Lines in a 3D graph

does anybody know how to draw lines in a 3D Graph? I use the following

   TCanvas *c1 = new TCanvas("c1", "c1", 0, 0, 750, 600);
   TGraph2D *g1 = new TGraph2D();

   for(int i = 0; i < x; i++) g1->SetPoint(i,x[i],y[i],z[i]);


using Draw(“PL”) does not change anything I always get points, but I would like to connect these points by lines??
thanks for help

The option is called “LINE” See: … aph2D:Draw