Unity C# - Rotate smoothly an object towards the direction given by input

Question

I am trying to rotate an object towards the direction given by de direction of the input. For example, if I am pressing 'up' of the directional pad, the player should rotate pointing that direction.

I've tried using Euler angles, and when I press the direction, I call a coroutine that sums the eulerAngle.y of the object till it gets the angle of the direction, but it doesn't work. I don't know if there is another approach to use.

Here is the code for the coroutine. It starts if a certain key is pressed and if a flag is not activated:

 IEnumerator rotateTowards(float angle)
 {
    rotating = true;
    Debug.Log("Rotating the mono...");
    Debug.Log("Your angle: " +transform.eulerAngles.y);
    float turningTime = 0.8f;
    //float thisAngle = this.transform.eulerAngles.y;
    Vector3 thisAngle = this.transform.eulerAngles;

    if(thisAngle.y < angle)
    {
        while(thisAngle.y < angle)
        {
            thisAngle.y += turningTime * Time.deltaTime;
            this.transform.eulerAngles = thisAngle;
        }
    }

    if(thisAngle.y > angle)
    {
        while(thisAngle.y > angle)
        {
            thisAngle.y -= turningTime * Time.deltaTime;
            this.transform.eulerAngles = thisAngle;
        }
    }

    this.transform.eulerAngles = thisAngle;
    rotating = false;
    yield return null;
 }

Thanks in advance.

Answer 1

I don't see why you need a coroutine; I think you need Quaternion.Slerp().

Unity give an example of what you want to do in its documentation.

Answer 2

Have you tried using Debug.Log statements in your code to make sure that your code is even running? Try putting a while(true) statement and then stopping the coroutine when it's done?

Answer 3

First, euler angles aren't precise, everything gets internal converted to quaternions, second Unity has some smoothing on the default input controls, third, u may know but i dont see it in your example, you need to sue StartCouroutine("Name"); to use an IEnumerator.

Ill give you an example of the simplest solution i found

Update(){
    float h=Input.GetAxis("Horizontal");//thies work with WASD or arrow keys + other things unity can use, gamepad etc..
    float v=Input.GetAxis("Vertical");
    if(v!=0||h!=0){// if we are getting inputs, form -1 to 1, 0=no input
        Vector3 direction=(Vector3.forward*h)+(Vector3.right*v);// as the key is held down the h or v values will move toward full -1 or 1, thus handling the smooth rotation
        transform.rotation=Quaternion.LookRotation(direction);
    }
}