public Vector3 GetForce(Steering steering)
{
if (isResponsibleForNeighbourUpdate)
{
// TODO: figure out how to add or remove neighbours automatically here or in neighbours
neighbours.Update();
}
/*
* Avoid collisions by determining for each neighbor when their paths will be closest to each other
* and then steer laterally to avoid collision.
* https://www.red3d.com/cwr/steer/Unaligned.html
*/
float distanceToBeginReacting = 4f * (steering.GetSize() + steering.GetStoppingDistance());
//Debug.Log(doubleStopDistance);
foreach (Neighbour <Steering> neighbour in neighbours)
{
if (neighbour.dd > distanceToBeginReacting * distanceToBeginReacting)
{
break;
}
Steering otherUnit = neighbour.obj;
Vector3 offset = otherUnit.GetPosition() - steering.GetPosition();
Vector3 relativeVelocity = steering.GetVelocity() - otherUnit.GetVelocity();
// Decrease the timeToCollision so that closestOffset is nonZero.
float combinedSize = steering.GetSize() + otherUnit.GetSize();
float timeToCollision = (offset.magnitude - combinedSize) / SteeringUtilities.parallelComponent(relativeVelocity, offset).magnitude;
if (timeToCollision > 2 * steering.GetStoppingTime())
{
continue;
}
Vector3 closestOffset = (offset - (timeToCollision * relativeVelocity));
float preferredDistance = 1.5f * combinedSize;
if (closestOffset.sqrMagnitude > preferredDistance * preferredDistance)
{
continue;
}
SteeringUtilities.drawDebugVector(steering, timeToCollision * steering.GetVelocity(), Color.cyan);
SteeringUtilities.drawDebugPoint(steering.GetPosition() + timeToCollision * steering.GetVelocity(), Color.cyan);
SteeringUtilities.drawDebugVector(otherUnit, timeToCollision * otherUnit.GetVelocity(), Color.cyan);
SteeringUtilities.drawDebugPoint(otherUnit.GetPosition() + timeToCollision * otherUnit.GetVelocity(), Color.cyan);
// TODO: for head-on collisions steer to the right
// Steer in the direction of the component of the collision normal that is perpindicular to the current velocity.
// This way the unit will turn instead of just slowing down.
// TODO: use an amount of acceleration proportionate to the time until collision and the severity of the collision
return(SteeringUtilities.scaledVector(steering.GetAcceleration(), SteeringUtilities.perpindicularComponent(-closestOffset, steering.GetVelocity())));
//return SteeringUtilities.getForceForDirection(steering, -closestOffset);
}
return(Vector3.zero);
}
// TODO: add functions to get and modify preferredDistance
public Vector3 GetForce(Steering steering)
{
Vector3 steeringVector = new Vector3(0f, 0f, 0f);
// steer away from each object that is too close with a weight of up to 0.5 for each
foreach (Neighbour <Steering> neighbour in neighbours)
{
if (neighbour.dd > preferredDistance * preferredDistance)
{
break;
}
Steering otherUnit = neighbour.obj;
Vector3 offset = otherUnit.GetPosition() - steering.GetPosition();
float currentDistance = Mathf.Sqrt(neighbour.dd);
// TODO: consider relative velocity when computing importance
float importance = (preferredDistance - currentDistance) / preferredDistance;
steeringVector += -importance * offset;
}
if (steeringVector.sqrMagnitude > 0)
{
// TODO: do something like arrival to avoid over-separating
return(SteeringUtilities.getForceForDirection(steering, steeringVector));
}
return(Vector3.zero);
}
public Vector3 GetForce(Steering steering)
{
if (steering.GetVelocity().sqrMagnitude == 0f)
{
float initialAngle = Random.Range(0f, 2 * Mathf.PI);
float sinAngle = Mathf.Sin(initialAngle);
wanderPoint = 2.4f * new Vector3(Mathf.Cos(initialAngle), Steering.YMult * sinAngle, Steering.ZMult * sinAngle);
}
if (steering.GetVelocity().sqrMagnitude > 0f && !hasMoved)
{
hasMoved = true;
wanderPoint = SteeringUtilities.scaledVector(2.4f, steering.GetVelocity());
}
float xNoise = Time.fixedDeltaTime * wanderNoise * Random.Range(-1f, 1f);
float yzNoise = Time.fixedDeltaTime * wanderNoise * Random.Range(-1f, 1f);
wanderPoint += new Vector3(xNoise, Steering.YMult * yzNoise, Steering.ZMult * yzNoise);
Vector3 forwardPoint = steering.GetPosition() + SteeringUtilities.scaledVector(1.41f, steering.GetVelocity());
// Constrain the wander point to the unit circle in front of the player.
