Rotate cameran around a gameobject in unity3d

Question

I want to rotate camera around an fbx object when a key is being pressed using unity 3d.How it do? I tried some examples but its not working. First i create a game object and add main camera child of it.

Answer 1

public class CameraOrbit : MonoBehaviour
{
  public Transform target;
  public float speed = 1f;
  private float distance;
  private float currentAngle = 0;

  void Start()
  {
      distance = (new Vector3(transform.position.x, 0, transform.position.z)).magnitude;
  }

  void Update()
  {
      currentAngle += Input.GetAxis("Horizontal") * speed * Time.deltaTime;

      Quaternion q = Quaternion.Euler(0, currentAngle, 0);
      Vector3 direction = q * Vector3.forward;
      transform.position = target.position - direction * distance + new Vector3(0, transform.position.y, 0);

      transform.LookAt(target.position);
  }
}

I dont have access to unity at the moment so i might have messed something up.

The idea is keep an angle that you change based on input. Create a Quaternion from the angle (the Quaternion say how to rotate a vector to a certain direction), then rotate a Vector to that direction. Starting from the targets position move in that direction a certain distance and then look at the targets position.

This only implements rotation around the y axis, if you want rotation around the x axis all you need is another angle variable and then change to this Quaternion.Euler(currentAngleX, currentAngleY, 0);