Adding 2D curve to a 3D plot

Hello all,

is it possible to add 2D curves to a 3D plot.

Please see the two gifs I have attacted…the 2D plot has a red circle on it which I would like to have plotted on the 2D projection in the 3D plot.

Can this be done?


TF2 is what you need.

Here is a small example showing how to superimpose 3D lines on a 3D surface:

   int NBins = 50;
   double d = 2;

   TH2F* h2 = new TH2F("h2", "h2", NBins, -d, d, NBins, -d, d);
   for (int bx = 1;  bx <= NBins; ++bx) {
     for (int by = 1;  by <= NBins; ++by) {
       double x = h2->GetXaxis()->GetBinCenter(bx);
       double y = h2->GetYaxis()->GetBinCenter(by);
       h2->SetBinContent(bx, by, exp(-x*x)*exp(-y*y));

   TCanvas *c1=new TCanvas("c1","c1",600,600);

   int LineBins = 100;
   TPolyLine3D *l = 0;
   for (double h = 0; h < 0.9*d; h+= d/20.0) {
     l = new TPolyLine3D(LineBins);
     for (int e = 0; e < LineBins; ++e) {
       Double_t Angle = e*2*TMath::Pi()/LineBins;
       l->SetPoint(e, h*cos(Angle), h*sin(Angle), exp(-h*h));


wow…just what I was looking for.