无法将类型“float”隐式转换为“UnityEngine.Quaternion”

Question

I am working on a 2D game, but I need to be able to shoot in the direction of the mouse, so I am trying to set the rotation of an empty to point towards the mouse so that the projectile can shoot from the empty because I don't want the character to rotate, but I get an error on the last line "Cannot implicitly convert type 'float' to 'UnityEngine.Quaternion'" How do I fix this? I can't use a Rigidbody 2D because the empty is parented and inside of a player with a RidgidBody2D and collider. If there is a better way to do this (which there probably is), let me know. Sorry if this is a dumb question, I am new to Unity and C#.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Point_and_Shoot : MonoBehaviour
{
    public Camera cam;
    public Rigidbody2D rb; //Ridgidbody of player
    public Transform rb2; //Transform of empty (empty is at same position as player but it's parented so I have to take position from player because the position is relative to the parent)
    Vector2 mousePos;

    void Update()
    {
        mousePos = cam.ScreenToWorldPoint(Input.mousePosition);
    }
    void FixedUpdate()
    {
        Vector2 lookDir = mousePos - rb.position;
        float angle = Mathf.Atan2(lookDir.y, lookDir.x) * Mathf.Rad2Deg - 90f;
        rb2.rotation = angle; //<-- The error is here
    }
}

Answer 1

something like this would work

    float angle = Mathf.Atan2(1, 2) * Mathf.Rad2Deg - 90f;
    rb2.rotation = new Quaternion(angle, 0, 0, 0);

Instead of setting the rotation to a single value, you can use the constructor Quaternion . You enter four values. The first three being the x, y, and z. The fourth isn't needed in this case. Only type Quaternion works here . You can't use Vector3, or Vector2. You can move the angle variable to y or z places because you might not want to rotate the way it was written above. A link

read up on the type system

https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/types/

this is a good explination

Answer 2

Quaternion represents the rotation for the whole object, not just an angle. Try to set eulerAngles directly, since it accepts angles as floats (Vector3). If you want to have a 90° rotation around the Z axis, it would look something like this:

eulerAngles = new Vector3(0, 0, 90); // Create/set euler angles in degrees.

quaternion.eulerAngles = eulerAngles; // Apply set euler angles to our quaternion

transform.rotation = quaternion; // Apply quaternion to our game object/transform

If you want to create some kind of continuous (rotation) motion, you should keep Time.Delta time in mind as a factor.

Answer 3

Your "angle" variable is of a float data type. This cannot be assigned to Quaternion, as Quaternion calls for 4 values (float is just assigning 1). Alternatively, you could do this:

public Quaternion rb2.rotation;

and then assign the angle into quaternion in the form (angle, value, value, value)