Vector3.Angle

Parameters

Description

Returns the angle in degrees between from and to.

The angle returned is the unsigned acute angle between the two vectors. This means the smaller of the two possible angles between the two vectors is used. The result is never greater than 180 degrees.

using UnityEngine;

public class AngleExample : MonoBehaviour
{
    public Transform     target;

    // prints "close" if the z-axis of this transform looks
    // almost towards the target

    void Update()
    {
        Vector3 targetDir = target.position - transform.position;
        float angle = Vector3.Angle(targetDir, transform.forward);

        if (angle < 5.0f)
            print("close");
    }
}

See Also: SignedAngle function.