / dsquared;
// a = F/m
vp.ABVelocity = direction * (float)(force / v1.Mass);
vp.BAVelocity = (-direction) * (float)(force / v2.Mass);
return vp;
}
// -----------------------------------------------------------------
/// <summary>
///
/// </summary>
// -----------------------------------------------------------------
protected override VelocityPair ComputeVelocityDelta(NBodyValue v1, NBodyValue v2)
{
UInt32 v1ID = v1.LocalID;
UInt32 v2ID = v2.LocalID;
Vector3 direction = Vector3.Normalize(v2.Position - v1.Position);
VelocityPair vp = new VelocityPair();
vp.ABVelocity = direction * CachedAttraction[(int)v1ID][(int)v2ID];
vp.BAVelocity = (-direction) * CachedAttraction[(int)v2ID][(int)v1ID];
return vp;
}
