GaussTools

# Geant4 Geometry and Visualization¶

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

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¶

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¶

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