Rigidbody.AddForce doesn't always work

I'm trying to add force to an object when a key is pressed. it works most of the time, but one in every few key presses just doesn't work. I don't think it's a code issue but here it is anyway:

Code (csharp):

1.  
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. public class Bird : MonoBehaviour {
7.  
8. Rigidbody bird;
9. public int force = 10;
10. bool canFlap = true;
11. public float timer = 0.25f;
12.  
13.     // Use this for initialization
14.     void Start () {
15.        
16.         bird = GetComponent<Rigidbody>();
17.     }
18.    
19.     // Update is called once per frame
20.     void FixedUpdate () {
21.        
22.         if(Input.GetButtonDown("Jump") && canFlap == true){
23.            
24.             Wait();
25.             bird.velocity = new Vector3(0,0,0);
26.             bird.AddForce(Vector3.up * force);
27.         }
28.     }
29.  
30.     IEnumerator Wait () {
31.        
32.         canFlap = false;
33.         yield return new WaitForSeconds(timer);
34.         canFlap = true;
35.     }
36. }
37.  

Any ideas? Thanks!

 

I don't know if this is your issue, but from what I understand, you can call coroutines in JavaScript the way you have here

Code (csharp):

1. Wait()

In C#, though, you need to do it this way:

Code (csharp):

1. StartCoroutine("Wait");

It might be messing with the results you expect by not calling it the right way, perhaps.


Actually, found it in the docs..

https://docs.unity3d.com/ScriptReference/MonoBehaviour.StartCoroutine.html

Kind of crummy that this doesn't cause a compiler error since it doesn't really seem to have any purpose to allow that as far as I know..?? (maybe it does, I don't know)

 

It does have a purpose. You can use a coroutine as a default method and execute any code within it without creating an instance of coroutine itself, basically negating yields.

Also @Seppi, make sure you're not creating multiple coroutines with StartCoroutines (unless you want to do it ofc).

Use null checks for either coroutine itself, or the enumerator:

Code (CSharp):

1.  
2. // E.g. pseudocode
3. ...
4. private Coroutine _coroutine;
5.  
6. private void FixedUpdate(){
7. ...
8.    if (_coroutine != null){
9.        StopCoroutine(_coroutine);
10.        _coroutine = null;
11.    }
12.    _coroutine = StartCoroutine(YourCoroutine());
13. ...
14. }
15.  
16. // Or enumerator
17. private IEnumerator _coroutineEnumerator;
18.  
19. ...
20.     if (_coroutineEnumerator != null){
21.          StopCoroutine(_coroutineEnumerator);
22.          _coroutineEnumerator = null;
23.     }
24.     _coroutineEnumerator = Coroutine;
25.    StartCoroutine(_coroutineEnumerator);
26. ...

 

Oh really... Yesterday I had quickly tried that before posting to make sure, and it didn't seem to call the function at all. I must have something wrong though. Anyways, not sure the issue outside of that.

Edit:, I don't think it's true that just calling it as Wait() calls it like a regular function, unless I misunderstood:

Code (csharp):

1.  
2. public class test : MonoBehaviour
3. {
4.     void Start ()
5.     {
6.         Debug.Log("Before wait");
7.         Wait();
8.         Debug.Log("After wait");
9.     }
10.  
11.     IEnumerator Wait()
12.     {
13.  
14.         Debug.Log("Start");
15.         yield return new WaitForSeconds(2.0f);
16.         Debug.Log("End");
17.     }
18. }

Console output:

Code (csharp):

1.  
2. Before wait
3. UnityEngine.Debug:Log(Object)
4. test:Start() (at Assets/test.cs:14)
5.  
6. After wait
7. UnityEngine.Debug:Log(Object)
8. test:Start() (at Assets/test.cs:16)
9.  

Note that the "Start" and "End" doesn't show in the log at all, telling me that Wait isn't even called here.