Gun should point at mouse position

Unity Engine
1

I’m using this code but the rotation is all messed up. How can I get my gun to point wherever my mouse is pointing?

using UnityEngine;
using System.Collections;

public class GunRotate : MonoBehaviour
{
    private void Update()
    {
        Vector3 mousePos = Input.mousePosition;
        transform.LookAt(Camera.main.ScreenToWorldPoint(new Vector3(mousePos.x, Screen.height - mousePos.y, 10.0f)));
        transform.rotation = new Quaternion(0, 90, transform.rotation.z, transform.rotation.w);
    }
}

What I want is the gun’s z axis to be pointing/facing the mouse position so that it’s looking at wherever the mouse position is on the camera. Here’s what I get currently.

2

Quaternions confuse me. Why not just use Euler’s Angle?

3

I don’t have much knowledge about maths, could you please show me how to do it with euler’s angle?

4 
transform.eulerAngles = Vector3(0, 0, degree);

this simply sets the transform’s rotation to degree on the z axis.

5

I tried it but it still not working. The gun doesn’t now rotate around the camera.

6

Well,
In your original code you are affecting the transforms rotation twice. That seems odd. Why not just use one, LookAt or Eulers/quarternion?

7

It would be something like this:

Vector3 mousePos = Input.mousePosition;
Vector3 world_point = Camera.main.ScreenToWorldPoint(new Vector3(mousePos.x, mousePos.y, 10.0f));
transform.LookAt(world_point);

I don’t know why you were doing Screen.height - mousePos.y
Also you are already telling it to look at the point, you don’t need to set the rotation again after that.

This may not work 100% because I just typed this into the Quick Reply box. May have to be slightly tweaked to your liking.

8

About the screen height, I was just playing with some stuff. It doesn’t seem to work either and the result is same as before.

9

try:

Vector3 mousePos = Input.mousePosition;
Vector3 forward = transform.forward * 10f;
Vector3 world_point = Camera.main.ScreenToWorldPoint(new Vector3(mousePos.x, mousePos.y, 0f) + forward);
transform.LookAt(world_point);

I am thinking that its not looking “forward”, so thats why we need to find the forward vector for the transform them increase it (*10) so that it is actually looking at something.

10

Well still same problem. How can you limit axis and just change the z axis?