FPS游戏之AI

最近在做策划给的一些关于FPS类型的需求，Demo基本已经成型，接下来整理并记录，高手略过，不喜勿喷！！！

一个好的AI会使游戏的可玩性大大增加，我这里只是简单的AI。

大致思路：

设置好后怪物的巡逻路径点，正常情况下，怪物处于巡逻状态，每到一个路径点会停下来张望，如果player接近怪物达到一定的距离，怪物的状态会变成追踪状态，当距离player一定距离状态会变成攻击状态，当怪物追踪到距离路径包围盒一定距离状态会转换成Back状态，回到当前路径点状态切换回巡逻状态

怪物受攻击状态过程中涉及怪物受击打动画（小坑），怪物死亡动画（后续更新）

攻击过程中player全屏掉血（后续更新）

上代码（不完整，主要思路）
 

//AI状态
public enum AI_State {
    None,
    Patrol,//巡逻
    ChasingPlayer,//跟随
    AimingPlayer,//
    AttackingPlayer,//攻击
    Attacked,//受到攻击
    Back,//返回状态
    Dead,//死亡
}

//敌人种类
public enum Enemy_Type {
    Soldier,
}

//当前状态
public AI_State actualState = AI_State.Patrol;
private float chasingSpeed = 2f;//跟随速度
private float nomalPatrolSpeed = 2.0f;//巡逻速度
//追踪距离
private float chasingDistance = 6;
//攻击距离
private float attackDistance = 1.5f;
//最大追踪距离
private float maxChasingDistance = 22;
 //路径
public FPS_WaypointsRoute waypointRoute;//路径点
private int currentWayPoint = 0;//当前路径索引
[HideInInspector]
public Transform[] waypoints;
private float timeToWait = 3.0f;//到达一个路径点停留时间

private UnityEngine.AI.NavMeshAgent agent;//导航组件
private Animator animator;
private AnimatorStateInfo info;

 void Start () {
        player = GameObject.FindGameObjectWithTag("Player");
        agent = GetComponent<UnityEngine.AI.NavMeshAgent>();
        animator = GetComponent<Animator>();
      
        if (player)
            playerTransform = player.transform;

        //设置路径
        SetWaypoints();
        //设置随机等待时间
        SetTimeToWait();
        //设置初始路径点
        SetWaypoint(waypoints[0].position);

        if (waypoints.Length > 0) {
            finalGoal = waypoints[0].transform.position;
        }
        bountCenter = GetCenter(waypointRoute.transform);//所有路径点的包围盒
    }

 void Update () {


        if (animator) {
            info = animator.GetCurrentAnimatorStateInfo(0);
        }
        //路径包围盒距离Ai最大的距离
        if (Vector3.Distance(this.transform.position, bountCenter) > maxChasingDistance)                                         
        {
            actualState = AI_State.Patrol;
        }


if (actualState != AI_State.Attacked) {
                        if (playerActualDistance > chasingDistance) {
                            if (lastState == AI_State.AttackingPlayer || lastState == AI_State.ChasingPlayer || lastState == AI_State.Attacked) {
                                actualState = AI_State.Back;
                            } else {
                                actualState = AI_State.Patrol;
                            }
                        } else if (playerActualDistance <= chasingDistance && playerActualDistance >= attackDistance) {
                            if (!info.IsName("Attack")) {
                                actualState = AI_State.ChasingPlayer;
                            } else {
                                animator.ResetTrigger("AttackT");
                            }
                            if (animator) {
                                animator.ResetTrigger("AttackT");
                            }
                        } else if (playerActualDistance < attackDistance) {
                            actualState = AI_State.AttackingPlayer;
                        }
                    } else {
                        FPS_Kill.Instance.UnNomalStrike = false;
                        if (animator) {
                            animator.SetBool("Idle", false);
                        }
                        if (playerActualDistance < attackDistance) {
                            actualState = AI_State.AttackingPlayer;
                            if (animator)
                                animator.ResetTrigger("AttackT");
                        } else {
                            actualState = AI_State.Attacked;
                        }
                    }

 switch (actualState) {
            case AI_State.Patrol:

                if (waypoints.Length > 0) {

                    if (agent.remainingDistance > 0.5f && !waiting) {
                        agent.SetDestination(finalGoal);
                        if (animator) {
                            animator.SetBool("Idle",false);
                        }

                    } else if (!waiting &&  waitTimer < actualTimeToWait ) {
                        waiting = true;
                    }

                    if (waiting) {
                        if (animator) {
                            animator.SetBool("Idle", true);
                        }
                        StopMovement();
                        if (waitTimer < actualTimeToWait)
                            waitTimer += Time.deltaTime;
                        else
                            ChangeWaytpoint();
                    }
                }
                break;
            case AI_State.ChasingPlayer:
                if (animator) {
                    animator.SetBool("Idle", false);
                }
                agent.SetDestination(player.transform.position);
                lastState = AI_State.ChasingPlayer;
                break;
            case AI_State.AttackingPlayer:
                StopMovement();
                LookToTarget(player.transform.position);
                AttackPlayer();
                lastState = AI_State.AttackingPlayer;
                break;
            case AI_State.Back:
                agent.SetDestination(waypoints[currentWayPoint].transform.position);

                bloodValue = Mathf.Lerp(bloodValue, 10, (Time.time-temp)*0.001f);
                FPS_BloodStrip.Insatnce.ChangeBloodStrip(bloodValue / 10.0f, 0.0f, 1);

                if (agent.remainingDistance < 0.5f) {
                    actualState = AI_State.Patrol;
                    lastState = AI_State.None;
                    FPS_Kill.Instance.UnNomalStrike = false;
                    //回去进入巡逻状态满血
                    GetComponent<FPS_Health>().health = 10;
                    FPS_BloodStrip.Insatnce.ChangeBloodStrip(10 / 10.0f, 0.0f, 1);
                }

                break;
            case AI_State.Attacked:
                agent.SetDestination(player.transform.position);
                lastState = AI_State.Attacked;
                break;
            case AI_State.Dead:
                StopMovement();
                break;
        }
    



}

public void SetWaypoints() {
        if (waypointRoute) {
            waypoints = new Transform[waypointRoute.waypoints.Length];

            for (int i = 0; i < (waypoints.Length); i++) {
                waypoints[i] = waypointRoute.waypoints[i];

            }
        }
    }

    /// <summary>
    /// 停止移动
    /// </summary>
    void StopMovement() {
        if (agent != null) {
            agent.velocity = Vector3.zero;
           
        }
    }

    /// <summary>
    /// 巡逻等待时间
    /// </summary>
    void SetTimeToWait() {
        actualTimeToWait = Random.Range(timeToWait * 0.75f, -timeToWait * 0.75f) + timeToWait;
    }


    /// <summary>
    /// 更改路径点
    /// </summary>
    void ChangeWaytpoint() {
        waiting = false;

        currentWayPoint++;
        if (currentWayPoint >= waypoints.Length) {
            currentWayPoint = 0;
        }

        waitTimer = 0.0f;
        SetTimeToWait();

        SetWaypoint(waypoints[currentWayPoint].transform.position);
    }

    /// <summary>
    /// 设置路径点
    /// </summary>
    /// <param name="Pos"></param>
    void SetWaypoint(Vector3 Pos) {
        SetRandomPosVar(Pos);
        agent.SetDestination(finalGoal);
    }

    /// <summary>
    /// 设置目标路径点
    /// </summary>
    /// <param name="goal"></param>
    void SetRandomPosVar(Vector3 goal) {
        finalGoal = goal + new Vector3(Random.Range(-1, 1), 0, Random.Range(-1, 1));
    }