public float PredictNearestApproachTime(IRGKRacer other)
{
// imagine we are at the origin with no velocity,
// compute the relative velocity of the other vehicle
Vector3 myVelocity = Velocity;
Vector3 otherVelocity = other.Velocity;
Vector3 relVelocity = otherVelocity - myVelocity;
float relSpeed = relVelocity.magnitude;
// for parallel paths, the vehicles will always be at the same distance,
// so return 0 (aka "now") since "there is no time like the present"
if (relSpeed == 0)
{
return(0);
}
// Now consider the path of the other vehicle in this relative
// space, a line defined by the relative position and velocity.
// The distance from the origin (our vehicle) to that line is
// the nearest approach.
// Take the unit tangent along the other vehicle's path
Vector3 relTangent = relVelocity / relSpeed;
// find distance from its path to origin (compute offset from
// other to us, find length of projection onto path)
Vector3 relPosition = Position - other.Position;
float projection = Vector3.Dot(relTangent, relPosition);
return(projection / relSpeed);
}
private void FilterDetected()
{
if (ThreatRivals == null)
{
ThreatRivals = new List <IRGKRacer>();
}
ThreatRivals.Clear();
foreach (var ApproachingObject in DedectedObjects)
{
GameObject ApproachingVehicle = null;
ApproachingVehicle = GetParent(ApproachingObject.transform);
//AI_Brain ApproacingAI = ApproachingVehicle.GetComponent<AI_Brain>();
IRGKRacer ApproacingAI = (IRGKRacer)ApproachingVehicle.GetComponent(typeof(IRGKRacer));
if (ApproacingAI != null && ApproachingVehicle != this.gameObject)
{
ThreatRivals.Add(ApproacingAI);
if (ShowNavDebugLines)
{
Debug.DrawLine(this.Position, ApproachingObject.transform.position, Color.magenta);
}
}
}
DedectedRacerCount = ThreatRivals.Count;
}
protected float ComputeNearestApproachPositions(IRGKRacer other, float time, ref Vector3 ourPosition, ref Vector3 hisPosition, float ourSpeed, Vector3 ourForward)
{
Vector3 myTravel = ourForward * ourSpeed * time;
Vector3 otherTravel = other.CachedTransform.forward * other.Speed * time;
ourPosition = Position + myTravel;
hisPosition = other.Position + otherTravel;
return(Vector3.Distance(ourPosition, hisPosition));
}
public float PredictNearestApproachTime(IRGKRacer other)
{
Vector3 myVelocity = Velocity;
Vector3 otherVelocity = other.Velocity;
Vector3 relVelocity = otherVelocity - myVelocity;
float relSpeed = relVelocity.magnitude;
if (relSpeed == 0)
{
return(0);
}
Vector3 relTangent = relVelocity / relSpeed;
Vector3 relPosition = Position - other.Position;
float projection = Vector3.Dot(relTangent, relPosition);
return(projection / relSpeed);
}
protected float ComputeNearestApproachPositions(IRGKRacer other, float time, ref Vector3 ourPosition, ref Vector3 hisPosition)
{
return(ComputeNearestApproachPositions(other, time, ref ourPosition, ref hisPosition, Speed, myTransform.forward));
}
protected float CalculateSteerFactor()
{
/*
* // first priority is to prevent immediate interpenetration
* Vector3 separation = steerToAvoidCloseNeighbors (0, others);
* if (separation != Vector3.zero)
* {
* return separation;
* }
*/
// otherwise, go on to consider potential future collisions
Steer = 0;
IRGKRacer threat = null;
// Time (in seconds) until the most immediate collision threat found
// so far. Initial value is a threshold: don't look more than this
// many frames into the future.
float minTime = CollisionAvoidTime;
Vector3 threatPositionAtNearestApproach = Vector3.zero;
Vector3 ourPositionAtNearestApproach = Vector3.zero;
// for each of the other vehicles, determine which (if any)
// pose the most immediate threat of collision.
foreach (var other in ThreatRivals)
{
if (other != this) //&& !other.AIWillAvoid && AICanAvoid
{
// avoid when future positions are this close (or less)
float collisionDangerThreshold = this.DedectionRadius;
// predicted time until nearest approach of "this" and "other"
float time = PredictNearestApproachTime(other);
// If the time is in the future, sooner than any other
// threatened collision...
