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[u/mrichter/AliRoot.git] / FMD / AliFMDv1.cxx
index 1d16ff0cbbde18a175c5b940ff2e5eea34d983e7..129998a0dccc648fbb886b8a14fa2fa51d712e07 100644 (file)
  * about the suitability of this software for any purpose. It is          *
  * provided "as is" without express or implied warranty.                  *
  **************************************************************************/
-
-/*
-$Log$
-Revision 1.11  2000/12/22 11:17:39  hristov
-New FMD code from Alla + code cleaning
-
-Revision 1.10  2000/10/02 21:28:07  fca
-Removal of useless dependecies via forward declarations
-
-Revision 1.9  2000/05/10 21:56:07  fca
-Avoid clashes with ITS and add supports
-
-Revision 1.7  1999/09/29 09:24:14  fca
-Introduction of the Copyright and cvs Log
-
-*/
-
-///////////////////////////////////////////////////////////////////////////////
-//                                                                           //
-//  Forward Multiplicity Detector version 1                                  //
-//                                                                           //
-//Begin_Html
-/*
-<img src="picts/AliFMDv1Class.gif">
-</pre>
-<br clear=left>
-<font size=+2 color=red>
-<p>The responsible person for this module is
-<a href="mailto:Valeri.Kondratiev@cern.ch">Valeri Kondratiev</a>.
-</font>
-<pre>
+/* $Id$ */
+/** @file    AliFMDv1.cxx
+    @author  Christian Holm Christensen <cholm@nbi.dk>
+    @date    Mon Mar 27 12:48:51 2006
+    @brief   Concrete implementation of FMD detector driver - detailed
+    version 
+    @ingroup FMD_sim
 */
-//End_Html
-//                                                                           //
-///////////////////////////////////////////////////////////////////////////////
-
-#include "AliRun.h"
-#include "AliFMDv1.h"
-#include "AliMC.h"
-#include "AliMagF.h"
-#include <stdlib.h>
+//____________________________________________________________________
+//                                                                          
+// Forward Multiplicity Detector based on Silicon wafers. This class
+// contains the base procedures for the Forward Multiplicity detector
+// Detector consists of 3 sub-detectors FMD1, FMD2, and FMD3, each of
+// which has 1 or 2 rings of silicon sensors. 
+// This class contains the detailed version of the FMD - that is, hits
+// are produced during simulation. 
+//                                                                           
+// See also the class AliFMD for a more detailed explanation of the
+// various componets. 
+//
+#include <TVirtualMC.h>                // ROOT_TVirtualMC
+#include <AliRun.h>            // ALIRUN_H
+#include <AliMC.h>             // ALIMC_H
+// #include <AliLog.h>         // ALILOG_H
+#include "AliFMDDebug.h" // Better debug macros
+#include "AliFMDv1.h"          // ALIFMDV1_H
+// #include "AliFMDGeometryBuilder.h"
+#include "AliFMDGeometry.h"
+#include "AliFMDDetector.h"
+#include "AliFMDRing.h"
+#include <TParticlePDG.h>
+#include <TDatabasePDG.h>
+#include "AliFMDHit.h"
+
+//____________________________________________________________________
 ClassImp(AliFMDv1)
-//_____________________________________________________________________________
-AliFMDv1::AliFMDv1()
-{
-  //
-  // Default constructor for FMD version 1
-  //
-}
-//_____________________________________________________________________________
-AliFMDv1::AliFMDv1(const char *name, const char *title)
-  : AliFMD(name,title)
-{
-  //
-  // Standard constructor for FMD version 1
-  //
-  AliModule *start = gAlice->GetModule("START");
-  if(start) {
-    Error("ctor","This version of FMD is incompatible with START\n");
-    exit(1);
-  }
-}
-//___________________________________________
-void AliFMDv1::CreateGeometry()
-{
-  //
-  // Creation of the geometry of the FMD version 1
-  //
-  //Begin_Html
-  /*
-    <img src="picts/AliFMDv1Tree.gif">
-  */
-  //End_Html
-  //Begin_Html
-  /*
-    <img src="picts/AliFMDv1.gif">
-  */
-  //End_Html
-
-  
-  Float_t rout, z;
-  Float_t par[3], rin;
-
-  Int_t irotm[100];
-  
-  TArrayI &idtmed = *fIdtmed;    
-  
-  // ******************************************************** 
-  //       DEFINE DISK#3  OF FMD 
-  // ******************************************************** 
-  
-  gMC->Gsvolu("BR3_", "BOX ", idtmed[4], par, 0);
-  gMC->Gsvolu("CB3_", "BOX ", idtmed[5], par, 0);
-  gMC->Gsvolu("BR5_", "BOX ", idtmed[4], par, 0);
-  gMC->Gsvolu("CB5_", "BOX ", idtmed[5], par, 0);
-
-  //       Define parameters for the right disk 
-  
-  rin  = 4.5;
-  rout = 10.5;
-  z    = 77.;
-
-  //       Ring #1 
-
-  par[0] = rin;
-  par[1] = rout;
-  par[2] = 1.5;
-  gMC->Gsvolu("R1R3", "TUBE", idtmed[1], par, 3);
