private void Hexahedron_Click(object sender, EventArgs e)
{
polyhedron = Polyhedron.CreateHexahedron(new My_Point(0, 0, 0), new My_Point(1, 0, 0), new My_Point(0, 1, 0));
Draw();
}
private void buttonHexa_Click(object sender, EventArgs e)
{
ph = Polyhedron.CreateHexahedron(new Point3d(0, 0, 0), new Point3d(1, 0, 0), new Point3d(0, 1, 0));
Plot();
}