Laggy health bar

Health bars are supposed to be positioned above the characters' heads. Here's the script that I'm using:

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UI;
3.  
4. public class HealthBar : MonoBehaviour
5. {
6.     [SerializeField]
7.     private Slider slider;
8.  
9.     [SerializeField]
10.     private Color low;
11.  
12.     [SerializeField]
13.     private Color high;
14.  
15.     [SerializeField]
16.     private Vector3 offset;
17.  
18.     private void Update()
19.     {
20.         slider.transform.position = Camera.main.WorldToScreenPoint(transform.parent.position + offset);
21.     }
22.  
23.     public void SetHealth(float health)
24.     {
25.         slider.gameObject.SetActive(health < 100f);
26.         slider.maxValue = 100f;
27.         slider.value = health;
28.         slider.fillRect.GetComponentInChildren<Image>().color = Color.Lerp(low, high, slider.normalizedValue);
29.     }
30. }
31.  

The hierarchy:


The script is attached to the HealthBar objects.

If a character stands still, a health bar is displayed perfectly fine above his head. But if the character is moving or rotating, the health bar starts misbehaving.



I have no idea why it's not standing still above his head when simply rotating. Maybe it has something to do with the fact that the health bar is parented under the object that's rotating?

Full code if needed: https://github.com/kostic017/ZombieShooter

 

Exactly what you hypothesise, your body is rotating equally as fast as your update is running, I expect that to cause some problems. As such, just separate the two and you should be all good.

 

Unparent the health bar or use the LateUpdate function.
Heres a short description of the use of LateUpdate and it seems perfect for your case.

 

Unfortunately, I had to do both for the smoothest experience.

 

If this annoys you you could still keep the game objects organized!
I'd do this by creating an empty gameobject named "Healthbars".
When creating a health bar use Healthbars as parent.

It's up to you how you wanna delete the health bar when the user is destroyed.
I'd suggest listening to MonoBehaviour.OnDestroy on the player & subsequently destroy the health bar using a reference to the gameObject.