-  gMC->Gspos("R1R3", 1, "ALIC", 0., 0., z + 1.5, 0, "ONLY");
-
-  //       Ring #2 
-
-  par[0] = rout;
-  par[1] = rout + .65;
-  par[2] = 1.5;
-  gMC->Gsvolu("R2R3", "TUBE", idtmed[2], par, 3);
-  gMC->Gspos("R2R3", 1, "ALIC", 0., 0., z + 1.5, 0, "ONLY");
-
-  //       Ring #3 
-
-  par[0] = rout + .65;
-  par[1] = rout + 5.65;
-  par[2] = .025;
-  gMC->Gsvolu("R3R3", "TUBE", idtmed[3], par, 3);
-  gMC->Gspos("R3R3", 1, "ALIC", 0., 0., z + 1.525, 0, "ONLY");
-
-  //       Bracket #1
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 15.35;
-  gMC->Matrix(irotm[11], 90., 0., 161.2, 90., 71.2, 90.);
-  gMC->Gsposp("BR3_",1,"ALIC", 0., 25.25, 85.0, irotm[11],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB3_",1,"ALIC", 0., 25.41, 84.53,irotm[11],"ONLY",par,3); 
-
-
-  //       Bracket #2
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 15.35;
-  gMC->Matrix(irotm[12], 90., 180., 161.2, 270., 71.2, 270.);
-  gMC->Gsposp("BR3_",2,"ALIC", 0.,-25.25, 85.0, irotm[12],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB3_",2,"ALIC", 0.,-25.41, 84.53,irotm[12],"ONLY",par,3); 
-
-
-  //       Bracket #3
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 15.35;
-  gMC->Matrix(irotm[13], 90., 270., 161.2, 0., 71.2, 0.);
-  gMC->Gsposp("BR3_",3,"ALIC", 25.25, 0., 85.0, irotm[13],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB3_",3,"ALIC", 25.41, 0., 84.53,irotm[13],"ONLY",par,3); 
-
-
-  //       Bracket #4
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 15.35;
-  gMC->Matrix(irotm[14], 90., 90., 161.2, 180., 71.2, 180.);
-  gMC->Gsposp("BR3_",4,"ALIC", -25.25, 0., 85.0, irotm[14],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB3_",4,"ALIC", -25.41, 0., 84.53,irotm[14],"ONLY",par,3); 
-
-  //       Right support ring 
-
-  par[0] = 39.;
-  par[1] = 41.;
-  par[2] = .5;
-  gMC->Gsvolu("R1SP", "TUBE", idtmed[4], par, 3);
-  gMC->Gspos("R1SP", 1, "ALIC", 0., 0., 89.5, 0, "ONLY");
-
-  //       Define parameters for the left disk
-  
-  rin  = 4.5;
-  rout = 10.5;
-  z    = -77.;
-
-  //       Ring #1 
-
-  par[0] = rin;
-  par[1] = rout;
-  par[2] = 1.5;
-  gMC->Gsvolu("R1L3", "TUBE", idtmed[1], par, 3);
-  gMC->Gspos("R1L3", 1, "ALIC", 0., 0., z - 1.5, 0, "ONLY");
-
-  //       Ring #2 
-
-  par[0] = rout;
-  par[1] = rout + .65;
-  par[2] = 1.5;
-  gMC->Gsvolu("R2L3", "TUBE", idtmed[2], par, 3);
-  gMC->Gspos("R2L3", 1, "ALIC", 0., 0., z - 1.5, 0, "ONLY");
-
-  //       Ring #3 
-
-  par[0] = rout + .65;
-  par[1] = rout + 5.65;
-  par[2] = .025;
-  gMC->Gsvolu("R3L3", "TUBE", idtmed[3], par, 3);
-  gMC->Gspos("R3L3", 1, "ALIC", 0., 0., z - 1.525, 0, "ONLY");
-
-  //       Bracket #1
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 15.35;
-  gMC->Matrix(irotm[61], 90., 0., 180.-161.2, 90., 180.-71.2, 90.);
-  gMC->Gsposp("BR3_",5,"ALIC", 0., 25.25, -85.0, irotm[61],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB3_",5,"ALIC", 0., 25.41, -84.53,irotm[61],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[91], 90., 0., 90.-10.6, 90., 180.-10.6, 90.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",1,"ALIC", 0., 55.0, -170.0,irotm[91],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",1,"ALIC", 0., 55.5, -169.5,irotm[91],"ONLY",par,3); 
-
-  //       Bracket #2
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 15.35;
-  gMC->Matrix(irotm[62], 90., 180., 180.-161.2, 270., 180.-71.2, 270.);
-  gMC->Gsposp("BR3_",6,"ALIC", 0.,-25.25, -85.0,irotm[62],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB3_",6,"ALIC", 0.,-25.41, -84.53,irotm[62],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[92], 90., 180., 90.-10.6, 270., 180.-10.6, 270.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",2,"ALIC", 0., -55.0, -170.0,irotm[92],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",2,"ALIC", 0., -55.5, -169.5,irotm[92],"ONLY",par,3); 
-
-  //       Bracket #3
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 15.35;
-  gMC->Matrix(irotm[63], 90., 270., 180.-161.2, 0., 180.-71.2, 0.);
-  gMC->Gsposp("BR3_",7,"ALIC", 25.25, 0., -85.0, irotm[63],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB3_",7,"ALIC", 25.41, 0., -84.53,irotm[63],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[93], 90., 270., 90.-10.6, 0., 180.-10.6, 0.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",3,"ALIC", 55., 0., -170.,irotm[93],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",3,"ALIC", 55.5, 0., -169.5,irotm[93],"ONLY",par,3); 
-
-  //       Bracket #4
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 15.35;
-  gMC->Matrix(irotm[64], 90., 90., 180.-161.2, 180., 180.-71.2, 180.);
