[osg-submissions] G4OSG driver and examples ... could this be part of osg?

[Charles Cossé]

Hi Robert & All,

I have developed an OSG  "driver" for the Geant4 library and am
wondering if it would be appropriate to add to OSG?  It allows users
of Geant4 to render their graphics via OSG.  Geant4 is an
industry-standard  particle physics library/toolkit (
http://www.geant4.org/geant4/ ).   It comes with source to compile
"drivers" (in the Geant4 usage of the word, meaning graphics adapters)
for OpenGL, OpenInventor, something called "DAWN" and straight-old
Xlib stuff.  Therefore, this code should naturally be included with
Geant4, and indeed I have discussed it with the graphics guys there,
and they plan to include it when it is more mature.  However, the code
is 99% OSG and osgViewer stuff...complete with 3 examples of using the
pkg with wxOSG, XmOSG and osgViewer to the root window, as well.  So,
for those reasons, it could also fit with OSG to the extent that wxOSG
examples are included with OSG.

A few more notes:

1. A user would have to have Geant4 installed to make use of the
proposed addition (call it G4OSG for now).

2. Part of the work has been to reconcile the build systems.  It now
builds with either CMake of GNUMake (Geant4's natural make system).

3. The code works with the latest released of both OSG and Geant4

4. The G4OSG::SceneHandler class has most basic functionality, but
still needs work handling/converting all arbitrary primitives.

5. I use it every day, and simply the ability to manipulate models
through osgViewer is enough that there's no going back ... ie Geant4
users could be expected to come to love osg someday in the near future
(if they don't already)


And, as a final aside, I have used Geant4 and the G4OSG driver to
shoot G4OpticalPhotons (a class) at complex refracting geometry,
located in an OSG scene, and let the G4 engine take care of all
physics (reflecting, refracting, intersections) to perform some
powerful raytracing.  I know J-S and Adrian from this list are
interested in such things, for example.

Finally, I think having it part of OSG, Geant4, or both, will help me
finish the development details remaining.  Anyway, I could submit
tonight if there's interest.

Thanks,

Charlie Cosse


-- 
AsymptopiaSoftware | Software at theLimit
 www.asymptopia.org