public void Invert()
{
for (int i = 0; i < Polygons.Count; i++)
{
Polygons[i].Flip();
}
Plane.Flip();
Front?.Invert();
Back?.Invert();
var temp = Front;
Front = Back;
Back = temp;
}
public void Flip()
{
Vertices.Reverse();
Vertices.ForEach(v => v.Flip());
Plane.Flip();
}