-  gMC->Gsposp("BR3_",8,"ALIC", -25.25, 0., -85., irotm[64],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB3_",8,"ALIC", -25.41, 0., -84.53,irotm[64],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[94], 90., 90., 90.-10.6, 180., 180.-10.6, 180.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",4,"ALIC", -55., 0., -170.,irotm[94],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",4,"ALIC", -55.5, 0., -169.5,irotm[94],"ONLY",par,3); 
-
-  //       Central support ring 
-
-  par[0] = 39.;
-  par[1] = 41.;
-  par[2] = .5;
-  gMC->Gsvolu("R2SP", "TUBE", idtmed[4], par, 3);
-  gMC->Gspos("R2SP", 1, "ALIC", 0., 0., -89.5, 0, "ONLY");
-
-  //        Left support ring 
-
-  par[0] = 69.;
-  par[1] = 71.;
-  par[2] = .5;
-  gMC->Gsvolu("R3SP", "TUBE", idtmed[4], par, 3);
-  gMC->Gspos("R3SP", 1, "ALIC", 0., 0., -249.5, 0, "ONLY");
-
-  // ******************************************************** 
-  //       DEFINE  DISK#2  OF FMD 
-  // ******************************************************** 
-  
-  gMC->Gsvolu("BR2_", "BOX ", idtmed[4], par, 0);
-  gMC->Gsvolu("CB2_", "BOX ", idtmed[5], par, 0);
-
-  //       Define parameters for right disk #2
-  
-  rin  = 7.7;
-  rout = 13.7;
-  z    = 64.4;
-
-  //       Ring #1 
-
-  par[0] = rin;
-  par[1] = rout;
-  par[2] = 1.5;
-  gMC->Gsvolu("R1R2", "TUBE", idtmed[1], par, 3);
-  gMC->Gspos("R1R2", 1, "ALIC", 0., 0., z + 1.5, 0, "ONLY");
-
-  //       Ring #2 
-
-  par[0] = rout;
-  par[1] = rout + .65;
-  par[2] = 1.5;
-  gMC->Gsvolu("R2R2", "TUBE", idtmed[2], par, 3);
-  gMC->Gspos("R2R2", 1, "ALIC", 0., 0., z + 1.5, 0, "ONLY");
-
-  //       Ring #3 
-
-  par[0] = rout + .65;
-  par[1] = rout + 5.65;
-  par[2] = .025;
-  gMC->Gsvolu("R3R2", "TUBE", idtmed[3], par, 3);
-  gMC->Gspos("R3R2", 1, "ALIC", 0., 0., z + 1.525, 0, "ONLY");
-
-  //       Bracket #1
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.35;
-  gMC->Matrix(irotm[21], 90., 30., 139.3, 120., 49.3, 120.);
-  gMC->Gsposp("BR2_",1,"ALIC", -13.4, 23.3, 78.7, irotm[21],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB2_",1,"ALIC", -13.56, 23.6, 78.4, irotm[21],"ONLY",par,3); 
-
-  //       Bracket #2
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.35;
-  gMC->Matrix(irotm[22], 90., 210., 139.3, 300., 49.3, 300.);
-  gMC->Gsposp("BR2_",2,"ALIC", 13.4,-23.3, 78.7, irotm[22],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB2_",2,"ALIC", 13.5,-23.6, 78.4,irotm[22],"ONLY",par,3); 
-
-
-  //       Bracket #3
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.35;
-  gMC->Matrix(irotm[23], 90., 300., 139.3, 30., 49.3, 30.);
-  gMC->Gsposp("BR2_",3,"ALIC", 23.3, 13.4, 78.7, irotm[23],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB2_",3,"ALIC", 23.6, 13.56, 78.4,irotm[23],"ONLY",par,3); 
-
-  //       Bracket #4
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.35;
-  gMC->Matrix(irotm[24], 90., 120., 139.3, 210., 49.3, 210.);
-  gMC->Gsposp("BR2_",4,"ALIC", -23.3, -13.4, 78.7,irotm[24],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB2_",4,"ALIC", -23.6, -13.56, 78.4,irotm[24],"ONLY",par,3); 
-
-  //       Define parameters for left disk
-  
-  rin  = 7.7;
-  rout = 13.7;
-  z    = -64.4;
-
-  //       Ring #1 
-
-  par[0] = rin;
-  par[1] = rout;
-  par[2] = 1.5;
-  gMC->Gsvolu("R1L2", "TUBE", idtmed[1], par, 3);
-  gMC->Gspos("R1L2", 1, "ALIC", 0., 0., z - 1.5, 0, "ONLY");
-
-  //       Ring #2 
-
-  par[0] = rout;
-  par[1] = rout + .65;
-  par[2] = 1.5;
-  gMC->Gsvolu("R2L2", "TUBE", idtmed[2], par, 3);
-  gMC->Gspos("R2L2", 1, "ALIC", 0., 0., z - 1.5, 0, "ONLY");
-
-  //       Ring #3 
-
-  par[0] = rout + .65;
-  par[1] = rout + 5.65;
-  par[2] = .025;
-  gMC->Gsvolu("R3L2", "TUBE", idtmed[3], par, 3);
-  gMC->Gspos("R3L2", 1, "ALIC", 0., 0., z - 1.525, 0, "ONLY");
+#if 0
+  ; // This is here to keep Emacs for indenting the next line
+#endif
 
-  //       Bracket #1
 
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.35;
-  gMC->Matrix(irotm[51], 90., 30., 180.-139.3, 120., 180.-49.3, 120.);
-  gMC->Gsposp("BR2_",5,"ALIC", -13.4, 23.3, -78.7, irotm[51],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB2_",5,"ALIC", -13.56, 23.6, -78.4,irotm[51],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[81], 90., 30., 90.-10.6, 120., 180.-10.6, 120.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",5,"ALIC", -27.5, 47.6, -170.0,irotm[81],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",5,"ALIC", -27.85, 48., -169.5,irotm[81],"ONLY",par,3); 
-
-  //       Bracket #2
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.35;
-  gMC->Matrix(irotm[52], 90., 210., 180.-139.3, 300., 180.-49.3, 300.);
-  gMC->Gsposp("BR2_",6,"ALIC", 13.4, -23.3, -78.7,irotm[52],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB2_",6,"ALIC", 13.56, -23.6, -78.4,irotm[52],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[82], 90., 210., 90.-10.6, 300., 180.-10.6, 300.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",6,"ALIC", 27.5, -47.6, -170.0,irotm[82],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",6,"ALIC", 27.85, -48., -169.5,irotm[82],"ONLY",par,3); 
