Bug Unity3D particle system not updating with character rotation

Here's a gif of the problem I'm having:


The flame is set as a child of the flamethrower's muzzle and I have it set to simulate in world space, however it seems it doesn't update with the bone rotation of the player? Is this a bug?

 

I don't think there are such bugs.
Did you parent a sphere to the bone of your muzzle to check & see if it follows the muzzle mesh?

 

Thank you for responding! I really do appreciate it!

I found a thread here where the op was having the exact same issue for the exact same reason. His solution wasn't a solution however, but more a workaround... He highlighted that the particle system follows the root bone transform, but not any children, which is exactly what I'm seeing as well...

Here is another gif where I've attached a sphere to the muzzle.

 

@daniel_lochner
That's odd because I tried in my own game and I can't reproduce the issue.
It's in world simulation too.

https://i.imgur.com/wIQyUEY.gifv

I've had weird things happen when the scale of the character/rig is not 1. You could check that out.

You could also try and see if it works with Parent Constraint, although that's just a wild shot but it might give us more information.

 

Ah, that's exactly the issue then! I handle aiming in LateUpdate, but that's only because I need to rotate the spine of the player up and down... Where else could I handle this from?

That's then also why you hadn't seen it in your game! The Particle System Update must be called after the Animator Update.

 

Hmm, I've tried OnAnimatorMove, OnAnimatorIK (with IK pass enabled) and various coroutine implementations, but LateUpdate seems to be the only method which successfully overwrites the animations?

 

That was the solution here, however I was hoping there was a more elegant one.

I wrote a quick general-purpose Follower script which I've attached to the Fire, and then set it to follow the muzzle's transform.

Code (CSharp):

1. public class Follower : MonoBehaviour
2. {
3.     #region Fields
4.     [SerializeField] private Transform follow;
5.  
6.     [Header("Position")]
7.     [SerializeField] private bool followPosition = true;
8.     [SerializeField] private float positionSmoothing = -1f;
9.  
10.     [Header("Rotation")]
11.     [SerializeField] private bool followRotation = true;
12.     [SerializeField] private float rotationSmoothing = -1f;
13.  
14.     private Vector3 offsetPosition;
15.     private Quaternion offsetRotation;
16.     #endregion
17.  
18.     #region Methods
19.     private void Start()
20.     {
21.         SetFollow(follow);
22.     }
23.     private void Update()
24.     {
25.         if (!follow) return;
26.  
27.         if (followPosition)
28.         {
29.             transform.position = (positionSmoothing == -1f) ?
30.                 transform.position = follow.position - offsetPosition :
31.                 Vector3.Lerp(transform.position, follow.position - offsetPosition, Time.deltaTime * positionSmoothing);
32.         }
33.  
34.         if (followRotation)
35.         {
36.             transform.rotation = (rotationSmoothing == -1f) ?
37.                 Quaternion.Euler(follow.rotation.eulerAngles - offsetRotation.eulerAngles) :
38.                 Quaternion.Slerp(transform.rotation, Quaternion.Euler(follow.rotation.eulerAngles - offsetRotation.eulerAngles), Time.deltaTime * rotationSmoothing);
39.         }
40.     }
41.  
42.     public void SetFollow(Transform follow)
43.     {
44.         this.follow = follow;
45.  
46.         offsetPosition = follow.position - transform.position;
47.         offsetRotation = Quaternion.Euler(follow.rotation.eulerAngles - transform.rotation.eulerAngles);
48.     }
49.     #endregion
50. }

Is this something that will be looked into though? I can't imagine using a Follower is the desired solution?

 

Ah okay, thanks for your help. For the meantime can I get your official Unity stamp of approval that this is the way to go?

I can then peacefully move on...

 

Having the same issue today. One of the very popular asset store plugins called Final IK causes this by default. IE all final IK shooting games have this issue. I used your workaround Daniel, thanks!

Might be worth fixing though..

 

Sorry Karl, did you respond to the topic? I got an email update, but maybe you deleted the answer..

 

I found a solution to this by using the UnityEngine.LowLevel API to add a custom update function where I run the IK solving between the animation update and particle system update. It might work for you with some adjustments:
https://gist.github.com/emilianavt/3fdc79a8766ff781b86b0eb06aed5084