Geant4 Geometry and Visualization

Visualisation, overlap detection are closely related to geometry conversion. So tools that do these should be mined for possibilities.

• google:geant4 visualization geometry conversion
• http://geant4.web.cern.ch/geant4/UserDocumentation/UsersGuides/ForApplicationDeveloper/html/ch08.html
• http://geant4.web.cern.ch/geant4/G4UsersDocuments/UsersGuides/ForApplicationDeveloper/html/Visualization/visdrivers.html
• http://nuclear.unh.edu/~maurik/GEANT4/GEANT4_GEOM.html

Drivers: OpenGL, HepRep, VRML, DAVID, DAWN

• VRML is looking the most promising, as its the most widely supported format exportable

Drivers

[blyth@cms01 visualization]$ du -hs *
1.3M    OpenGL
1.1M    HepRep
1.1M    management
884K    OpenInventor
812K    modeling
508K    XXX
428K    VRML
420K    RayTracer
380K    externals
304K    FukuiRenderer
132K    History
184K    Tree
8.0K    GNUmakefile
[blyth@cms01 visualization]$ pwd
/data/env/local/dyb/trunk/external/build/LCG/geant4.9.2.p01/source/visualization

DAVID

• http://geant4.web.cern.ch/geant4/G4UsersDocuments/UsersGuides/ForApplicationDeveloper/html/Detector/geomOverlap.html

The Geant4 DAVID visualization tool can infact automatically detect the overlaps between the volumes defined in Geant4 and converted to a graphical representation for visualization purposes. The accuracy of the graphical representation can be tuned onto the exact geometrical description. In the debugging, physical-volume surfaces are automatically decomposed into 3D polygons, and intersections of the generated polygons are investigated. If a polygon intersects with another one, physical volumes which these polygons belong to are visualized in color (red is the default).

OpenGL

• http://en.wikipedia.org/wiki/OpenGL

Paint by gl calls approach. Pre-2.0 glsl, so no explicit(useful) geometry conversion.

[blyth@cms01 src]$ vi G4OpenGLSceneHandler.cc
[blyth@cms01 src]$ pwd
/data/env/local/dyb/trunk/external/build/LCG/geant4.9.2.p01/source/visualization/OpenGL/src