-
-  //       Bracket #3
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.35;
-  gMC->Matrix(irotm[53], 90., 300., 180.-139.3, 30., 180.-49.3, 30.);
-  gMC->Gsposp("BR2_",7,"ALIC", 23.3, 13.4, -78.7, irotm[53],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB2_",7,"ALIC", 23.6, 13.56, -78.4,irotm[53],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[83], 90., 300., 90.-10.6, 30., 180.-10.6, 30.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",7,"ALIC", 47.6, 27.5, -170.,irotm[83],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",7,"ALIC", 48., 27.85, -169.5,irotm[83],"ONLY",par,3); 
-
-  //       Bracket #4
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.35;
-  gMC->Matrix(irotm[54], 90., 120., 180.-139.3, 210., 180.-49.3, 210.);
-  gMC->Gsposp("BR2_",8,"ALIC", -23.3, -13.4, -78.7, irotm[54],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB2_",8,"ALIC", -23.6, -13.56, -78.4,irotm[54],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[84], 90., 120., 90.-10.6, 210., 180.-10.6, 210.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",8,"ALIC", -47.6, -27.5, -170.,irotm[84],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",8,"ALIC", -48., -27.85, -169.5,irotm[84],"ONLY",par,3); 
-
-  // ******************************************************** 
-  //       DEFINE  DISK#1  OF FMD 
-  // ******************************************************** 
-  
-  gMC->Gsvolu("BR1_", "BOX ", idtmed[4], par, 0);
-  gMC->Gsvolu("CB1_", "BOX ", idtmed[5], par, 0);
-  
-  //       Define parameters for right disk #1
+//____________________________________________________________________
+Bool_t
+AliFMDv1::VMC2FMD(TLorentzVector& v, UShort_t& detector,
+                 Char_t& ring, UShort_t& sector, UShort_t& strip) const
+{
+  // Convert VMC coordinates to detector coordinates 
+  TVirtualMC* mc = TVirtualMC::GetMC();
+  AliFMDGeometry*  fmd = AliFMDGeometry::Instance();
+
+  // Get track position
+  mc->TrackPosition(v);
+  Int_t moduleno; mc->CurrentVolOffID(fmd->GetModuleOff(), moduleno);
+  Int_t iring;    mc->CurrentVolOffID(fmd->GetRingOff(), iring);   
+  ring = Char_t(iring);
+  Int_t det;      mc->CurrentVolOffID(fmd->GetDetectorOff(), det); 
+  detector = det;
   
-  rin  = 12.4;
-  rout = 18.4;
-  z    = 59.4;
-
-  //       Ring #1 
-
-  par[0] = rin;
-  par[1] = rout;
-  par[2] = 1.5;
-  gMC->Gsvolu("R1R1", "TUBE", idtmed[1], par, 3);
-  gMC->Gspos("R1R1", 1, "ALIC", 0., 0., z + 1.5, 0, "ONLY");
-
-  //       Ring #2 
-
-  par[0] = rout;
-  par[1] = rout + .65;
-  par[2] = 1.5;
-  gMC->Gsvolu("R2R1", "TUBE", idtmed[2], par, 3);
-  gMC->Gspos("R2R1", 1, "ALIC", 0., 0., z + 1.5, 0, "ONLY");
-
-  //       Ring #3 
 
-  par[0] = rout + .65;
-  par[1] = rout + 5.65;
-  par[2] = .025;
-  gMC->Gsvolu("R3R1", "TUBE", idtmed[3], par, 3);
-  gMC->Gspos("R3R1", 1, "ALIC", 0., 0., z + 1.525, 0, "ONLY");
-
-  //       Bracket #1
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.5;
-  gMC->Matrix(irotm[31], 90., 60., 128., 150., 38., 150.);
-  gMC->Gsposp("BR1_",1,"ALIC", -25.3, 14.6, 76.2, irotm[31],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB1_",1,"ALIC", -25.35, 14.8, 75.9, irotm[31],"ONLY",par,3); 
-
-  //       Bracket #2
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.5;
-  gMC->Matrix(irotm[32], 90., 240., 128., 330., 38., 330.);
-  gMC->Gsposp("BR1_",2,"ALIC", 25.3, -14.6, 76.2, irotm[32],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB1_",2,"ALIC", 25.35, -14.8, 75.9,irotm[32],"ONLY",par,3); 
-
-  //       Bracket #3
+  // Get the ring geometry
+  //Int_t     nsec = fmd->GetDetector(detector)->GetRing(ring)->GetNSectors();
+  Int_t     nstr  = fmd->GetDetector(detector)->GetRing(ring)->GetNStrips();
+  Double_t  lowr  = fmd->GetDetector(detector)->GetRing(ring)->GetMinR();
+  Double_t  theta = fmd->GetDetector(detector)->GetRing(ring)->GetTheta();
+  Double_t  pitch = fmd->GetDetector(detector)->GetRing(ring)->GetPitch();
+
+  // Figure out the strip number
+  Double_t r     = TMath::Sqrt(v.X() * v.X() + v.Y() * v.Y());
+  Int_t    str   = Int_t((r - lowr) / pitch);
+  if (str < 0 || str >= nstr) return kFALSE;
+  strip          = str;
+
+  // Figure out the sector number
+  Double_t phi    = TMath::ATan2(v.Y(), v.X()) * 180. / TMath::Pi();
+  if (phi < 0) phi = 360. + phi;
+  Double_t t      = phi - 2 * moduleno * theta;
+  sector          = 2 * moduleno;
+  if (t < 0 || t > 2 * theta) return kFALSE;
+  else if (t > theta)         sector += 1;
+
+  AliFMDDebug(40, ("<1> Inside an active FMD volume FMD%d%c[%2d,%3d] %s",
+                   detector, ring, sector, strip, mc->CurrentVolPath()));
