public Vector3 GetVertexNormal(int index)
        {
            Vector3 normal = Vector3.Zero;
            for (int i = 0; i < Indices.Length; i++)
            {
                if (Indices[i] == index)
                {
                    normal += DataHelper.GetNormalFromCCWTriangle(Vertices[Indices[i - (i % 3)]], Vertices[Indices[i - (i % 3) + 1]], Vertices[Indices[i - (i % 3) + 2]]);
                    i += 3 - (i % 3);
                }
            }
            normal.Normalize();
            return normal;
        }