Object moving forward before it starts functioning

Question

Hello, I wanted to make an enemy come out of doors and then start following the player. The enemy already follows the player, but when I put it behind doors it just starts moving towards the player and comes trought the wall next to the door. So I wanted to ask if there is a way the enemy would come out of the door first and then start following the player. I would appreciate your help.

Answer 1

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Answer by Dray · Jan 11, 2018 at 03:00 PM

Generic question, generic answer. ;) Define multiple states:

 public class EnemyScript: MonoBehaviour {
     private enum EnemyState {WalkingDoor, FollowingPlayer};  
 
     public Transform target; // your point in front of the door
     public float speed = 1f; // how fast the GameObject moves while exiting
     private EnemyState enemyState = EnemyScript.EnemyState.WalkingDoor; // current state
 
     void Update() {
         switch (enemyState ) {
             case EnemyScript.EnemyState.WalkingDoor:
                 // move towards the target
                 transform.position = Vector3.MoveTowards(transform.position, target.position, speed * Time.deltaTime);

                 // when close enough to the target, switch to following
                 if (Vector3.Distance(target.position, transform.position) < 0.1f) {
                     state = EnemyScript.EnemyState.FollowingPlayer;
                 }
             break;
 
             case EnemyScript.EnemyState.FollowingPlayer:
                 // run your follow-the-player-logic ...
             break;
         }
     }
 }

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PlatPlayz · Jan 11, 2018 at 03:02 PM 0

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That's the problem, I'm not sure how the leaving-the-door-logic should look like.

Dray PlatPlayz · Jan 11, 2018 at 03:12 PM 0

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I see, okay so basically it sounds like what you need to do is:

$$anonymous$$ove your object to a certain target over a certain time (some point straight in front of your door)
Eventually run an animation on your enemy model and on the door(?)

This line of code moves a GameObject towards your target:

 Transform target; // <- you decide where this comes from, could also use a Vector3
 float speed = 1f;
 transform.position = Vector3.$$anonymous$$oveTowards(transform.position, target.position, speed * Time.deltaTime);

PlatPlayz Dray · Jan 11, 2018 at 03:19 PM 0

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I've made a small picture to show you exactly what I mean. As you see on the picture, the enemy spawns on a set position behind the door, moves straight forward, and then on a set position starts following the player. alt text

1.png (7.6 kB)

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Answer 2

Your question is quite incomplete. Is this a closed door, that your enemy has to open and come out of it? Or it is just an open doorway?

Theare a few ways to handle it. The most easiest, I suppose, is to set up your navigaition walkable areas, if it is not yet set, to prevent the enemy from walking through walls. (There are great unity tutorials on this topic).

If you door is closed and you want it to open, simly when the enemy comes in range with it, just set up trigger collider and when enemy comes in range with it just open it.

Hope this helped.

Edit: Wrote a short example of how to do it manually. It's kinda hardcodede but well, here it is:

So you will need atleast three objects: Player, Enemy, Door with tags set to each other corresponding to tags in code. Enemy should have a rigidbody for collision detection purposes. Door should have a child object placed after the door(point where the enemy will move to pass the door). Also you have to put a trigger collider before the door to trigger the behaviour.

Script you put on Enemy:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Enemy : MonoBehaviour {
 
     private Transform followTarget;//target we are currently folowing
     private bool isFollowing;//shows if we are following or not atm
     
     [SerializeField]private float speed = 2f;//speed of the enemy
     [SerializeField]private float doorOpenTime = 2f;//time when enemy stands still while door opens
 
 
     void Start() {
         followTarget = GameObject.FindGameObjectWithTag("Door").transform;//we store the door transform as our followTarget
         isFollowing = true;//start following
     }
 
     void Update() {
         if (isFollowing) {
             transform.position = Vector3.MoveTowards(transform.position, followTarget.position, speed * Time.deltaTime);//if we enemy is currently following something it move to it gradually
         }
     }
 
     public void WaitForDoorOpen() {
         isFollowing = false;//stop following
         Invoke("PassThroughDoor", doorOpenTime);//resume following when door animation ends
     }
 
     void PassThroughDoor() {
         followTarget = followTarget.GetChild(0).transform;//we get the point after the door which is a child object of the door
         isFollowing = true;//start following
         Invoke("StartFollowingPlayer", 4f);//after some time after we pass the door we start folowing player
     }
 
     void StartFollowingPlayer() {
         followTarget = GameObject.FindGameObjectWithTag("Player").transform;//store player transform as our follow target
     }
 
 }

And the code we put on the door:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Door : MonoBehaviour {
 
     void OnTriggerEnter(Collider other) {
         if (other.tag == "Enemy") {//if the collider entered the trigger has tag enemy
             other.GetComponent<Enemy>().WaitForDoorOpen();//run the function
         }
     }
 }

Object moving forward before it starts functioning

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