+  return kTRUE;
+}
 
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.5;
-  gMC->Matrix(irotm[33], 90., 330., 128., 60., 38., 60.);
-  gMC->Gsposp("BR1_",3,"ALIC", 14.6, 25.3, 76.2, irotm[33],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB1_",3,"ALIC", 14.8, 25.35, 75.9,irotm[33],"ONLY",par,3); 
+//____________________________________________________________________
+Bool_t
+AliFMDv1::VMC2FMD(Int_t copy, TLorentzVector& v,
+                 UShort_t& detector, Char_t& ring,
+                 UShort_t& sector, UShort_t& strip) const
+{
+  // Convert VMC coordinates to detector coordinates 
+  TVirtualMC* mc = TVirtualMC::GetMC();
+  AliFMDGeometry* fmd = AliFMDGeometry::Instance();
+
+  strip = copy - 1;
+  Int_t sectordiv; mc->CurrentVolOffID(fmd->GetSectorOff(), sectordiv);
+  if (fmd->GetModuleOff() >= 0) {
+    Int_t module;    mc->CurrentVolOffID(fmd->GetModuleOff(), module);
+    sector = 2 * module + sectordiv;
+  }
+  else 
+    sector = sectordiv;
+  AliFMDDebug(30, ("Getting ring volume with offset %d -> %s", 
+                   fmd->GetRingOff(), 
+                   mc->CurrentVolOffName(fmd->GetRingOff())));
+  Int_t iring;     mc->CurrentVolOffID(fmd->GetRingOff(), iring); 
+  ring = Char_t(iring);
+  Int_t det;       mc->CurrentVolOffID(fmd->GetDetectorOff(), det); 
+  detector = det;
+
+  //Double_t  rz  = fmd->GetDetector(detector)->GetRingZ(ring);
+  AliFMDDetector* gdet  = fmd->GetDetector(detector);
+  AliFMDRing*     gring = gdet->GetRing(ring);
+  if (!gring) {
+    AliFatal(Form("Ring %c not found (volume was %s at offset %d in path %s)", 
+                 ring, fmd->GetRingOff(), 
+                 mc->CurrentVolOffName(fmd->GetRingOff()),
+                 mc->CurrentVolPath()));
+  }
+  Int_t n = gring->GetNSectors();
+#if 0
+  if (rz < 0) {
+    Int_t s = ((n - sector + n / 2) % n) + 1;
+    AliFMDDebug(1, ("Recalculating sector to %d (=%d-%d+%d/2%%%d+1 z=%f)",
+                    s, n, sector, n, n, rz));
+    sector = s;
+  }
+#endif
+  if (sector < 1 || sector > n) {
+    AliWarning(Form("sector # %d out of range (0-%d)", sector-1, n-1));
+    return kFALSE;
+  }
+  sector--;
+  // Get track position
+  mc->TrackPosition(v);
+  AliFMDDebug(15, ("<2> Inside an active FMD volume FMD%d%c[%2d,%3d] %s",
+                   detector, ring, sector, strip, mc->CurrentVolPath()));
 
-  //       Bracket #4
+  return kTRUE;
+}
 
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.5;
-  gMC->Matrix(irotm[34], 90., 150., 128., 240., 38., 240.);
-  gMC->Gsposp("BR1_",4,"ALIC", -14.6, -25.3, 76.2,irotm[34],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB1_",4,"ALIC", -14.8, -25.35, 75.9,irotm[34],"ONLY",par,3); 
 
-  //       Define parameters for left disk #1
+//____________________________________________________________________
+Bool_t
+AliFMDv1::CheckHit(Int_t trackno, Int_t pdg, Float_t absQ, 
+                  const TLorentzVector& p, Float_t edep) const
+{
+  // Check that a hit is good 
+  if (AliLog::GetDebugLevel("FMD", "AliFMD") < 5) return kFALSE;
+  TVirtualMC* mc   = TVirtualMC::GetMC();
+  Double_t mass    = mc->TrackMass();
+  Double_t poverm  = (mass == 0 ? 0 : p.P() / mass);
+    
+  // This `if' is to debug abnormal energy depositions.  We trigger on
+  // p/m approx larger than or equal to a MIP, and a large edep - more 
+  // than 1 keV - a MIP is 100 eV. 
+  if (!(edep > absQ * absQ && poverm > 1)) return kFALSE;
   
-  rin  = 12.4;
-  rout = 18.4;
-  z    = -59.4;
-
-  //       Ring #1 
-
-  par[0] = rin;
-  par[1] = rout;
-  par[2] = 1.5;
-  gMC->Gsvolu("R1L1", "TUBE", idtmed[1], par, 3);
-  gMC->Gspos("R1L1", 1, "ALIC", 0., 0., z - 1.5, 0, "ONLY");
-
-  //       Ring #2 
-
-  par[0] = rout;
-  par[1] = rout + .65;
-  par[2] = 1.5;
-  gMC->Gsvolu("R2L1", "TUBE", idtmed[2], par, 3);
-  gMC->Gspos("R2L1", 1, "ALIC", 0., 0., z - 1.5, 0, "ONLY");
-
-  //       Ring #3 
-
-  par[0] = rout + .65;
-  par[1] = rout + 5.65;
-  par[2] = .025;
-  gMC->Gsvolu("R3L1", "TUBE", idtmed[3], par, 3);
-  gMC->Gspos("R3L1", 1, "ALIC", 0., 0., z - 1.525, 0, "ONLY");
-
-  //       Bracket #1
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.5;
-  gMC->Matrix(irotm[41], 90., 60., 180.-128., 150., 180.-38.0, 150.);
-  gMC->Gsposp("BR1_",5,"ALIC", -25.3, 14.6, -76.2, irotm[41],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB1_",5,"ALIC", -25.35, 14.8, -75.9,irotm[41],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[1], 90., 60., 90.-10.6, 150., 180.-10.6, 150.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",9,"ALIC", -47.6, 27.5, -170.,irotm[1],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",9,"ALIC", -48., 27.85, -169.5,irotm[1],"ONLY",par,3); 
-
-  //       Bracket #2
