Resolved Rotate to the target (Canvas indicator)

Hello. I use in a project a system which shows as Damage Indicator where are my enemies according my position. All works as expected, but there is a little problem because of an important feature - my spaceship uses a 6dof controller (like in Forsaken, Descent or OverLoad games). So it can rotate on each axis - and this way sometimes its head (main camera) is upside/down. Then Damage Indicators are inverted in my UI. I am trying to fix this problem adding a correction, but quaternions are so confusing for me. I use this function to display Damage Indicator, but it is efficient only for a simple FPS controller, not for a 6dof controller :

Code (CSharp):

1.  
2. IEnumerator RotateToTheTarget()
3. {
4.     while (enabled)
5.     {
6.         if (Target)
7.         {
8.             tPos = Target.position;
9.             tRot = Target.rotation;
10.         }
11.  
12.         Vector3 direction = (player.position - tPos).normalized;
13.  
14.         tRot = Quaternion.LookRotation(direction);
15.         tRot.z = -tRot.y;
16.         tRot.x = 0;
17.         tRot.y = 0;
18.  
19.         Vector3 northDirection = new Vector3(0, 0, player.eulerAngles.y);
20.         GetComponent<RectTransform>().localRotation = tRot * Quaternion.Euler(northDirection);
21.  
22.         yield return null;
23.     }
24. }
25.  

On the first picture, the indicator works as expected :

On the second, my ship is upside/down and indicator is inverted :


There is something wrong with my NorthDirection definition. My Damage Indicator UI rotates correctly in a circle using an anchor, but when my ship is upside/down, all Damage Indicators are inverted. I guess that I should change something, but I tried many variants - it's worst. Have you an idea? Thank you for your help. Sorry for my poor English ++

 

Hello. I have another idea. Is there a way to translate WorldToScreenPoint to radians - an indicator similar with a clockwise. This way an object in up/left in my camera has for radian ~=300 and down/right ~=120. I have the canvas UI, but I need a way so as to compute WorldToScreenPoint to radians. Thank you ++

 

Hello. Finally I found a good solution. I totally changed my code for something more logical. I had some difficulties so that I understand some important things like difference between Vector3.forward and transform.forward. In the code below, I don't use Vector3.Angle because it is always relative. I hope that it could help someone ++

Code (CSharp):

1. public static float AngleSigned(Vector3 v1, Vector3 v2, Vector3 n)
2. {
3.      return Mathf.Atan2(Vector3.Dot(n, Vector3.Cross(v1, v2)), Vector3.Dot(v1, v2)) * Mathf.Rad2Deg;
4. }
5.  
6. IEnumerator RotateToTheTarget()
7. {
8.     while (enabled)
9.     {      
10.         Vector3 direction = (player.position - tPos).normalized;
11.         Vector3 correction = new Vector3(0, 0, -AngleSigned(player.forward, direction, player.up));
12.  
13.         GetComponent<RectTransform>().localRotation = Quaternion.Euler(correction);
14.  
15.         yield return null;
16.     }
17. }

 

Glad to see that you've successfully resolved this problem.
Could you show me the damage indicator function in-game?
Using gif or something?
Could you also explain this line of code:

Vector3 direction = (player.position - tPos).normalized;

        Vector3 correction = new Vector3(0, 0, -AngleSigned(player.forward, direction, player.up));

What is tPos here?
I'm also having some problem in making of damage indicator. It does work but doesnt show correct position of damage.
Looking forward for your reply.