public override int GetHashCode()
            {
                var hashCode = 162377905;
                int p1h      = P1 /*.Rounded(4)*/.GetHashCode();
                int p2h      = P2 /*.Rounded(4)*/.GetHashCode();

                if (p1h < p2h)
                {
                    hashCode = hashCode * -1521134295 + p1h;
                    hashCode = hashCode * -1521134295 + p2h;
                }
                else
                {
                    hashCode = hashCode * -1521134295 + p2h;
                    hashCode = hashCode * -1521134295 + p1h;
                }

                hashCode = hashCode * -1521134295 + EdgeNormal.GetHashCode();
                hashCode = hashCode * -1521134295 + FaceNormal.GetHashCode();

                return(hashCode);
            }