Rotate smoothly on sphere

Archived Forums Questions & Answers
1

Hi,
I try to rotate my player on the y-axis smoothly when I turn left(y=-45) or right(y=45) and it feels like I’ve tried all the examples but my player just starts spinning. I guess one of the problems is that my player is moving constantly on a globe (sphere) and the rotation is constantly changing?

The closest I got is this but when I turn left it rotates the wrong way:

    protected Vector3 leftRot = new Vector3(0, -45, 0);
    protected Vector3 rightRot = new Vector3(0, 45, 0);
    protected Vector3 normalRot= new Vector3(0, 0, 0);

  void Update()
    {
        currentRotation = RendererGO.transform.localEulerAngles;
        float LeftRight = 0;
        if (Input.touchCount > 0)
        {
            // touch x position is bigger than half of the screen, moving right
            if (Input.GetTouch(0).position.x > Screen.width / 2)
                LeftRight = 1;
            // touch x position is smaller than half of the screen, moving left
            else if (Input.GetTouch(0).position.x < Screen.width / 2)
                LeftRight = -1;
 }

        moveDir = new Vector3(LeftRight, 0, moveSpeed).normalized;
        //Rotations
        if (LeftRight == -1){
            this.transform.localEulerAngles = Vector3.Lerp(currentRotation, leftRot, Time.deltaTime * rotatesSpeed);
}
        else if (LeftRight == 1){
            this.transform.localEulerAngles = Vector3.Lerp(currentRotation, rightRot, Time.deltaTime * rotatesSpeed);
        }
        else{
            this.transform.localEulerAngles = Vector3.Lerp(currentRotation, normalRot, Time.deltaTime * rotatesSpeed);
        }
    }

I’ve tried som examples that shows Quaternion but I do not succeed… I would love to get some help with this one.

Can you please add the part where you are listening to user input and set the value for leftRot?

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2 Answers

2
2

Thank you @taylank!

The following did the trick:

float angle = Mathf.LerpAngle(RendererGO.transform.localEulerAngles.y, maxAngle, Time.deltaTime * rotatesSpeed);
RendererGO.transform.localEulerAngles = new Vector3(0, angle, 0);

Thanks so much! That really helped. I really appreciate your answer.

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3

When you’re dealing with rotation as vectors, lerp can be difficult to work with due to ambiguity in which direction to lerp in. For instance if you’re at angle 0 and you want to go 30, that’s fine, but if you want to go -30 instead that can be interpreted as 330 and a long lerp from 0 to 330 clockwise.

I’d recommend using Mathf.LerpAngle instead. There is a handy example you can use in the documentation.