Question How can I make the placed model always face the camera?

Hi, I want to place my model and always face to the camera of the phone. I tried to calculate the angle between the camera and the placed object in the x and z axis and then according to this angle I want to rotate my object in the y axis but I didn't get correct results from that process. I tried to figure out that which angle should I use but none of them seemed correct to me.

Code (CSharp):

1. if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began)
2. {
3.    if (m_RaycastManager.Raycast(Input.GetTouch(0).position, s_Hits, TrackableType.PlaneWithinPolygon))
4.    {
5.        var firstHit = s_Hits[0];
6.        var camPosition = Camera.main.transform.position;
7.  
8.        //I tried to calculate angles
9.        var angleHitRelativePoseToCam = Mathf.Atan2(firstHit.sessionRelativePose.position.z-camPosition.z, firstHit.sessionRelativePose.position.x-camPosition.x) * Mathf.Rad2Deg;
10.  
11.        var angleHitRelativePoseTo0 = Mathf.Atan2(firstHit.sessionRelativePose.position.z-0, firstHit.sessionRelativePose.position.x-0) * Mathf.Rad2Deg;
12.  
13.        var angleHitPoseTo0 = Mathf.Atan2(firstHit.pose.position.z-0, firstHit.pose.position.x-0) * Mathf.Rad2Deg;
14.  
15.        var angleHitPoseToCam = Mathf.Atan2(firstHit.pose.position.z-camPosition.z, firstHit.pose.position.x-camPosition.x) * Mathf.Rad2Deg;
16.  
17.       modelContent.transform.rotation = Quaternion.AngleAxis(angle, Vector3.up);
18.       m_SessionOrigin.MakeContentAppearAt(modelContent, firstHit.pose.position);
19.  
20.       //one of the attepms
21.       m_SessionOrigin.MakeContentAppearAt(modelContent, firstHit.pose.position, m_Rotation); //0 0 0
22.  

Then I tried to use

transform.LookAt()

method between object, camera and sessionOrigin.

modelContent.transform.LookAt(m_SessionOrigin.transform);

At the end I didn't achieve any result from those tries.

So any help would be much appreciated!! Thanks

 

Thank you for your reply, I also tried this approach but It is rotating my model on X and Z axis, I just want to rotate it on Y axis. I tried to get Y rotation value and set it to the model as new Y rotation from the

LookAt()

method but this also didn't work for me. I think there is relative coordinate system issue that I can't find correct inputs for my problem. I mean my placed object could has plane related coordinates and my camera gives me another coordinate space input and I can't calculate correct angle.