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.5;
-  gMC->Matrix(irotm[42], 90., 240., 180.-128., 330., 180.-38., 330.);
-  gMC->Gsposp("BR1_",6,"ALIC", 25.3,-14.6, -76.2,irotm[42],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB1_",6,"ALIC", 25.35,-14.8, -75.9,irotm[42],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[2], 90., 240., 90.-10.6, 330., 180.-10.6, 330.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",10,"ALIC", 47.6, -27.5, -170.0,irotm[2],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",10,"ALIC", 48., -27.85, -169.5,irotm[2],"ONLY",par,3); 
-
-  //       Bracket #3
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.5;
-  gMC->Matrix(irotm[43], 90., 330., 180.-128., 60., 180.-38., 60.);
-  gMC->Gsposp("BR1_",7,"ALIC", 14.6, 25.3, -76.2, irotm[43],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB1_",7,"ALIC", 14.8, 25.35, -75.9,irotm[43],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[3], 90., 330., 90.-10.6, 60., 180.-10.6, 60.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",11,"ALIC", 27.5, 47.6, -170.,irotm[3],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",11,"ALIC", 27.85, 48., -169.5,irotm[3],"ONLY",par,3); 
-
-  //       Bracket #4
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 17.5;
-  gMC->Matrix(irotm[44], 90., 150., 180.-128., 240., 180.-38., 240.);
-  gMC->Gsposp("BR1_",8,"ALIC", -14.6, -25.3, -76.2, irotm[44],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB1_",8,"ALIC", -14.8, -25.35, -75.9,irotm[44],"ONLY",par,3); 
-
-  gMC->Matrix(irotm[4], 90., 150., 90.-10.6, 240., 180.-10.6, 240.);
-  par[1] = 0.1;
-  par[2] = 81.4;
-  gMC->Gsposp("BR5_",12,"ALIC", -27.5, -47.6, -170.,irotm[4],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB5_",12,"ALIC", -27.85, -48., -169.5,irotm[4],"ONLY",par,3); 
-
-  // *********************************************************** 
-  //       DEFINE LEFT DISK#4 OF FMD 
-  // *********************************************************** 
-
-  gMC->Gsvolu("BR4_", "BOX ", idtmed[4], par, 0);
-  gMC->Gsvolu("CB4_", "BOX ", idtmed[5], par, 0);
-
-  //       Define parameters 
-
-  rin  = 4.5;
-  rout = 10.5;
-  z    = -229.5;
-
-  //       Ring #1 
-
-  par[0] = rin;
-  par[1] = rout;
-  par[2] = 1.5;
-  gMC->Gsvolu("R1L4", "TUBE", idtmed[1], par, 3);
-  gMC->Gspos("R1L4", 1, "ALIC", 0., 0., z - 1.5, 0, "ONLY");
-
-  //       Ring #2 
-
-  par[0] = rout;
-  par[1] = rout + .65;
-  par[2] = 1.5;
-  gMC->Gsvolu("R2L4", "TUBE", idtmed[2], par, 3);
-  gMC->Gspos("R2L4", 1, "ALIC", 0., 0., z - 1.5, 0, "ONLY");
-
-  //       Ring #3 
-
-  par[0] = rout + .65;
-  par[1] = rout + 5.65;
-  par[2] = .025;
-  gMC->Gsvolu("R3L4", "TUBE", idtmed[3], par, 3);
-  gMC->Gspos("R3L4", 1, "ALIC", 0., 0., z - 1.525, 0, "ONLY");
-
-  //       Bracket #1
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 31.25;
-  gMC->Matrix(irotm[71], 90., 0., 90.-71., 90., 180.-71., 90.);
-  gMC->Gsposp("BR4_",1,"ALIC", 0., 40.25, -240., irotm[71],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB4_",1,"ALIC", 0., 40.75, -239.5, irotm[71],"ONLY",par,3); 
-
-  //       Bracket #2
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 31.25;
-  gMC->Matrix(irotm[72], 90., 180., 90.-71., 270., 180.-71., 270.);
-  gMC->Gsposp("BR4_",2,"ALIC", 0., -40.25, -240., irotm[72],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB4_",2,"ALIC", 0., -40.75, -239.5,irotm[72],"ONLY",par,3); 
-
-  //       Bracket #3
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 31.25;
-  gMC->Matrix(irotm[73], 90., 270., 90.-71., 0., 180.-71., 0.);
-  gMC->Gsposp("BR4_",3,"ALIC", 40.25, 0., -240., irotm[73],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB4_",3,"ALIC", 40.75, 0., -239.5,irotm[73],"ONLY",par,3); 
-
-  //       Bracket #4
-
-  par[0] = 1.5;
-  par[1] = 0.1;
-  par[2] = 31.25;
-  gMC->Matrix(irotm[74], 90., 90., 90.-71., 180., 180.-71., 180.);
-  gMC->Gsposp("BR4_",4,"ALIC", -40.25, 0., -240.,irotm[74],"ONLY",par,3); 
-  par[1] = 0.5;
-  gMC->Gsposp("CB4_",4,"ALIC", -40.75, 0., -239.5,irotm[74],"ONLY",par,3); 
+  TArrayI procs;
+  mc->StepProcesses(procs);
+  TString processes;
+  for (Int_t ip = 0; ip < procs.fN; ip++) {
+    if (ip != 0) processes.Append(",");
+    processes.Append(TMCProcessName[procs.fArray[ip]]);
+  }
+  TDatabasePDG* pdgDB        = TDatabasePDG::Instance();
+  TParticlePDG* particleType = pdgDB->GetParticle(pdg);
+  TString pname(particleType ? particleType->GetName() : "???");
+  TString what;
+  if (mc->IsTrackEntering())    what.Append("entering ");
+  if (mc->IsTrackExiting())     what.Append("exiting ");
+  if (mc->IsTrackInside())      what.Append("inside ");
+  if (mc->IsTrackDisappeared()) what.Append("disappeared ");
+  if (mc->IsTrackStop())        what.Append("stopped ");
