Help with rotation based off axes.

Unity Engine
1

Hi! I’m super new to Unity and programming in general, and am trying to learn as I go.

I’m trying to make a sprite turn with my input directions, like when I move left using “a”, the sprite points left, and I would like to do it so there are 8 directions (North, northeast, east, southeast, etc.) based off the input.

I tried using Quaternion.Lerp in order to set the rotation and it works. I don’t want to make 8 “if” statements just to figure out where I want to point, so I’m wondering if there’s a better way to use Input.GetAxis data from Vertical and Horizontal and figure out where to point. Hopefully this makes sense.

2

I believe this is all you need to set your sprite’s X axis to the input direction:

Vector2 input = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));

transform.right = input;
3

What if i want to Lerp it?

4

Wait, i dont want to move the sprite, I want to rotate it…

5

That code will set the orientation of the transform, it won’t move it. It’s just saying “point the transform’s X axis in this direction”.

You could linearly interpolate it, but for a rotation you probably want a spherical interpolation.

Here’s a bit more complicated version that uses rotations:

public float turnSpeed = 5f;

private void Update()
{
    Vector2 input = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));

    // we want to point the X axis in the input direction
    Vector3 xAxisDirection = input.normalized;

    // the Y axis will be 90 degrees away from the X axis
    Vector3 yAxisDirection = Quaternion.Euler(0,0,90) * xAxisDirection; 

    // the Z axis points forward in 2D
    Vector3 zAxisDirection = Vector3.forward;

    // this function takes Z axis and Y axis, and gives back the rotation for that orientation
    Quaternion newRotation = Quaternion.LookRotation(zAxisDirection, yAxisDirection);

    // interpolate rotation over time
    transform.rotation = Quaternion.RotateTowards(transform.rotation, newRotation, turnSpeed * Time.deltaTime);
}