Creating and Viewing Geometries

{
   //
   // This macro generates two canvases.
   // The  first Canvas 
   // has 2 views of the ATLAS detector.
   // The  second Canvas 
   // has 2 views of the NA49 detector.
   //
   gROOT.Reset();
   TCanvas *c1 = gROOT->FindObject("c1"); if (c1) c1->Delete();
   c1 = new TCanvas("c1","The ATLAS canvas",200,10,700,780);

   gBenchmark->Start("atlasna49");
   //
   // Inside the ATLAS canvas, we create 2 pads for 2 different ATLAS views
   //
   TPad oute("oute","Outer Detector",0.02,0.02,0.48,0.82,18);
   TPad gaas("cryo","Ga Arsenite Detector",0.52,0.02,0.98,0.82,18);
   oute.Draw();
   gaas.Draw();
   TPaveLabel atlastitle(0.1,0.86,0.9,0.98,"Two views of the ATLAS detector");
   atlastitle.SetFillColor(28);
   atlastitle.Draw();
   //
   // Connect ROOT file with the ATLAS detector geometry.
   // See TGeometry for explanations how this file was produced.
   //
   TFile atgeom("atlas.root");
   //
   //
   // ATLAS is a barrel detector. Let's make an exploded view.
   atlas.cd();    //Set current geometry
   atlas.SetBomb(2);
   //
   // Set colors
   FMUC2.SetLineColor(5);
   RPCB1.SetLineColor(3);
   RPTI1.SetLineColor(4);
   RPT12.SetLineColor(4);
   RPT23.SetLineColor(3);
   RPT34.SetLineColor(3);
   oute.cd();    //Set current pad
   OUTE1.Draw();
   c1->Update();
   GAAS1.SetVisibility(0);
   GDSI2.SetVisibility();
   GDSI2.SetLineColor(5);
   GSUP1.SetLineColor(2);
   gaas.cd();
   GAAS1.Draw();
   c1->Update();
   //
   // Repeat similar operation for the NA49 detector.
   //
   TCanvas *c2 = gROOT->FindObject("c2"); if (c2) c2->Delete();
   c2 = new TCanvas("c2","The NA49 canvas",280,50,700,780);

   TPad all("all","A Global view of NA49",0.02,0.02,0.48,0.82,18);
   TPad tof("tof","One Time Of Flight element",0.52,0.02,0.98,0.82,18);
   all.Draw();
   tof.Draw();
   TPaveLabel na49title(0.1,0.86,0.9,0.98,"Two views of the NA49 detector");
   na49title.SetFillColor(28);
   na49title.Draw();
   //
   TFile nageom("na49.root");
   na49.SetBomb(1.2);
   na49.cd();    //Set current geometry
   all.cd();     //Set current pad
   na49.Draw();
   c2.Update();
   tof.cd();
   TOFR1.Draw();
   c2.Update();

   gBenchmark->Show("atlasna49");

   // To have a better and dynamic view of any of these pads,
   // you can click with the middle button of your mouse to select it.
   // Then select "View with x3d" in the VIEW menu of the Canvas.
   // Once in x3d, you are in wireframe mode by default.
   // You can switch to:
   //   - Hidden Line mode by typing E
   //   - Solid mode by typing R
   //   - Wireframe mode by typing W
   //   - Stereo mode by clicking S (and you need special glasses)
   //   - To leave x3d type Q
}