Change item rotation axis in inventory item visualization

Question

I'm learning unity and i'm trying now make an inventory, i made a simple interface, and now i'm trying to make a item visualization. I look for some codes from web and i found this one:

using UnityEngine;

public class TurnObject : MonoBehaviour
{
    protected Vector3 posLastFame;
    public Camera UICam;

    // Update is called once per frame
    void Update()
    {
        if(Input.GetMouseButtonDown(0)) {
            posLastFame = Input.mousePosition;
        }    

        if (Input.GetMouseButton(0)) {
            var delta = Input.mousePosition - posLastFame;
            posLastFame = Input.mousePosition;

            var axis = Quaternion.AngleAxis(-90f, Vector3.forward) * delta;
            transform.rotation = Quaternion.AngleAxis(delta.magnitude * 0.1f, axis) * transform.rotation;
        }
    }
}

I know some code, but I'm not good with geometrics. In this code when I move my mouse horizontal way, my object turn in the Y axis. And that's good. But when I move my mouse vertical the object move in the X axis instead of Z axis.

Is there a way in this code for change this? I really have difficulty to understanding geometrics in Unity.

score 1 · Answer 1 · answered May 29 '20 at 20:02

This line:

var axis = Quaternion.AngleAxis(-90f, Vector3.forward) * delta;

Takes your mouse delta X & Y, and maps them to the world axes -Y and +X, respectively.

To change the mapping to use the Z axis instead of X, just use a different Quaternion, say...

var axis = Quaternion.LookRotation(Vector3.left, Vector3.forward) * delta;

This takes your X & Y to -Y and +Z respectively.

Just beware of creeping roll when you compound these rotations over many frames. For more intuitive controls, you might want to track yaw & pitch angle variables instead.

Change item rotation axis in inventory item visualization

1 Answers1