When rotating 2D sprite towards cursor via angularVelocity, it spins at one point


I’ve created a spaceship sprite in my Unity project, I wanted it to rotate towards the cursor via angular velocity, because I’d like make my game to be heavily physics based.


Now my problem with rotating the sprite via by angular velocity is the following:

At -180° / 180° rotation my ship spins around, because while my mouse’s angle is already 180°, while my ship’s rotation is still -180°, or the other way around.

I tried

I tried to solve it mathematically, wasn’t too successful, I could make it spin the right way just much slower/faster, I could fix the 180/-180 point, but made two different ones instead.

Looked for different solutions, but couldn’t find a more fitting one.


So I have this code for the rotation:

// Use this for initialization
void Start () {
    rb = gameObject.GetComponent<Rigidbody2D>();

// Update is called once per frame
void Update () {
    //getting mouse position in world units
    mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);

    //getting the angle of the ship -> cursor vector
    angle = Mathf.Atan2(mousePos.y - transform.position.y, mousePos.x - transform.position.x) * Mathf.Rad2Deg;

    //getting the angle between the ship -> cursor and the rigidbody.rotation vector
    diffAngle = angle - (rb.rotation + 90);

    //Increasing angular velocity scaling with the diffAngle
    rb.angularVelocity = diffAngle * Time.deltaTime * PlayerShipStats.Instance.speed * 100f;

Inserting this code made it work:

if(diffAngle > 180) {
        diffAngle -= 360;
    } else if (diffAngle < -180) {
        diffAngle += 360;