Torus

A torus can be constructed using C++ or some simple text:

:volu torus TORUS
 5 // inner r in mm
 10// outer r in mm
 25// swept radius
 60// phi0 in degree
 99// dphi in degree
 G4_WATER

The full source code is in detector.tg, which can be visualized using the macro file mingle.mac or gears.mac, assuming an universal Geant4 application, such as MinGLE or GEARS, is available:

git clone https://github.com/jintonic/geant4
cd geant4/detector/CSG/torus
# generate animated picture, torus.gif
G4VIS_DEFAULT_DRIVER=TSG_FILE gears gears.mac