if ((time >= 0) && (time < minTime))
{
// if the two will be close enough to collide,
// make a note of it
Vector3 ourPos = Vector3.zero;
Vector3 hisPos = Vector3.zero;
float dist = ComputeNearestApproachPositions(other, time, ref ourPos, ref hisPos);
if (dist < collisionDangerThreshold)
{
minTime = time;
threat = other;
threatPositionAtNearestApproach = hisPos;
ourPositionAtNearestApproach = ourPos;
}
}
}
}
// if a potential collision was found, compute steering to avoid
if (threat != null)
{
// parallel: +1, perpendicular: 0, anti-parallel: -1
float parallelness = Vector3.Dot(transform.forward, threat.CachedTransform.forward);
//Debug.Log("Parallel " + parallelness + " " + _avoidAngleCos + " " + threatPositionAtNearestApproach);
if (parallelness < -CollisionAvoidAngleCos)
{
// anti-parallel "head on" paths:
// steer away from future threat position
Vector3 offset = threatPositionAtNearestApproach - this.Position;
float sideDot = Vector3.Dot(offset, transform.right);
Steer = (sideDot > 0) ? -CollisionAvoidFactor : CollisionAvoidFactor;
}
else if (parallelness > CollisionAvoidAngleCos)
{
// parallel paths: steer away from threat
Vector3 offset = threat.Position - this.Position;
float sideDot = Vector3.Dot(offset, transform.right);
Steer = (sideDot > 0) ? -CollisionAvoidFactor : CollisionAvoidFactor;
//AIAvoidingRivalAvoidPosition = (sideDot > 0) ? eAIRivalPosition.Right : eAIRivalPosition.Left;
//AIAvoidingRivalRoadPosition = threat.AICurrentRoadPosition;
}
else
{
/*
* Perpendicular paths: steer behind threat
*
* Only the slower vehicle attempts this, unless that
* slower vehicle is static. If both have the same
* speed, then the one with the lowest index falls
* behind.
*
* Something to test is making a slower vehicle fall
* behind, while a faster vehicle cuts ahead.
*/
if (this.Speed < threat.Speed ||
threat.Speed == 0 ||
gameObject.GetInstanceID() < threat.CachedGameObject.GetInstanceID())
{
float sideDot = Vector3.Dot(transform.right, threat.Velocity);
Steer = (sideDot > 0) ? -1.0f : 1.0f;
}
}
/* Steer will end up being applied as a multiplier to the
* vehicle's side vector. If we simply apply te -1/+1 being
* assigned above, then we'll end up with a unit displacement
* from the other object's position. We should account for
* both its radius and our own.
*/
//steer *= this.DedectionRadius+ threat.DedectionRadius;
}
else
{
//AIAvoidingRivalAvoidPosition = eAIRivalPosition.NoRival;
}
//if
// (DedectedCount > 1)
//{ return 0; }
//else
//{
// return Steer;
//}
return(Steer);
}
protected float CalculateSteerFactor()
{
Steer = 0;
IRGKRacer threat = null;
float minTime = CollisionAvoidTime;
Vector3 threatPositionAtNearestApproach = Vector3.zero;
Vector3 ourPositionAtNearestApproach = Vector3.zero;
foreach (var other in ThreatRivals)
{
if (other != this)
{
float collisionDangerThreshold = this.DedectionRadius;
float time = PredictNearestApproachTime(other);
if ((time >= 0) && (time < minTime))
{
Vector3 ourPos = Vector3.zero;
Vector3 hisPos = Vector3.zero;
float dist = ComputeNearestApproachPositions(other, time, ref ourPos, ref hisPos);
if (dist < collisionDangerThreshold)
{
minTime = time;
threat = other;
threatPositionAtNearestApproach = hisPos;
ourPositionAtNearestApproach = ourPos;
}
}
}
}
if (threat != null)
{
float parallelness = Vector3.Dot(transform.forward, threat.CachedTransform.forward);
if (parallelness < -CollisionAvoidAngleCos)
{
Vector3 offset = threatPositionAtNearestApproach - this.Position;
float sideDot = Vector3.Dot(offset, transform.right);
Steer = (sideDot > 0) ? -CollisionAvoidFactor : CollisionAvoidFactor;
}
else if (parallelness > CollisionAvoidAngleCos)
{
Vector3 offset = threat.Position - this.Position;
float sideDot = Vector3.Dot(offset, transform.right);
Steer = (sideDot > 0) ? -CollisionAvoidFactor : CollisionAvoidFactor;
AIAvoidingRivalAvoidPosition = (sideDot > 0) ? eAIRivalPosition.Right : eAIRivalPosition.Left;
AIAvoidingRivalRoadPosition = threat.CurrentRoadPosition;
}
else
{
if (this.Speed < threat.Speed ||
threat.Speed == 0 ||
gameObject.GetInstanceID() < threat.CachedGameObject.GetInstanceID())
{
float sideDot = Vector3.Dot(transform.right, threat.Velocity);
Steer = (sideDot > 0) ? (-1 * 1) : 1;
}
}
}
else
{
AIAvoidingRivalAvoidPosition = eAIRivalPosition.NoRival;
}
return(Steer);
}
