ontriggerenter does not update my score variable in gamemanager

Hello!

I have a bullet that triggers a score increase when it hits an enemy. But I can't figure out for the life of me why it's not working. The score (5) on the bullet triggers once, but whenever I hit enemies after that the score no longer increases. The debug stays at 5. The trigger works though because the enemy is destroyed:

Bullet script (attached to gameobject that is spawned from the player):

Code (CSharp):

1.  
2. public class Bullet : MonoBehaviour
3. {
4.     int score;
5.  
6.     void Start() {
7.         score = GameObject.Find("GameManager").GetComponent<GameManager>().score;
8.     }
9.  
10.     public void OnTriggerEnter(Collider other)
11.     {
12.         if(other.gameObject.CompareTag("Enemy"))
13.         {
14.             score += 5;
15.             Debug.Log("hit: " + score);
16.             Destroy(other.gameObject);
17.             Destroy(gameObject);
18.         }
19.     }
20. }
21.  

The gamemanager script is attached to a GameManager object in the scene:

Code (CSharp):

1.  
2. public class GameManager : MonoBehaviour
3. {
4.     private int m_score;
5.     public int score {
6.         get { return m_score; }
7.         set { m_score = score; }
8.     }
9.     [SerializeField] private List<GameObject> m_enemyList = new List<GameObject>();
10.     public List<GameObject> enemyList {
11.         get { return m_enemyList; }
12.     }
13.  
14.     void Start()
15.     {
16.         InvokeRepeating("SpawnRandomEnemy", 1, 2);
17.     }
18.  
19.     // randomise the spawned enemy
20.     public void SpawnRandomEnemy()
21.     {
22.         int randomEnemy = Random.Range(0, enemyList.Count);
23.         SpawnEnemy(enemyList[randomEnemy]);
24.     }
25.  
26.     // spawn an enemy
27.     public static void SpawnEnemy(GameObject enemyType)
28.     {
29.         Vector3 spawnPos;
30.         spawnPos = new Vector3(0, 0, -35f);
31.         Instantiate(enemyType, spawnPos, enemyType.transform.rotation);
32.     }
33. }
34.  

I can't work out what I'm doing wrong, from following various threads and posts in different forums/websites I just can't figure it out?

 

@melv

Yeh you're right, I think my thought process is wrong with this. I'm thinking that the score has to increase when the bullet detects that it has hit an enemy. Like you said I'm assuming I can just bring in the score value and update it within bullet. Should I be running a method within GameManager instead, which increases the score? I don't have to do it the way I have coded. I just want to tell the GameManager to increase the score, when a bullet detects that it's hit an enemy. I think that's where I'm stuck. I'm still a noob and learning

I've tried this but I'm still getting the same response, unless I'm misunderstanding what I'm supposed to do?

Code (CSharp):

1. public class Bullet : MonoBehaviour
2. {
3.     GameManager gameManager;
4.  
5.     void Start() {
6.         gameManager = GameObject.Find("GameManager").GetComponent<GameManager>();
7.     }
8.  
9.     public void OnTriggerEnter(Collider other)
10.     {
11.         if(other.gameObject.CompareTag("Enemy"))
12.         {
13.             gameManager.score += 5;
14.             Debug.Log("hit: " + gameManager.score);
15.             Destroy(other.gameObject);
16.             Destroy(gameObject);
17.         }
18.     }
19. }

 

Thanks for your help, I'll give that a shot and see how I go. Pun intended

 

So I made a few tweaks, I was hoping I got it right but my score is still stuck at zero:

Moved the trigger to the enemy script:

Code (CSharp):

1. public class Enemy : MonoBehaviour
2. {
3.     GameManager gameManager;
4.  
5.     void Start() {
6.         gameManager = GameObject.Find("GameManager").GetComponent<GameManager>();
7.     }
8.  
9.     public void OnTriggerEnter(Collider other)
10.     {
11.         if (other.gameObject.CompareTag("Boundary"))
12.         {
13.             Destroy(this.gameObject);
14.         }
15.  
16.         if(other.gameObject.CompareTag("Bullet"))
17.         {
18.             gameManager.AddScore(5);
19.             Destroy(this.gameObject);
20.             Destroy(other.gameObject);
21.         }
22.     }
23. }

