Player rotation issues (Player returns to default forward rotation after releasing keys)

Question

So basically what is happening is that my player rotates and faces the direction that he is currently being steered toward (which is wonderful). But after I release, let's say the A key, meaning he is currently facing and moving to the left, he goes back to facing forward after the key is released.

Here is my code:

public class PlayerMovement : MonoBehaviour {
public bool isGrounded;
private float distToGround;
private Vector3 v;
private Vector3 h;
public float speed;

Rigidbody rb;
Collider col;

void Start() {
    rb = GetComponent<Rigidbody>();
    col = GetComponent<Collider>();
    distToGround = col.bounds.extents.y;
}

void Update() {
    if (Physics.Raycast (transform.position, -Vector3.up, distToGround + 0.1f)) isGrounded = true; else isGrounded = false;
    if (isGrounded) {
        v = new Vector3(0, 0, Input.GetAxis("Vertical")) * speed;
        h = new Vector3(Input.GetAxis("Horizontal"), 0, 0) * speed;
        rb.MovePosition(rb.position + v * Time.deltaTime);
        rb.MovePosition(rb.position + h * Time.deltaTime);

//This deals with all the rotation
        Vector3 direction = new Vector3( Input.GetAxis ("Horizontal"), 0, Input.GetAxis ("Vertical") );
        Quaternion rotation = Quaternion.LookRotation(direction, Vector3.up);
        transform.rotation = rotation;
    }
  }
}

I obviously know that the reason this is happening is because the rotation is being set to the axis currently being pressed, so when I release any key, the rotation goes back to the original position. I just can't quite figure out how to fix it...

Answer 1

I think the issue is that the input is being polled every frame as part of the Update().

I would suggest pulling the input from the Update() and using input callbacks instead. That way the input is only polled when fired, and not every frame. That should cause the direction to only update with input changes, and the Update() will continue to render the same direction until the value is changed the next time the callback fires.

Unity doesn't have callbacks, I forgot that I emulate them. This is going to take some more thought on my part. I will update soon.

If your game is a top down on an 8 point compass this gets a lot easier, but I'm trying to come up with a generalized solution.

Answer 2

Try adding an if statement saying if neither of the axis are equal to zero then change the rotation, this would eliminate facing forwards when there is 0 on each axis.

if(direction != Vector3.zero)
{Quaternion rotation = Quaternion.LookRotation(direction, Vector3.up);
    transform.rotation = rotation;
}

Hope this helped.

Here is another solution on Velocity;

    if (direction != Vector3.zero)
    {
        transform.rotation = Quaternion.LookRotation(direction);  
    }

Hope this is better.