+  if (mc->IsNewTrack())         what.Append("new ");
+  if (mc->IsTrackAlive())       what.Append("alive ");
+  if (mc->IsTrackOut())         what.Append("out ");
+      
+  Int_t mother = gAlice->GetMCApp()->GetPrimary(trackno);
+  AliFMDDebug(15, ("Track # %5d deposits a lot of energy\n" 
+                   "  Volume:    %s\n" 
+                   "  Momentum:  (%7.4f,%7.4f,%7.4f)\n"
+                   "  PDG:       %d (%s)\n" 
+                   "  Edep:      %-14.7f keV (mother %d)\n"
+                   "  p/m:       %-7.4f/%-7.4f = %-14.7f\n"
+                   "  Processes: %s\n"
+                   "  What:      %s\n",
+                   trackno, mc->CurrentVolPath(), p.X(), p.Y(), p.Z(),
+                   pdg, pname.Data(), edep, mother, p.P(), mass, 
+                   poverm, processes.Data(), what.Data()));
+  return kTRUE;
 }
 
-//_____________________________________________________________________________
-void AliFMDv1::DrawModule()
-{
-  //
-  // Draw a shaded view of the FMD version 1
-  //
-
-  // Set everything unseen
-  gMC->Gsatt("*", "seen", -1);
-  // 
-  // Set ALIC mother transparent
-  gMC->Gsatt("ALIC","SEEN",0);
-  //
-  // Set the volumes visible
-  gMC->Gsatt("R1R3","SEEN",1);
-  gMC->Gsatt("R2R3","SEEN",1);
-  gMC->Gsatt("R3R3","SEEN",1);
-  gMC->Gsatt("R1L3","SEEN",1);
-  gMC->Gsatt("R2L3","SEEN",1);
-  gMC->Gsatt("R3L3","SEEN",1);
-  gMC->Gsatt("R1R2","SEEN",1);
-  gMC->Gsatt("R2R2","SEEN",1);
-  gMC->Gsatt("R3R2","SEEN",1);
-  gMC->Gsatt("R1L2","SEEN",1);
-  gMC->Gsatt("R2L2","SEEN",1);
-  gMC->Gsatt("R3L2","SEEN",1);
-  gMC->Gsatt("R1R1","SEEN",1);
-  gMC->Gsatt("R2R1","SEEN",1);
-  gMC->Gsatt("R3R1","SEEN",1);
-  gMC->Gsatt("R1L1","SEEN",1);
-  gMC->Gsatt("R2L1","SEEN",1);
-  gMC->Gsatt("R3L1","SEEN",1);
-  gMC->Gsatt("R1L4","SEEN",1);
-  gMC->Gsatt("R2L4","SEEN",1);
-  gMC->Gsatt("R3L4","SEEN",1);
-  gMC->Gsatt("BR1_","SEEN",1);
-  gMC->Gsatt("BR2_","SEEN",1);
-  gMC->Gsatt("BR3_","SEEN",1);
-  gMC->Gsatt("BR4_","SEEN",1);
-  gMC->Gsatt("BR5_","SEEN",1);
-  gMC->Gsatt("CB1_","SEEN",1);
-  gMC->Gsatt("CB2_","SEEN",1);
-  gMC->Gsatt("CB3_","SEEN",1);
-  gMC->Gsatt("CB4_","SEEN",1);
-  gMC->Gsatt("CB5_","SEEN",1);
-  gMC->Gsatt("R1SP","SEEN",1);
-  gMC->Gsatt("R2SP","SEEN",1);
-  gMC->Gsatt("R3SP","SEEN",1);
-  //
-  gMC->Gdopt("hide", "on");
-  gMC->Gdopt("shad", "on");
-  gMC->Gsatt("*", "fill", 7);
-  gMC->SetClipBox(".");
-  gMC->SetClipBox("*", 0, 1000, -1000, 1000, -1000, 1000);
-  gMC->DefaultRange();
-  gMC->Gdraw("alic", 40, 30, 0, 6, 9, .08, .08);
-  gMC->Gdhead(1111, "Forward Multiplicity Detector version 1");
-  gMC->Gdman(13, 9, "MAN");
-}
 
-//_____________________________________________________________________________
-void AliFMDv1::CreateMaterials()
+//____________________________________________________________________
+void 
+AliFMDv1::StepManager()
 {
+  // Member function that is executed each time a hit is made in the
+  // FMD.  None-charged particles are ignored.   Dead tracks  are
+  // ignored. 
   //
-  // Create Materials for version 1 of FMD
-  //
-
-  //     Material for ring #1 
-  Float_t ar1[8] = { 55.8,58.7,52.,47.9,16.,28.,207.2,27. };
-  Float_t zr1[8] = { 26.,28.,24.,22.,8.,14.,82.,13. };
-  Float_t wr1[8] = { .27,.081,.054,.045,.18,.25,.06,.06 };
-  //     Material for ring #2 
-  Float_t ar2[3] = { 55.8,27.,16. };
-  Float_t zr2[3] = { 26.,13.,8. };
-  Float_t wr2[3] = { .35,.34,.31 };
-  //     Material for ring #3 
-  Float_t ar3[3] = { 28.,27.,16. };
-  Float_t zr3[3] = { 14.,13.,8. };
-  Float_t wr3[3] = { .37,.33,.3 };
-  //     Material for brackets 
-  Float_t abr[2] = { 1.,12. };
-  Float_t zbr[2] = { 1.,6. };
-  Float_t wbr[2] = { .1,.9 };
-  //     Material for cables 
-  Float_t acb[4] = { 1.,12.,37.,63.54 };
-  Float_t zcb[4] = { 1.,6.,17.,2.9 };
-  Float_t wcb[4] = { .02,.14,.12,.72 };
-  
-  Float_t epsil, stmin, deemax, tmaxfd, stemax;
-  
-  Int_t   isxfld = gAlice->Field()->Integ();
-  Float_t sxmgmx = gAlice->Field()->Max();
-  
-  //     Ring #1 
-  
-  AliMixture(1, "FMD_R1$", ar1, zr1, 2.69, 8, wr1);
-  
-  //     Ring #2 
-  
-  AliMixture(2, "FMD_R2$", ar2, zr2, 2.63, 3, wr2);
-  
-  //     Ring #3 
+  // The procedure is as follows: 
+  // 
+  //   - IF NOT track is alive THEN RETURN ENDIF
+  //   - IF NOT particle is charged THEN RETURN ENDIF
+  //   - IF NOT volume name is "STRI" or "STRO" THEN RETURN ENDIF 
+  //   - Get strip number (volume copy # minus 1)
+  //   - Get phi division number (mother volume copy #)
+  //   - Get module number (grand-mother volume copy #)
+  //   - section # = 2 * module # + phi division # - 1
+  //   - Get ring Id from volume name 
+  //   - Get detector # from grand-grand-grand-mother volume name 
+  //   - Get pointer to sub-detector object. 
