ROOT_528-00b_version: tutorials/geom/assembly.C Source File

00001 //Geometry detector assembly example
00002 //Author: Andrei Gheata
00003    
00004 void assembly()
00005 {
00006 //--- Definition of a simple geometry
00007    gSystem->Load("libGeom");
00008    TGeoManager *geom = new TGeoManager("Assemblies", 
00009       "Geometry using assemblies");
00010    Int_t i;
00011    //--- define some materials
00012    TGeoMaterial *matVacuum = new TGeoMaterial("Vacuum", 0,0,0);
00013    TGeoMaterial *matAl = new TGeoMaterial("Al", 26.98,13,2.7);
00014 //   //--- define some media
00015    TGeoMedium *Vacuum = new TGeoMedium("Vacuum",1, matVacuum);
00016    TGeoMedium *Al = new TGeoMedium("Aluminium",2, matAl);
00017    
00018    //--- make the top container volume
00019    TGeoVolume *top = geom->MakeBox("TOP", Vacuum, 1000., 1000., 100.);
00020    geom->SetTopVolume(top);
00021    
00022    // Make the elementary assembly of the whole structure
00023    TGeoVolume *tplate = new TGeoVolumeAssembly("TOOTHPLATE");
00024 
00025    Int_t ntooth = 5;
00026    Double_t xplate = 25;
00027    Double_t yplate = 50;
00028    Double_t xtooth = 10;
00029    Double_t ytooth = 0.5*yplate/ntooth;
00030    Double_t dshift = 2.*xplate + xtooth;
00031    Double_t xt,yt;
00032    
00033    TGeoVolume *plate = geom->MakeBox("PLATE", Al, xplate,yplate,1);
00034    plate->SetLineColor(kBlue);
00035    TGeoVolume *tooth = geom->MakeBox("TOOTH", Al, xtooth,ytooth,1);
00036    tooth->SetLineColor(kBlue);
00037    tplate->AddNode(plate,1);
00038    for (i=0; i<ntooth; i++) {
00039       xt = xplate+xtooth;
00040       yt = -yplate + (4*i+1)*ytooth;
00041       tplate->AddNode(tooth, i+1, new TGeoTranslation(xt,yt,0));
00042       xt = -xplate-xtooth;
00043       yt = -yplate + (4*i+3)*ytooth;
00044       tplate->AddNode(tooth, ntooth+i+1, new TGeoTranslation(xt,yt,0));
00045    }   
00046 
00047    TGeoRotation *rot1 = new TGeoRotation();
00048    rot1->RotateX(90);
00049    TGeoRotation *rot;
00050    // Make a hexagone cell out of 6 toothplates. These can zip togeather
00051    // without generating overlaps (they are self-contained)
00052    TGeoVolume *cell = new TGeoVolumeAssembly("CELL");
00053    for (i=0; i<6; i++) {
00054       Double_t phi =  60.*i;
00055       Double_t phirad = phi*TMath::DegToRad();
00056       Double_t xp = dshift*TMath::Sin(phirad);
00057       Double_t yp = -dshift*TMath::Cos(phirad);
00058       rot = new TGeoRotation(*rot1);
00059       rot->RotateZ(phi);     
00060       cell->AddNode(tplate,i+1,new TGeoCombiTrans(xp,yp,0,rot));
00061    }   
00062    
00063    // Make a row as an assembly of cells, then combine rows in a honeycomb
00064    // structure. This again works without any need to define rows as 
00065    // "overlapping"
00066    TGeoVolume *row = new TGeoVolumeAssembly("ROW");
00067    Int_t ncells = 5;
00068    for (i=0; i<ncells; i++) {
00069       Double_t ycell = (2*i+1)*(dshift+10);
00070       row->AddNode(cell, ncells+i+1, new TGeoTranslation(0,ycell,0));
00071       row->AddNode(cell,ncells-i,new TGeoTranslation(0,-ycell,0));
00072    }
00073    
00074    Double_t dxrow = 3.*(dshift+10.)*TMath::Tan(30.*TMath::DegToRad());
00075    Double_t dyrow = dshift+10.;
00076    Int_t nrows = 5;
00077    for (i=0; i<nrows; i++) {
00078       Double_t xrow = 0.5*(2*i+1)*dxrow;
00079       Double_t yrow = 0.5*dyrow;
00080       if ((i%2)==0) yrow = -yrow;
00081       top->AddNode(row, nrows+i+1, new TGeoTranslation(xrow,yrow,0));
00082       top->AddNode(row, nrows-i, new TGeoTranslation(-xrow,-yrow,0));
00083    }      
00084       
00085    //--- close the geometry
00086    geom->CloseGeometry();
00087       
00088    geom->SetVisLevel(4);
00089    geom->SetVisOption(0);
00090    top->Draw();
00091 }   
00092