public static Vector3 Evade(SteeringActor actor, SteeringActor pursuer)
{
SteeringBehaviours.Forces attributes = actor.GetAttributes().Forces;
Vector3 toPursuer = pursuer.GetPosition() - actor.GetPosition();
float lookAhreadTime = toPursuer.magnitude / (attributes.MaxSpeed + pursuer.GetVelocity().magnitude);
return Flee(actor, pursuer.GetPosition() + (Vector3)pursuer.GetVelocity() * lookAhreadTime);
}
public static Vector3 Pursuit(SteeringActor actor, SteeringActor evader)
{
SteeringBehaviours.Forces attributes = actor.GetAttributes().Forces;
Vector3 toEvader = evader.GetPosition() - actor.GetPosition();
Vector3 thisHeading = actor.GetVelocity();
thisHeading.Normalize();
Vector3 evaderHeading = evader.GetVelocity();
evaderHeading.Normalize();
float relativeHeading = Vector3.Dot(thisHeading, evaderHeading);
float tresholdAngleAcos = Mathf.Acos(attributes.PursuitThresholdAngle);
if (Vector3.Dot(toEvader, thisHeading) > 0 && (relativeHeading < -tresholdAngleAcos))
{
return Seek(actor, evader.GetPosition());
}
// the look ahead time is proportional to the distance between the evader
// and the pursuer; and is inversely proportional to the sum of the agents velocities
float lookAheadTime = toEvader.magnitude / (attributes.MaxSpeed + evader.GetVelocity().magnitude);
// Now seek to the predicted future position of the evader
return Seek(actor, evader.GetPosition() + (Vector3) evader.GetVelocity() * lookAheadTime);
}
public static Vector3 Arrive(SteeringActor actor, Vector3 targetPos, SteeringBehaviours.Deceleration deceleration)
{
SteeringBehaviours.Forces attributes = actor.GetAttributes().Forces;
Vector3 toTarget = targetPos - actor.GetPosition();
float dist = toTarget.magnitude;
if (dist <= 0)
{
return new Vector3();
}
float decelerationTweaker = 0.3f;
float speed = dist / ((float)deceleration * decelerationTweaker);
speed = Mathf.Min(speed, attributes.MaxSpeed);
Vector3 desiredVelocity = toTarget * speed / dist;
return desiredVelocity;// - GetVelocity();
}
public static Vector3 Flee(SteeringActor actor, Vector3 targetPos)
{
SteeringBehaviours.Forces attributes = actor.GetAttributes().Forces;
Vector3 fromTarget = actor.GetPosition() - targetPos;
fromTarget.Normalize();
Vector3 desiredVelocity = fromTarget * attributes.MaxSpeed;
return desiredVelocity;// - GetVelocity();
}
public static Vector3 Seek(SteeringActor actor, Vector3 targetPos)
{
SteeringBehaviours.Forces attributes = actor.GetAttributes().Forces;
Vector3 toTarget = (targetPos - actor.GetPosition());
toTarget.Normalize();
Vector3 desiredVelocity = toTarget * attributes.MaxSpeed;
return desiredVelocity;// - GetVelocity();
}
public static bool IsTargetFront(SteeringActor actor, SteeringActor target)
{
Vector3 toTarget = target.GetPosition() - actor.GetPosition();
toTarget.Normalize();
return Vector3.Dot(actor.GetForward(), toTarget) > 0;
}
