/// <summary>
/// Author: Ziqi Li
/// Function to get a random target for a flock of birds
/// </summary>
/// <param name="list"></param>
/// <returns></returns>
Vector3 GetRandTarget(FlocksList list)
{
Vector3 randTarget;
Vector3 avgPosition = GetFlockAvgPosition(list);
Vector3 avgVelocity = GetFlockAvgVelocity(list).normalized;
avgVelocity.y *= MotionMultiplier_Y; // decrease the impact of vertical movement
// find a random target in the moving direction of this flock
Vector3 centerPos = FlyingAreaCenter.transform.position;
// ignore z-axis
Vector3 avgPos_xy = new Vector3(avgPosition.x, avgPosition.y, 0);
centerPos.z = 0;
// if this flock is out of flying range, set the center of flying area as target
if (Vector3.Distance(avgPos_xy, centerPos) > MaxRangeFromCenter)
{
Vector2 rand = Random.insideUnitCircle * RandTargetRadius;
randTarget = new Vector3(centerPos.x + rand.x, centerPos.y + rand.y, avgPosition.z);
}
else // randomly select a forward point
{
Vector3 randCircleCenter = avgPosition + avgVelocity * RandTargetMagnitude;
Vector2 rand = Random.insideUnitCircle * RandTargetRadius;
randTarget = new Vector3(randCircleCenter.x + rand.x, randCircleCenter.y + rand.y, avgPosition.z);
}
return(randTarget);
}
/// <summary>
/// Author: Ziqi Li
/// Function to get the average velocity of a flock of units
/// </summary>
/// <param name="list"></param>
Vector3 GetFlockAvgVelocity(FlocksList list)
{
Vector3 avgVelocity = Vector3.zero;
foreach (GameObject unit in list.Birds)
{
avgVelocity += unit.GetComponent <Rigidbody>().velocity;
}
return(avgVelocity / list.Birds.Count);
}
/// <summary>
/// Author: Ziqi Li
/// Function to get the geometric center of a flock of units
/// </summary>
/// <param name="list"></param>
Vector3 GetFlockAvgPosition(FlocksList list)
{
Vector3 avgPosition = Vector3.zero;
foreach (GameObject unit in list.Birds)
{
avgPosition += unit.transform.position;
}
return(avgPosition / list.Birds.Count);
}