Sort a set of 3-D points in clockwise/counter-clockwise order

Question

In 3-D space I have an unordered set of, say, 6 points; something like this:

           (A)*
                          (C)*
(E)*
                         (F)         


        

Answer 1

I can't attest for the efficiency of this code, but it works, and you can optimize parts of it as needed, I'm just not good at it.
Code is in C#, using system collection classes, and linq.
Vector3 is a class with floats x, y, z, and static vector math functions.
Node is a class with Vector3 variable called pos

//Sort nodes with positions in 3d space.
//Assuming the points form a convex shape.
//Assuming points are on a single plain (or close to it).

public List sortVerticies( Vector3 normal, List nodes ) {

    Vector3 first = nodes[0].pos;

    //Sort by distance from random point to get 2 adjacent points.
    List temp = nodes.OrderBy(n => Vector3.Distance(n.pos, first ) ).ToList();

    //Create a vector from the 2 adjacent points,
    //this will be used to sort all points, except the first, by the angle to this vector.
    //Since the shape is convex, angle will not exceed 180 degrees, resulting in a proper sort.
    Vector3 refrenceVec = (temp[1].pos - first);

    //Sort by angle to reference, but we are still missing the first one.
    List results = temp.Skip(1).OrderBy(n => Vector3.Angle(refrenceVec,n.pos - first)).ToList();

    //insert the first one, at index 0.
    results.Insert(0,nodes[0]);

    //Now that it is sorted, we check if we got the direction right, if we didn't we reverse the list.
    //We compare the given normal and the cross product of the first 3 point.
    //If the magnitude of the sum of the normal and cross product is less than Sqrt(2) then then there is more than 90 between them.
    if ( (Vector3.Cross( results[1].pos-results[0].pos, results[2].pos - results[0].pos ).normalized + normal.normalized).magnitude < 1.414f ) {
        results.Reverse();
    }

    return results;
}