AstarAI.cs

Full source for the simple AI written in the Get Started Guide.It should be attached to a GameObject with a Seeker and a CharacterController also attached.

using UnityEngine;
using System.Collections;
// Note this line, if it is left out, the script won't know that the class 'Path' exists and it will throw compiler errors
// This line should always be present at the top of scripts which use pathfinding
using Pathfinding;

public class AstarAI : MonoBehaviour {
    public Transform targetPosition;

    private Seeker seeker;
    private CharacterController controller;

    public Path path;

    public float speed = 2;

    public float nextWaypointDistance = 3;

    private int currentWaypoint = 0;

    public float repathRate = 0.5f;
    private float lastRepath = -9999;

    public void Start () {
        seeker = GetComponent<Seeker>();
        controller = GetComponent<CharacterController>();
    }

    public void OnPathComplete (Path p) {
        Debug.Log("A path was calculated. Did it fail with an error? " + p.error);

        // Path pooling. To avoid unnecessary allocations paths are reference counted.
        // Calling Claim will increase the reference count by 1 and Release will reduce
        // it by one, when it reaches zero the path will be pooled and then it may be used
        // by other scripts. The ABPath.Construct or Seeker.StartPath methods will
        // take a path from the pool if possible. See also the documentation page about path pooling.
        p.Claim(this);
        if (!p.error) {
            if (path != null) path.Release(this);
            path = p;
            // Reset the waypoint counter so that we start to move towards the first point in the path
            currentWaypoint = 0;
        } else {
            p.Release(this);
        }
    }

    public void Update () {
        if (Time.time - lastRepath > repathRate && seeker.IsDone()) {
            lastRepath = Time.time+ Random.value*repathRate*0.5f;

            // Start a new path to the targetPosition, call the the OnPathComplete function
            // when the path has been calculated (which may take a few frames depending on the complexity)
            seeker.StartPath(transform.position, targetPosition.position, OnPathComplete);
        }

        if (path == null) {
            // We have no path to follow yet, so don't do anything
            return;
        }

        if (currentWaypoint > path.vectorPath.Count) return;
        if (currentWaypoint == path.vectorPath.Count) {
            Debug.Log("End Of Path Reached");
            currentWaypoint++;
            return;
        }

        // Direction to the next waypoint
        Vector3 dir = (path.vectorPath[currentWaypoint]-transform.position).normalized;
        dir *= speed;
        // Note that SimpleMove takes a velocity in meters/second, so we should not multiply by Time.deltaTime
        controller.SimpleMove(dir);

        // The commented line is equivalent to the one below, but the one that is used
        // is slightly faster since it does not have to calculate a square root
        //if (Vector3.Distance (transform.position,path.vectorPath[currentWaypoint]) < nextWaypointDistance) {
        if ((transform.position-path.vectorPath[currentWaypoint]).sqrMagnitude < nextWaypointDistance*nextWaypointDistance) {
            currentWaypoint++;
            return;
        }
    }
}