Unity judges the orientation and angle of other objects relative to itself

    // find the angle and the front, back, left and right directions
    public void checkTargetDirForMe(Transform target)
    {
        //xuqiTest：  target.position = new Vector3(3, 0, 5);
        Vector3 dir = target.position - transform.position; //Position difference, direction
        //method 1 dot multiplication
        //The calculation method of the dot product is: a · b =| a | · | b | cos < a,b > where | a | and | b | represent the modulus of the vector.
        float dot = Vector3.Dot(transform.forward, dir.normalized);//The dot product is judged before and after//dot >0 is in the front <0 is in the back
        float dot1 = Vector3.Dot(transform.right, dir.normalized);//Dot multiplication to judge left and right//dot1>0 is on the right<0 is on the left                                               
        float angle = Mathf.Acos(Vector3.Dot(transform.forward.normalized, dir.normalized)) * Mathf.Rad2Deg;//Calculate the angle by dot product

        //method 2 cross product
        //The cross product satisfies the right-hand criterion formula: modulo length |c|=|a||b|sin<a,b>  
        Vector3 cross = Vector3.Cross(transform.forward, dir.normalized);////Dot multiplication to judge left and right// cross.y>0 is on the left<0 is on the right
        Vector3 cross1 = Vector3.Cross(transform.right, dir.normalized);////The dot product is judged before and after// cross.y>0 is in the front<0 is in the back
        angle = Mathf.Asin(Vector3.Distance(Vector3.zero, Vector3.Cross(transform.forward.normalized, dir.normalized))) * Mathf.Rad2Deg;
        
    }

20161202 15:13