Check if the OpenGL libraries are correctly installed on your system. Geant4 search this libraries in /usr directory. What linux version are you use? <div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Message: 1 Date: Sat, 4 Apr 2009 01:42:02 -0500 From: Naser Darwish <<a href="mailto:naser.darwish@gmail.com">naser.darwish@gmail.com</a>> Subject: [Gate-users] Cannot get visualization to work with GATE To: <a href="mailto:gate-users@lists.healthgrid.org">gate-users@lists.healthgrid.org</a> Message-ID: <<a href="mailto:48b9aacc0904032342w158a4dc8n74fd9223014916c3@mail.gmail.com">48b9aacc0904032342w158a4dc8n74fd9223014916c3@mail.gmail.com</a>> Content-Type: text/plain; charset=ISO-8859-1 Dear GATE users, I have geant4.9.1.p02 with GATE 4.0 installed and I can get the simulation to work without visualization. However, I would like to be able to use the visualization openGL but I cannot get it to work. What is the mechanism of the steps for visualization prior to and after simulation? I do not know how to get the visualization to work. I am following the GATE manual in setting up the visualization script and I know that openGL should be installed because when I initialize, I get the following comment: On this machine the G4VIS_USE_OPENGLX=1 This what I type for visualization in the GATE script #VISUALIZATION /vis/open OGLSX /vis/viewer/reset /vis/viewer/set/viewpointThetaPhi 90 90 /vis/viewer/zoom 2 /vis/viewer/set/style surface /vis/drawVolume /tracking/storeTrajectory 1 /vis/scene/endOfEventAction accumulate /vis/viewer/update /vis/verbose 2 /gate/geometry/enableAutoUpdate The error message I get is: ERROR: G4VisManager::IsValidView(): Current view is not valid. ERROR: G4VisManager::PrintInvalidPointers: Graphics system is OpenGLStoredX but: Null viewer pointer. Use "/vis/viewer/create". I appreciate the help. Best regards, Naser </blockquote></div> -- e- + e+ -> <~~*~~>