Normals

    private void calculateNormals() {
        normals = new Vector[countSides()];
        Vector u;
        Vector v;
        for(int i = 0; i < normals.length; i++) {
            //U = y - x
            u = vertices[i + 1].substract(vertices[i]);
            //V = z - x;
            v = vertices[i + 2].substract(vertices[i]);
            /*
            Nx = Uy*Vz - Uz*Vy
            Ny = Uz*Vx - Ux*Vz
            Nz = Ux*Vy - Uy*Vx
             */
            normals[i] = new Vector(u.y * v.z - u.z * v.y, u.z * v.x - u.x * v.z, u.x * v.y - u.y * v.x);
        }
    }