Add locateVolume.C.

README.md

@@ -55,6 +55,54 @@ from the last CI test, but you can also upload root files containing geometries
 yourself. You can use the `gdml2root.C` macro to convert gdml files to root
 files.
 
+# Checking geometry positions
+The macro `locateVolume.C` can be used to check positions of volumes in the
+global coordinate system:
+
+```
+$ root -b -q 'locateVolume.C("nd_hall_with_lar_tms_sand.gdml", "volWorld/rockBox_lv_0/volDetEnclosure_0/volTMS_0/thinlayervol_0/thinvolTMS_0#1")'
+   ------------------------------------------------------------------
+  | Welcome to ROOT 6.30/04                        https://root.cern |
+  | (c) 1995-2024, The ROOT Team; conception: R. Brun, F. Rademakers |
+  | Built for linuxx8664gcc on Feb 03 2024, 23:12:12                 |
+  | From tags/v6-30-04@v6-30-04                                      |
+  | With c++ (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0                   |
+  | Try '.help'/'.?', '.demo', '.license', '.credits', '.quit'/'.q'  |
+   ------------------------------------------------------------------
+
+
+Processing locateVolume.C("nd_hall_with_lar_tms_sand.gdml", "volWorld/rockBox_lv_0/volDetEnclosure_0/volTMS_0/thinlayervol_0/thinvolTMS_0")...
+== Loading Geometry ==
+== Switching to volume path: volWorld/rockBox_lv_0/volDetEnclosure_0/volTMS_0/thinlayervol_0/thinvolTMS_0 ==
+== Volume information ==
+== Volume: thinvolTMS type TGeoVolume positioned 2 times
+*** Shape boxTMS: TGeoBBox ***
+    dX =    87.45000
+    dY =   251.10000
+    dZ =     0.75000
+    origin: x=    0.00000 y=    0.00000 z=    0.00000
+Mixture SteelTMS    Aeff=55.7025 Zeff=25.938 rho=7.85 radlen=1.7654 intlen=16.9869 index=41
+   Element #0 : C  Z=  6.00 A= 12.01 w= 0.000
+   Element #1 : FE  Z= 26.00 A= 55.84 w= 0.995
+   Element #2 : SI  Z= 14.00 A= 28.09 w= 0.004
+== Node information ==
+OBJ: TGeoNodeMatrix	thinvolTMS_0
+== Matrix information ==
+matrix global_5 - tr=1  rot=1  refl=0  scl=0 shr=0 reg=0 own=0
+  1.000000    0.000000    0.000000    Tx = -264.350000
+  0.000000    1.000000    0.000000    Ty = -135.223000
+  0.000000    0.000000    1.000000    Tz = 1139.550000
+```
+
+The Volume information tells us the shape and size of the volume, as well as
+its material. The matrix information tells us the rotation and translation of
+the volume in the global coordinate system.
+
+You can use any of the visualisation methods above to browse the geometry and
+find the paths to the volumes you want to inspect.
+
+Currently this does _not_ work copies of volumes ending with `#<some_number>`.
+
 # Contact
 - **dunendggd:** Package managers
   - Lukas Koch

locateVolume.C

@@ -0,0 +1,20 @@
+void locateVolume(TString filename, TString volname)
+{
+  cout << "== Loading Geometry ==" << endl;
+  TGeoManager *geo = TGeoManager::Import(filename);
+
+  cout << "== Switching to volume path: " << volname << " ==" << endl;
+  geo->cd(volname);
+
+  cout << "== Volume information ==" << endl;
+  TGeoVolume *vol = geo->GetCurrentVolume();
+  vol->Print();
+
+  cout << "== Node information ==" << endl;
+  TGeoNode *node = geo->GetCurrentNode();
+  node->Print();
+
+  cout << "== Matrix information ==" << endl;
+  TGeoMatrix *mat = gGeoManager->GetCurrentMatrix();
+  mat->Print();
+}