public Vector3 GetForce(Steering steering)
{
Vector3 currentOffset = target.GetPosition() - steering.GetPosition();
float dist = currentOffset.magnitude;
Vector3 unitV = steering.GetVelocity().normalized;
float parallelness = Vector3.Dot(unitV, target.GetVelocity().normalized);
float forwardness = Vector3.Dot(unitV, currentOffset / dist);
float halfsqrt2 = 0.707f;
int f = SteeringUtilities.intervalComp(forwardness, -halfsqrt2, halfsqrt2);
int p = SteeringUtilities.intervalComp(parallelness, -halfsqrt2, halfsqrt2);
// approximate how far to lead the target
float timeFactor = 1f;
// case logic based on (ahead, aside, behind) X (parallel, perp, anti-parallel)
switch (f)
{
case 1: //target is ahead
switch (p)
{
case 1:
timeFactor = 4f;
break;
case 0:
timeFactor = 1.8f;
break;
case -1:
timeFactor = 0.85f;
break;
}
break;
case 0: //target is aside
switch (p)
{
case 1:
timeFactor = 1f;
break;
case 0:
timeFactor = 0.8f;
break;
case -1:
timeFactor = 4f;
break;
}
break;
case -1: //target is behind
switch (p)
{
case 1:
timeFactor = 0.5f;
break;
case 0:
timeFactor = 2f;
break;
case -1:
timeFactor = 2f;
break;
}
break;
}
// Multiply the timeToArrive by some approximate constants based on how similar the two velocities are.
float approximateArrivalTime = dist / steering.GetMaxSpeed();
float improvedArrivalTimeEstimate = Mathf.Min(MAX_PREDICTION_TIME, approximateArrivalTime * timeFactor);
Vector3 newTargetPosition = (Vector3)target.GetPosition() + improvedArrivalTimeEstimate * target.GetVelocity();
SteeringUtilities.drawDebugVector(target, newTargetPosition - target.GetPosition(), Color.white);
SteeringUtilities.drawDebugVector(steering, newTargetPosition - steering.GetPosition(), Color.magenta);
return(SteeringUtilities.getForceForDirection(steering, newTargetPosition - steering.GetPosition()));
}