wanderPoint = forwardPoint + (wanderPoint - forwardPoint).normalized;
//return SteeringUtilities.getForceForDirection(steering, wanderDirection);
//SteeringUtilities.drawDebugCircle(forwardPoint, 1f, Color.black, 32);
SteeringUtilities.drawDebugPoint(wanderPoint, Color.red);
return(SteeringUtilities.getSeekForce(steering, wanderPoint));
}
private RaycastHit Raycast(Steering steering, Vector3 directionVector, float raycastDistance)
{
RaycastHit hitInfo;
Physics.Raycast(steering.GetPosition(), directionVector, out hitInfo, raycastDistance, layerMask);
//SteeringUtilities.drawDebugVector(steering, SteeringUtilities.scaledVector(raycastDistance, directionVector), Color.white);
if (hitInfo.collider != null)
{
SteeringUtilities.drawDebugPoint(hitInfo.point, Color.magenta);
SteeringUtilities.drawDebugVector(steering, hitInfo.point - steering.GetPosition(), Color.magenta);
SteeringUtilities.drawDebugVector(hitInfo.point, hitInfo.normal, Color.white);
}
else
{
SteeringUtilities.drawDebugVector(steering, SteeringUtilities.scaledVector(raycastDistance, directionVector), new Color(Color.magenta.r, Color.magenta.g, Color.magenta.b, 0.25f));
}
return(hitInfo);
}
public Vector3 GetForce(Steering steering)
{
if (_target != null)
{
return(SteeringUtilities.getSeekForce(steering, _target.GetPosition()));
}
else
{
return(SteeringUtilities.getSeekForce(steering, _point));
}
}
public static void drawDebugVector(Steering steering, Vector3 offsetVector, Color color)
{
drawDebugVector(steering.GetPosition(), offsetVector, color);
}
public static Vector3 getSeekForce(Steering steering, Vector3 targetPosition)
{
return(getForceForDirection(steering, targetPosition - steering.GetPosition()));
}
// Performs a raycast and returns the normal of the collision or the zero vector.
private float RaycastDistance(Steering steering, Vector3 directionVector, float raycastDistance)
{
if (Steering.Using3D)
{
RaycastHit hitInfo = Raycast(steering, directionVector, raycastDistance);
return(hitInfo.collider == null ? raycastDistance : (hitInfo.point - steering.GetPosition()).magnitude);
}
RaycastHit2D hitInfo2D = Raycast2D(steering, directionVector, raycastDistance);
return(hitInfo2D.collider == null ? raycastDistance : ((Vector3)hitInfo2D.point - steering.GetPosition()).magnitude);
}
public Vector3 GetForce(Steering steering)
{
Vector3 currentOffset = target.GetPosition() - steering.GetPosition();
float dist = currentOffset.magnitude;
Vector3 unitV = steering.GetVelocity().normalized;
float parallelness = Vector3.Dot(unitV, target.GetVelocity().normalized);
float forwardness = Vector3.Dot(unitV, currentOffset / dist);
float halfsqrt2 = 0.707f;
int f = SteeringUtilities.intervalComp(forwardness, -halfsqrt2, halfsqrt2);
int p = SteeringUtilities.intervalComp(parallelness, -halfsqrt2, halfsqrt2);
// approximate how far to lead the target
float timeFactor = 1f;
// case logic based on (ahead, aside, behind) X (parallel, perp, anti-parallel)
switch (f)
{
case 1: //target is ahead
switch (p)
{
case 1:
timeFactor = 4f;
break;
case 0:
timeFactor = 1.8f;
break;
case -1:
timeFactor = 0.85f;
break;
}
break;
case 0: //target is aside
switch (p)
{
case 1:
timeFactor = 1f;
break;
case 0:
timeFactor = 0.8f;
break;
case -1:
timeFactor = 4f;
break;
}
break;
case -1: //target is behind
switch (p)
{
case 1:
timeFactor = 0.5f;
break;
case 0:
timeFactor = 2f;
break;
case -1:
timeFactor = 2f;
break;
}
break;
}
// Multiply the timeToArrive by some approximate constants based on how similar the two velocities are.
float approximateArrivalTime = dist / steering.GetMaxSpeed();
float improvedArrivalTimeEstimate = Mathf.Min(MAX_PREDICTION_TIME, approximateArrivalTime * timeFactor);
Vector3 newTargetPosition = (Vector3)target.GetPosition() + improvedArrivalTimeEstimate * target.GetVelocity();
SteeringUtilities.drawDebugVector(target, newTargetPosition - target.GetPosition(), Color.white);
SteeringUtilities.drawDebugVector(steering, newTargetPosition - steering.GetPosition(), Color.magenta);
return(SteeringUtilities.getForceForDirection(steering, newTargetPosition - steering.GetPosition()));
}