Added a method to GameManager to increase the score:

Code (CSharp):

1. public class GameManager : MonoBehaviour
2. {
3.     private int m_score;
4.     public int score {
5.         get { return m_score; }
6.         set { m_score += score; }
7.     }
8.  
9.     public void AddScore(int addPoints)
10.     {
11.         this.score += addPoints;
12.         Debug.Log("Score:" + this.score);
13.     }
14. }

Another thing I have are child scripts on the enemies which inherit the enemy class above. The Enemy script itself is not attached to anything. Not sure if this would affect anything. I would think not as the trigger does appear to be working.

 

Since you have a public method that modifies your score, just have it change the value of m_score directly. Your method can handle any conditionals that are needed. Get rid of the property. Just have your AddScore method += to m_score and then debug m_score.

Also, you may want to look into manager or singleton setups in the future for classes such as GameManager, as it will remove the need to do your GameObject.Find. Or, take the advice given of just letting the GameManager assign itself on the enemy when it instantiates an enemy.

 

Thanks, I did look at this, but I didn't quite understand what it was I needed to do. I have removed the property for the score though, so I'm getting the score back correctly now! I originally made it into a property to help me understand how they work, I guess I don't quite yet!

Singletons are on my todo list, for sure!

 

Hello. I'm having the same problem as ArisenShard. When I kill some zombie in my game, my "OnTriggerEnter" is called, adding some points to my variable, as you can see below:

Code (CSharp):

1.    
2.  
3. using System;
4. using System.Collections;
5. using System.Collections.Generic;
6. using UnityEngine;
7. using UnityEngine.SocialPlatforms.Impl;
8. using UnityEngine.UI;
9.  
10.  
11. public class DetectCollisions : MonoBehaviour
12. {
13.     public int score;
14.  
15.     void OnTriggerEnter(Collider other)
16.     {
17.         Destroy(gameObject);
18.         Destroy(other.gameObject);
19.         if (other.gameObject.CompareTag("Zombie"))
20.         {
21.             Debug.Log("Score " + score);
22.             score++;
23.         }
24.         Debug.Log("Score: " + score);
25.     }
26. }

I know the function is being called because it appears in the log in Unity. In Debuging mode, I see the function is being called twice and on the second call, it resets my score. Someone can help me?

 

Probably not. If you had then the fix would have worked for you too.

Please don't necro post. When you have an issue, make a new post... it's FREE!

When you post, how to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

This is the bare minimum of information to report:

- what you want
- what you tried
- what you expected to happen
- what actually happened, especially any errors you see
- links to documentation you used to cross-check your work (CRITICAL!!!)

If you have no idea what code is running where or when, time to do some more debugging.

The first question I would ask is "Why does the detect collisions script have a score?" See above.

Time to start debugging! Here is how you can begin your exciting new debugging adventures:

You must find a way to get the information you need in order to reason about what the problem is.

Once you understand what the problem is, you may begin to reason about a solution to the problem.

What is often happening in these cases is one of the following:

- the code you think is executing is not actually executing at all
- the code is executing far EARLIER or LATER than you think
- the code is executing far LESS OFTEN than you think
- the code is executing far MORE OFTEN than you think
- the code is executing on another GameObject than you think it is
- you're getting an error or warning and you haven't noticed it in the console window

To help gain more insight into your problem, I recommend liberally sprinkling

Debug.Log()

statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

- is this code even running? which parts are running? how often does it run? what order does it run in?
- what are the names of the GameObjects or Components involved?
- what are the values of the variables involved? Are they initialized? Are the values reasonable?
- are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as

Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer or iOS: https://forum.unity.com/threads/how-to-capturing-device-logs-on-ios.529920/ or this answer for Android: https://forum.unity.com/threads/how-to-capturing-device-logs-on-android.528680/

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

Here's an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

https://forum.unity.com/threads/coroutine-missing-hint-and-error.1103197/#post-7100494

When in doubt, print it out!(tm)

Note: the

print()

function is an alias for Debug.Log() provided by the MonoBehaviour class.

 

Okay, thanks for advise. I will create another topic at the forum