private Vector3 Hide(AIAgent hunter, List <AIObject> obstacles)
{
float DistToClosest = float.MaxValue;
Vector3 BestHidingSpot = Vector3.zero;
AIObject closest;
for (int i = 0; i < obstacles.Count; ++i)
{
AIObject curOb = obstacles[i];
Vector3 hidingSpot = GetHidingPosition(curOb.VPos(), curOb.BRadius(), hunter.VPos());
float dist = (m_entity.VPos() - hidingSpot).sqrMagnitude;
DistToClosest = dist;
BestHidingSpot = hidingSpot;
if (dist < DistToClosest)
{
closest = curOb;
}
}
//if no suitable obstacles found then Evade the hunter
if (DistToClosest == float.MaxValue)
{
return(Evade(hunter));
}
//else use Arrive on the hiding spot
return(Arrive(BestHidingSpot, Deceleration.fast));
}
public void TagObstaclesWithinViewRange(AIAgent entity, float radius)
{
IEnumerator <AIObject> it = m_Obstacles.GetEnumerator();
while (it.MoveNext())
{
AIObject curEntity = it.Current;
//first clear any current tag
curEntity.UnTagging();
Vector3 to = curEntity.VPos() - entity.VPos();
//the bounding radius of the other is taken into account by adding it
//to the range
float range = radius + curEntity.BRadius();
//if entity within range, tag for further consideration. (working in
//distance-squared space to avoid sqrts)
if ((curEntity.GetHashCode() != entity.GetHashCode()) &&
(to.sqrMagnitude < range * range))
{
curEntity.Tagging();
}
}
}
public bool Overlapped(AIObject ob, List <AIObject> conOb, float MinDistBetweenObstacles)
{
IEnumerator <AIObject> it = conOb.GetEnumerator();
while (it.MoveNext())
{
AIObject tmp = it.Current;
if (MathUtil.TwoCirclesOverlapped(ob.VPos(),
ob.BRadius() + MinDistBetweenObstacles,
tmp.VPos(),
tmp.BRadius()))
{
return(true);
}
}
return(false);
}
public void SetCrosshair(Vector3 p, string id = "basic")
{
Vector3 ProposedPosition = p;
//make sure it's not inside an obstacle
for (int i = 0; i < m_Obstacles.Count; ++i)
{
AIObject curOb = m_Obstacles[i];
if (MathUtil.PointInCircle(curOb.VPos(), curOb.BRadius(), ProposedPosition))
{
return;
}
}
AIGroup aiGroup = GetAIGroup(id);
if (aiGroup != null)
{
aiGroup.SetCrosshair(p);
}
}
/**
* Given a vector of obstacles, this method returns a steering force
* that will prevent the agent colliding with the closest obstacle
*/
private Vector3 ObstacleAvoidance(List <AIObject> obstacles)
{
//*
//the detection box length is proportional to the agent's velocity
m_fDBoxLength = minDetectionBoxLength
+ (m_entity.Speed() / m_entity.MaxSpeed())
* minDetectionBoxLength;
//tag all obstacles within range of the box for processing
m_entity.World().TagObstaclesWithinViewRange(m_entity, m_fDBoxLength);
//this will keep track of the closest intersecting obstacle (CIB)
AIObject ClosestIntersectingObstacle = null;
//this will be used to track the distance to the CIB
float DistToClosestIP = float.MaxValue;
//this will record the transformed local coordinates of the CIB
Vector3 LocalPosOfClosestObstacle = Vector3.zero;
IEnumerator <AIObject> it = obstacles.GetEnumerator();
for (int i = 0; i < obstacles.Count; ++i)
{
//if the obstacle has been tagged within range proceed
AIObject curOb = obstacles[i];
if (curOb.Tag)
{
//calculate this obstacle's position in local space
Vector3 LocalPos = MathUtil.PointToLocalSpace(curOb.VPos(),
m_entity.Heading(),
m_entity.Side(),
m_entity.VPos());
// entity Heading and LocalPos is
if (Vector3.Dot(LocalPos, Vector3.forward) > 0)
{
//than its radius + half the width of the detection box then there
//is a potential intersection.
float ExpandedRadius = curOb.BRadius() + m_entity.BRadius();
if (Mathf.Abs(LocalPos.x) < ExpandedRadius)
{
//test to see if this is the closest so far. If it is keep a
//record of the obstacle and its local coordinates
if (LocalPos.magnitude < DistToClosestIP)
{
DistToClosestIP = LocalPos.magnitude;
ClosestIntersectingObstacle = curOb;
LocalPosOfClosestObstacle = LocalPos;
}
}
}
}
}
//if we have found an intersecting obstacle, calculate a steering
//force away from it
Vector3 steeringForce = Vector3.zero;
if (ClosestIntersectingObstacle != null)
{
//should be
//the closer the agent is to an object, the stronger the
//steering force should be
float multiplier = 1.0f + (m_fDBoxLength - LocalPosOfClosestObstacle.z)
/ m_fDBoxLength;
//calculate the lateral force
steeringForce.x = (ClosestIntersectingObstacle.BRadius()
- LocalPosOfClosestObstacle.x) * multiplier;
//apply a braking force proportional to the obstacles distance from
//the vehicle.
float BrakingWeight = 0.2f;
steeringForce.z = (ClosestIntersectingObstacle.BRadius()
- LocalPosOfClosestObstacle.z)
* BrakingWeight;
}
//finally, convert the steering vector from local to world space
return(MathUtil.VectorToWorldSpace(steeringForce,
m_entity.Heading(),
m_entity.Side()));
}