Creating a Stacked 2D Histogram and Displaying Transparency in 3D

ROOT
1

Hi All,

I’ve made quite a few attempts to make the following occur with ROOT. I have two 2D (TH2*) histograms that are stacked via a THStack. I can then plot this stack similar to what is seen in the lower right corner of this image:

2088×2016
.

Is there anyway to make one of the 2D histograms in the stack more transparent so that I can see the contents underneath? In this case, that would be making the red boxes have some lesser opacity.

Thanks!
John

2

This one almost work… but some work would be needed to make sure the side of the lego is also transparent

void hstacktrans()
{

   THStack *a = new THStack("a","Stacked 2D histograms");
   TF2 *f1 = new TF2("f1","xygaus + xygaus(5) + xylandau(10)",-4,4,-4,4);
   Double_t params[] = {130,-1.4,1.8,1.5,1, 150,2,0.5,-2,0.5,3600,-2,0.7,-3,0.3};
   f1->SetParameters(params);
   TH2F *h2sta = new TH2F("h2sta","h2sta",20,-4,4,20,-4,4);
   h2sta->SetFillColor(38);
   h2sta->FillRandom("f1",4000);
   TF2 *f2 = new TF2("f2","xygaus + xygaus(5)",-4,4,-4,4);
   Double_t params2[] = {100,-1.4,1.9,1.1,2, 80,2,0.7,-2,0.5};
   f2->SetParameters(params2);
   TH2F *h2stb = new TH2F("h2stb","h2stb",20,-4,4,20,-4,4);
   h2stb->SetFillColorAlpha(46,0.1);
   h2stb->FillRandom("f2",3000);
   a->Add(h2sta);
   a->Add(h2stb);
   a->Draw( "lego3");
}