Coroutine Won't Yield

Pulling my hair out about this one. I have this code inside of a coroutine...

Code (CSharp):

1. Vector3 flatFwd = new Vector3(my_transform.forward.x, 0, my_transform.forward.z);
2. Quaternion fwdRotation = Quaternion.LookRotation(flatFwd, Vector3.up);
3. float angle = Quaternion.Angle(my_transform.rotation, fwdRotation);
4. Debug.Log (angle);
5. while(angle > 1.0f)
6. {
7.    my_transform.rotation = Quaternion.Slerp(my_transform.rotation, fwdRotation, Time.deltaTime * 2.0f);
8.    angle = Quaternion.Angle(my_transform.rotation, fwdRotation);
9.    yield return null;
10. }

...but it won't yield there. It just goes right through it. What am I over-looking?

 

Are you calling your coroutine with StartCoroutine?

 

Yep. Here's the majority of the code.

Code (CSharp):

1.  
2.     private IEnumerator Capture(Collision col)
3.     {
4.         yield return StartCoroutine(Move(col));
5.         rigidbody.WakeUp();
6.         while(distance_to_ground > 0.2f)
7.         {
8.             yield return null;
9.         }
10.         rigidbody.isKinematic = true;
11.         yield return StartCoroutine(Try(col));
12.     }
13.     private IEnumerator Move(Collision col)
14.     {
15.         Vector3 move_to = new Vector3(transform.position.x-1.5f, col.contacts[0].point.y+1.5f, transform.position.z-1.5f);
16.         while(Vector3.Distance(transform.position, move_to) > 0.01f)
17.         {
18.             rigidbody.velocity = Vector3.zero;
19.             rigidbody.angularVelocity = Vector3.zero;
20.             rigidbody.Sleep();
21.             transform.LookAt(col.transform.position);
22.             transform.position = Vector3.Lerp(transform.position, move_to, 5f * Time.deltaTime);
23.             yield return null;
24.         }
25.         animation["Open_Top"].speed = 5;
26.         animation.Play("Open_Top");
27.         GameObject orb = Instantiate(capture_orb_prefab, col.gameObject.GetComponentInChildren<Renderer>().renderer.bounds.center, Quaternion.identity) as GameObject;
28.         col.gameObject.SetActive(false);
29.         while(Vector3.Distance(my_transform.position, orb.transform.position) > 0.01f)
30.         {
31.             Vector3 orb_target = new Vector3(my_transform.position.x, my_transform.position.y, my_transform.position.z);
32.             orb.transform.position = Vector3.Lerp(orb.transform.position, orb_target, 2.7f * Time.deltaTime);
33.             yield return null;
34.         }
35.         orb.transform.parent = my_transform;
36.         animation["Close_Top"].speed = -5f;
37.         animation["Close_Top"].time = animation["Close_Top"].length;
38.         animation.Play("Close_Top");
39.         Vector3 flatFwd = new Vector3(my_transform.forward.x, 0, my_transform.forward.z);
40.         Quaternion fwdRotation = Quaternion.LookRotation(flatFwd, Vector3.up);
41.         float angle = Quaternion.Angle(my_transform.rotation, fwdRotation);
42.         while(angle > 1.0f)
43.         {
44.             my_transform.rotation = Quaternion.Slerp(my_transform.rotation, fwdRotation, Time.deltaTime * 2.0f);
45.             angle = Quaternion.Angle(my_transform.rotation, fwdRotation);
46.             yield return null;
47.         }
48.         Destroy(orb);
49.     }

 

Whats the value of angle before the while loop ?
If its > 1 in the begining, then you can print the values
of angle within the while loop because I can see
no other reason for the while loop to go false.
I think you would've tried these already though.

 

I did... I Debug.Log'd the value of angle...and it comes out to 44._ _ _ .

 

So the while loop doesn't execute even once ? I mean, what values of
angle do you get when you debug.log(angle) inside the loop ?

 

Haven't tried it inside the loop...but I would think I shouldn't even need to. Give then fact that as soon as the loop starts angle is already > 1.

 

You never know..because I fail to see any other reason why the while loop will not execute !

 

Alright. I just debugged it inside the while loop...the while loop IS executing, but so is everything else after it.

 

aah ok...So the while loop yields and while it is yielding, it executes the part
after the loop too simultaneously ?
Sometimes such are the issues that make me wanna take a new birth

 

Exactly! It's like Untiy decided to say, "I don't care about THAT yield statement, I'm going to keep going."

 

Hmm..
I'm sure you must've
Debug.log after that dreaded while loop to make sure that it is what is executing.
I ask this because maybe that orb is getting destroyed elsewhere.

 

oh yaa I just noticed that in line 35 you have orb.transform.parent= my_transform;
which means it is changing its parent. Maybe this is why it appears to get
destroyed while actually it is moving to a different parent.

 

Nah...that's not it. Even commenting out that line, still causes it to continue on past the while loop. During runtime I can see this happen frame by frame because

Code (CSharp):

1.     private IEnumerator Capture(Collision col)
2.     {
3.         yield return StartCoroutine(Move(col));
4.         rigidbody.WakeUp(); // THIS LINE SHOULDN'T HAPPEN UNTIL THE WHILE LOOP IS
5.                              //COMPLETE & THE ORB IS DESTROYED
6.         while(distance_to_ground > 0.2f)
7.         {
8.             yield return null;
9.         }
10.         rigidbody.isKinematic = true;
11.         yield return StartCoroutine(Try(col));
12.     }

...during runtime I play it forward frame by frame, and before the rotation is done adjusting itself, the rigidbody is already falling to the ground.

 

Seems like you've got some misunderstandings about how this is all being processed, to me...

To clarify, are you thinking that doing yield return StartCoroutine() is going to pause execution until the coroutine has completed? Because it won't.

 

Yes it will. Unity has an example of it here, and I use it very often.

 

This is what happens when I wake up at 3 am and try to answer questions on my phone...

 

Hmmm...which makes my scenario even more mind boggling (to me).

 

hmm strange..is it possible to extract out a test project with the problematic stuff
and upload a zip here ?

 

I figured it out...

Code (CSharp):

1.     Vector3 move_to = new Vector3(transform.position.x-1.5f, col.contacts[0].point.y+1.5f, transform.position.z-1.5f);
2.     while(Vector3.Distance(transform.position, move_to) > 0.01f)
3.     {
4.         rigidbody.velocity = Vector3.zero;
5.         rigidbody.angularVelocity = Vector3.zero;
6.         rigidbody.Sleep();
7.         transform.LookAt(col.transform.position);
8.         transform.position = Vector3.Lerp(transform.position, move_to, 5f * Time.deltaTime);
9.         yield return null;
10.     }

This while loop was causing the rigidbody to wake up and go to sleep everytime it looped. On its final iteration, the rigidbody was still awake, which caused the ball to drop before it should. Changed it to...

Code (CSharp):

1.   rigidbody.velocity = Vector3.zero;
2.   rigidbody.angularVelocity = Vector3.zero;
3.   rigidbody.Sleep();
4.   Vector3 move_to = new Vector3(transform.position.x-1.5f, col.contacts[0].point.y+1.5f, transform.position.z-1.5f);
5.   while(Vector3.Distance(transform.position, move_to) > 0.01f)
6.   {
7.    transform.LookAt(col.transform.position);
8.    transform.position = Vector3.Lerp(transform.position, move_to, 5f * Time.deltaTime);
9.    yield return null;
10.   }

Works flawlessly now.

 

damn I had exactly thought earlier that the Sleep() is causing the issue but
its good to know you fixed it..I know the feeling when a hard to trace issue
is fixed