public override Steering GetSteering()
{
Steering steering = new Steering();
if (avoidBullets)
{
GameObject[] bullets = GameObject.FindGameObjectsWithTag("bulletPlayer");
targets = new Transform[bullets.Length];
targetAgents = new SteeringBehaviours.Agent[targets.Length];
targetRigidbodys = new Rigidbody[targets.Length];
for (int j = 0; j < bullets.Length; j++)
{
targets[j] = bullets[j].transform;
if (useRigidbodyOfBullet)
{
targetRigidbodys[j] = targets[j].gameObject.HasComponent <Rigidbody>() ?
targets[j].gameObject.GetComponent <Rigidbody>() : null;
}
else
{
Destroy(targets[j].gameObject.GetComponent <Rigidbody>());
}
}
}
// 1. Find the target that's closest to collision
// Store the first collision time
float shorestTime = Mathf.Infinity;
// Store the target that collides then, and other data
// that we will need and avoid recalculating
Transform firstTarget = null;
float firstMinSeparation = 0.0f;
float firstDistance = 0.0f;
Vector3 firstRelativePos = Vector3.zero;
Vector3 firstRelativeVel = Vector3.zero;
// Loop through each target
int i = 0;
foreach (Transform new_target in targets)
{
// Calculate the time to collision
Vector3 relativePos = new_target.position - transform.position;
Vector3 relativeVel = targetAgents[i] != null ?
targetAgents[i].velocity - agent.velocity :
targetRigidbodys[i].velocity - agent.velocity;
float relativeSpeed = relativeVel.magnitude;
i++;
if (relativeSpeed == 0)
{
continue;
}
float timeToCollision = Vector3.Dot(relativePos, relativeVel);
timeToCollision /= relativeSpeed * relativeSpeed * -1;
// Check if it is going to be a collision at all
float distance = relativePos.magnitude;
float minSeparation = distance - relativeSpeed * timeToCollision;
if (minSeparation > 2 * radius)
{
continue;
}
// Check if it is the shortest
if (timeToCollision > 0 && timeToCollision < shorestTime)
{
// Store the time, target and other data
shorestTime = timeToCollision;
firstTarget = new_target;
firstMinSeparation = minSeparation;
firstDistance = distance;
firstRelativePos = relativePos;
firstRelativeVel = relativeVel;
}
}
target = firstTarget != null? firstTarget.gameObject : null;
// 2. Calculate the steering
// If we have no target, then exit
if (firstTarget == null)
{
return(steering);
}
// Update the target
// If we're going to hit exactly, or if we're already
// colliding, then do the steering based on current position
if (firstMinSeparation <= 0 || firstDistance < 2 * radius)
{
if (!avoidBullets)
{
firstRelativePos = firstTarget.position;
}
else
{
Vector3 heading = firstTarget.position - transform.position;
int dir = ExtensionMethods.AngleDir(transform.forward, heading, transform.up);
firstRelativePos = transform.right * dir * 250 + transform.forward * 20;
}
}
// Otherwise calculate the future relative position
else if (!avoidBullets)
{
firstRelativePos += firstRelativeVel * shorestTime;
}
else
{
return(steering);
}
// Avoid the target
firstRelativePos.Normalize();
if (!avoidBullets)
{
steering.linear = -firstRelativePos * agent.maxAccel;
}
else
{
steering.linear = -firstRelativePos * agent.maxAccel * 80;
}
return(steering);
}