{
   auto C = new TCanvas("C","C",500,500);
   auto f3 = new TF3("gyroid",
      "sin(x)*cos(y) + sin(y)*cos(z) + sin(z)*cos(x)",
      -4, 4, -4, 4, -4, 4);
   f3->SetFillColor(50);
   f3->SetLineColor(15);
   f3->Draw("FBBB");
}