Calculate the angle between two 3d vectors: Function always returns 89.1-89.9

Unity Engine
1

Hello

I have my own 2d game and I am attempting to calculate the angle between 2 GameObjects.

My Problem: My function that is meant to calculate the angle(direction) between 2 Vector3’s doesn’t appear to be correctly calculating the angle. It always returns a value thats between 89.1 and 89.9, its never any other value.

What am I doing wrong? Can you help me to get my function to correctly calculate the angle between 2 Vector3’s?

float getAngle(Vector3 p1, Vector3 p2) {
	
	// If p1 or p2 == Vector3.zero then this funciton wont work. What shd I do in this case?

	float coefI  = p1.x * p2.x;
	float coefJ  = p1.y * p2.y;
	float coefK  = p1.z * p2.z;
	float scalar = coefI + coefJ + coefK; 
	float magnitude1 = p1.sqrMagnitude;
	float magnitude2 = p2.sqrMagnitude; 
	
	Debug.Log (System.String.Format ("{0}, {1}, {2}, {3}, {4}, {5}", coefI, coefJ, coefK, scalar, magnitude1, magnitude2));
	return (Mathf.Acos ( scalar / (magnitude1 * magnitude2) ) * Mathf.Rad2Deg); // Always returns between 89.1 and 89.9 for some reason
}

void Update() {
	Debug.Log( getAngle (Input.mousePosition, transform.position) );
}
2

To get the Angle between two vectors, you can use Vector3.Angle or do it manually(ish) but make sure you normalize those vectors otherwise you’ll get those bad results.

angle = Vector3.Angle(forward, targetPosition - myPosition);

// or ...
// Make sure vectors are normalized
angle = Mathf.Acos(Vector3.Dot(forward, otherVectorNormalized)) * Mathf.Rad2Deg;