Creating a normal (and rotating around it) using 2 Vector3's and a Quanternion

Questions & Answers
1

So I have just started with Unity and I am not too familiar with it, the same goes for Quanternions.
So as far as I can tell, the way to create a normal to a plane, given 2 vectors, should look something like this:

Quaternion newQuaternion(Transform start, Transform target)
{
	Vector3 f = start.TransformDirection(Vector3.forward);
	Vector3 t = target.position - start.position;
	Vector3 c = Vector3.Cross(f, t);
	Quaternion q = new Quaternion(c.x, c.y, c.z, Vector3.Dot(f, t));
	return q;
}

However, when testing it, by drawing a line with this :

Debug.DrawLine(transform.position, test * -transform.up);

Does not always line up with this line (which it should):

Debug.DrawLine(transform.position, target.position, Color.red);

I realize that Unity has built in LookAt functions and other helpful functions, but I am trying to learn it on my own.

Thank you in advance for the help.

2

Quaternions are scary! haha. No need to modify them directly. Use Quaternion.Euler to convert from a euler angle to quaternion. Or you could set the euler angle of your object using transform.eulerAngles