/// <summary>
/// Calculates the force necessary to avoid the closest spherical obstacle
/// </summary>
/// <returns>
/// Force necessary to avoid an obstacle, or Vector3.zero
/// </returns>
/// <remarks>
/// This method will iterate through all detected spherical obstacles that
/// are within MinTimeToCollision, and calculate a repulsion vector based
/// on them.
/// </remarks>
protected override Vector3 CalculateForce()
{
Vector3 avoidance = Vector3.zero;
if (Vehicle.Radar.Obstacles == null || !Vehicle.Radar.Obstacles.Any())
{
return(avoidance);
}
/*
* While we could just calculate movement as (Velocity * predictionTime)
* and save ourselves the substraction, this allows other vehicles to
* override PredictFuturePosition for their own ends.
*/
Vector3 futurePosition = Vehicle.PredictFutureDesiredPosition(_estimationTime);
#if ANNOTATE_AVOIDOBSTACLES
Debug.DrawLine(Vehicle.Position, futurePosition, Color.cyan);
#endif
// test all obstacles for intersection with my forward axis,
// select the one whose point of intersection is nearest
Profiler.BeginSample("Accumulate spherical obstacle influences");
for (int i = 0; i < Vehicle.Radar.Obstacles.Count; i++)
{
var sphere = Vehicle.Radar.Obstacles[i];
if (sphere == null || sphere.Equals(null))
{
continue; // In case the object was destroyed since we cached it
}
PathIntersection next = FindNextIntersectionWithSphere(Vehicle, futurePosition, sphere);
float avoidanceMultiplier = 1;
if (next.Intersect)
{
#if ANNOTATE_AVOIDOBSTACLES
Debug.DrawRay(Vehicle.Position, Vehicle.DesiredVelocity.normalized * next.Distance, Color.yellow);
#endif
avoidanceMultiplier = Vehicle.Radar.Obstacles.Count;
}
var distanceCurrent = Vehicle.Position - sphere.Position;
var distanceFuture = futurePosition - sphere.Position;
avoidance += avoidanceMultiplier * distanceCurrent / distanceFuture.sqrMagnitude;
}
Profiler.EndSample();
avoidance /= Vehicle.Radar.Obstacles.Count;
var newDesired = Vector3.Reflect(Vehicle.DesiredVelocity, avoidance);
#if ANNOTATE_AVOIDOBSTACLES
Debug.DrawLine(Vehicle.Position, Vehicle.Position + avoidance, Color.green);
Debug.DrawLine(Vehicle.Position, futurePosition, Color.blue);
Debug.DrawLine(Vehicle.Position, Vehicle.Position + newDesired, Color.white);
#endif
return(newDesired);
}
protected override Vector3 CalculateForce()
{
Profiler.BeginSample("Accumulating repulsion");
Vector3 accumulator = Vector3.zero;
int totalCount = 0;
var now = Time.time;
Vector3 futurePosition = Vehicle.PredictFutureDesiredPosition(_estimationTime);
for (int i = 0; i < _maxEvents; i++)
{
var timeDelta = now - _eventTimes[i];
if (timeDelta > 0)
{
var posDelta = futurePosition - _eventLocations[i];
if (posDelta.sqrMagnitude < _minDistanceForFearSqr)
{
totalCount++;
accumulator += posDelta / (timeDelta * _timeDeltaWeight);
#if ANNOTATE_REPULSION
Debug.DrawLine(futurePosition, _eventLocations[i], Color.red / (timeDelta * _timeDeltaWeight));
#endif
}
}
}
if (totalCount > 0)
{
accumulator.Normalize();
}
#if ANNOTATE_REPULSION
Debug.DrawLine(position, position + accumulator, Color.yellow);
Debug.DrawLine(position, futurePosition, Color.blue);
Debug.DrawLine(position + accumulator, futurePosition, Color.magenta);
#endif
Profiler.EndSample();
return(accumulator);
}
protected override Vector3 CalculateForce()
{
if (_menace == null || (Vehicle.Position - _menace.Position).sqrMagnitude > _sqrSafetyDistance)
{
return(Vector3.zero);
}
// offset from this to menace, that distance, unit vector toward menace
var position = Vehicle.PredictFutureDesiredPosition(_predictionTime);
Vector3 offset = _menace.Position - position;
float distance = offset.magnitude;
float roughTime = distance / _menace.Speed;
float predictionTime = ((roughTime > _predictionTime) ?
_predictionTime :
roughTime);
Vector3 target = _menace.PredictFuturePosition(predictionTime);
// This was the totality of SteerToFlee
Vector3 desiredVelocity = position - target;
return(desiredVelocity - Vehicle.DesiredVelocity);
}