+  //   - Get track position 
+  //   - IF track is entering volume AND track is inside real shape THEN
+  //   -   Reset energy deposited 
+  //   -   Get track momentum 
+  //   -   Get particle ID # 
+  ///  - ENDIF
+  //   - IF track is inside volume AND inside real shape THEN 
+  ///  -   Update energy deposited 
+  //   - ENDIF 
+  //   - IF track is inside real shape AND (track is leaving volume,
+  //         or it died, or it is stopped  THEN
+  //   -   Create a hit 
+  //   - ENDIF
+  //     
+  TVirtualMC* mc = TVirtualMC::GetMC();
+  if (!mc->IsTrackAlive()) return;
+  Double_t absQ = TMath::Abs(mc->TrackCharge());
+  if (absQ <= 0) return;
   
-  AliMixture(3, "FMD_R3$", ar3, zr3, 3.15, 3, wr3);
-
-  //     Brackets 
+  Int_t copy;
+  Int_t vol = mc->CurrentVolID(copy);
+  AliFMDGeometry*  fmd = AliFMDGeometry::Instance();
+  if (!fmd->IsActive(vol)) {
+    AliFMDDebug(50, ("Not an FMD volume %d '%s'",vol,mc->CurrentVolName()));
+    return;
+  }
+  TLorentzVector v;
+  UShort_t       detector;
+  Char_t         ring;
+  UShort_t       sector;
+  UShort_t       strip;
   
-  AliMixture(4, "FMD_BR$", abr, zbr, 1.8, 2, wbr);
-
-  //     Cables
+  if (fmd->IsDetailed()) {
+    if (!VMC2FMD(copy, v, detector, ring, sector, strip)) return;
+  } else {
+    if (!VMC2FMD(v, detector, ring, sector, strip)) return;
+  }
+  TLorentzVector p;
+  mc->TrackMomentum(p);
+  Int_t    trackno = gAlice->GetMCApp()->GetCurrentTrackNumber();
+  Int_t    pdg     = mc->TrackPid();
+  Double_t edep    = mc->Edep() * 1000; // keV
+  Bool_t   isBad   = CheckHit(trackno, pdg, absQ, p, edep);
   
-  AliMixture(5, "FMD_CB$", acb, zcb, 3.11, 4, wcb);
-
-  // ******************************************************* 
-  //     Defines tracking media parameters. 
-  // ******************************************************* 
-  epsil  = .001; // Tracking precision, DLS 
-  stemax = -1.;  // Maximum displacement for multiple scattering 
-  tmaxfd = -20.; // Maximum angle due to field deflection 
-  deemax = -.3;  // Maximum fractional energy loss, DLS 
-  stmin  = -.8;
-  // ******************************************************** 
-  AliMedium(1, "FMD_R1_L3        ", 1, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
-  AliMedium(2, "FMD_R2_L3        ", 2, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
-  AliMedium(3, "FMD_R3_L3        ", 3, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
-  AliMedium(4, "FMD_BR_L3        ", 4, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
-  AliMedium(5, "FMD_CB_L3        ", 5, 0, isxfld, sxmgmx, tmaxfd, stemax, deemax, epsil, stmin);
+  // Check that the track is actually within the active area 
+  Bool_t entering = mc->IsTrackEntering();
+  Bool_t inside   = mc->IsTrackInside();
+  Bool_t out      = (mc->IsTrackExiting()|| mc->IsTrackDisappeared()||
+                    mc->IsTrackStop());
+  // Reset the energy deposition for this track, and update some of
+  // our parameters.
+  if (entering) {
+    AliFMDDebug(15, ("Track # %8d entering active FMD volume %s: "
+                     "Edep=%f (%f,%f,%f)", trackno, mc->CurrentVolPath(),
+                     edep, v.X(), v.Y(), v.Z()));
+    fCurrentP      = p;
+    fCurrentV      = v;    
+    fCurrentDeltaE = edep;
+    fCurrentPdg    = pdg; // mc->IdFromPDG(pdg);
+  }
+  // If the track is inside, then update the energy deposition
+  if (inside && fCurrentDeltaE >= 0) {
+    fCurrentDeltaE += edep;
+    AliFMDDebug(15, ("Track # %8d inside active FMD volume %s: Edep=%f, "
+                     "Accumulated Edep=%f  (%f,%f,%f)", trackno, 
+                     mc->CurrentVolPath(), edep, fCurrentDeltaE, 
+                     v.X(), v.Y(), v.Z()));
+  }
+  // The track exits the volume, or it disappeared in the volume, or
+  // the track is stopped because it no longer fulfills the cuts
+  // defined, then we create a hit. 
+  if (out) {
+    if (fCurrentDeltaE >= 0) {
+      fCurrentDeltaE += edep;
+      AliFMDDebug(15, ("Track # %8d exiting active FMD volume %s: Edep=%g, "
+                       "Accumulated Edep=%g (%f,%f,%f)", trackno, 
+                       mc->CurrentVolPath(), edep, fCurrentDeltaE, 
+                       v.X(), v.Y(), v.Z()));
+      TVector3 cur(v.Vect());
+      cur -= fCurrentV.Vect();
+      Double_t len = cur.Mag();
+      AliFMDHit* h = 
+       AddHitByFields(trackno, detector, ring, sector, strip,
+                      fCurrentV.X(),  fCurrentV.Y(), fCurrentV.Z(),
+                      fCurrentP.X(),  fCurrentP.Y(), fCurrentP.Z(), 
+                      fCurrentDeltaE, fCurrentPdg,   fCurrentV.T(), 
+                      len, mc->IsTrackDisappeared()||mc->IsTrackStop());
+      // Add a copy 
+      if (isBad && fBad) { 
+       new ((*fBad)[fBad->GetEntries()]) AliFMDHit(*h);
+      }
+      // Check the geometry that we can get back the coordinates. 
+#ifdef CHECK_TRANS
+      Double_t x, y, z;
+      fmd->Detector2XYZ(detector, ring, sector, strip, x, y ,z);
+      AliFMDDebug(1, ("Hit at (%f,%f,%f), geometry says (%f,%f,%f)", 
+                      fCurrentV.X(), fCurrentV.Y(), fCurrentV.Z(), x, y, z));
+#endif
+    }
+    fCurrentDeltaE = -1;
+  }
 }
-
-
+//___________________________________________________________________
+//
+// EOF
+//