Editing Geant4 Detector Geometry (section)

===Creating the Geometry inside the Envelope===
Inside the <span style="color:blue">'''envelope'''</span> you can conduct many types of experiments. For our experiment we have placed two scoring volumes inside our <span style="color:blue">'''envelope'''</span>. Remember, each volume is created by describing its shape and its physical characteristics, and then placing it inside a containing volume; Please Refer to [http://jlabdaq.pcs.cnu.edu/wiki/index.php/Program_Structure#The_Envelope_.28The_world_within_the_world.29 The Envelope (The world within the world)]
A sample code of someone creating the <span style="color:blue">'''envelope'''</span>:
'''A shape'''
In this section of code we are defining the shape in our chosen coordinate system, which is Cartesian. Follow the comments throughout the code for a better understanding:
 G4Material* shape1_mat = nist->FindOrBuildMaterial("MATERIAL");
  G4ThreeVector pos1 = G4ThreeVector(x, y ,z);
  // whatever shape you want     
  G4double shape1_dya = cm, shape1_dyb = cm;
  G4double shape1_dxa = cm, shape1_dxb = cm;
  G4double shape1_dz  = cm;      
  G4Trd* '''solid'''Shape1 =    
    new G4Trd("Shape1",                      //its name
              0.5*shape1_dxa, 0.5*shape1_dxb, 
              0.5*shape1_dya, 0.5*shape1_dyb, 0.5*shape1_dz); //its size
                
  G4LogicalVolume* '''logic'''Shape1 =                         
    new G4LogicalVolume('''solid'''Shape1,         //its solid
                        shape1_mat,          //its material
                        "Shape1");           //its name
               
  new G4PVPlacement(0,                       //no rotation
                    pos1,                    //at position
                    logicShape1,             //its logical volume
                    "Shape1",                //its name
                    logicEnv,                //its mother  volume
                    false,                   //no boolean operation
                    0,                       //copy number
                    checkOverlaps);          //overlaps checking
                
 
Next is the creation of the scintillators