Operations on Geant4 scene handlers.
| scene-name | type s | Omittable : current value is used as the default value. |
| graphics-system-name | type s | Omittable : default value = error | Parameter candidates : DAWNFILE OGLIX OGLSX VRML1FILE VRML2FILE |
| scene-handler-name | type s | Omittable : current value is used as the default value. |
| scene-handler-name | type s | Omittable : default value = all | |
| verbosity | type s | Omittable : default value = 0 |
| scene-handler-name | type s |
| scene-handler-name | type s | Omittable : current value is used as the default value. |