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);
}
