Why is this unity camera moving in weird directions?

Question

I have the following script

public class CameraScript : MonoBehaviour {


    public bool AllowZoom;
    public float zoom;
    public float Speed;
    Transform board;
    void Start(){
        board=GameObject.FindGameObjectsWithTag("PlayingBoard")[0].transform;
    }

    void Update(){
       CentreRotate();
    }
    public void arrowMove(){
        if(Input.GetKey(KeyCode.RightArrow)){

            transform.Translate(transform.right*Speed*Time.deltaTime);
        }
        if(Input.GetKey(KeyCode.UpArrow)){
            transform.Translate(transform.up*Speed*Time.deltaTime);
        }
        if(Input.GetKey(KeyCode.LeftArrow)){
            transform.Translate(transform.right*-Speed*Time.deltaTime);
        }
        if(Input.GetKey(KeyCode.DownArrow)){
            transform.Translate(transform.up*-Speed*Time.deltaTime);
        }
    }


    public void CentreRotate(){
        float distance=Mathf.Abs((transform.position-board.position).magnitude);
        float toMove=distance-zoom;
        transform.LookAt(board);
        transform.Translate(transform.forward*toMove);
        arrowMove();
    }
}

This script should allow me to rotate around a given point at a constant distance from the center using the arrow keys. However rather then do that it seems to move towards a spot right above the board and then start turning really fast. It also seems that when slowing down the turning (by dividing distance by a large amount) that the arrow keys give "weird" directions, for example the right arrow key sometimes moves the camera forward.

Anybody got any ideas?

Here are some pictures of what is going on.

On startup:

After I press the right arrow key for a about a second:

Answer 1

You will probably find that what is happening is that the camera object is being rotated by Unity as you translate it. I myself have had this happen where I wanted to rotate around a point, but because the camera was angled down, it would roll as it moved sideways. The best way I found to fix this issue, was to reset the pitch of the camera to look towards the horizon (0), calculate where the camera had to be moved and move it, then pitch the camera down again. You don't have to keep the camera up the whole time the camera's moving though. So: camera x rotation set to 0 translate the camera reset camera rotation

Hopefully, this will fix your problem.