Hi Bernardo,
thank you for your interest. You should contact the mailing list at
ilasti...@ilastik.org to reach the ilastik / volumina developers.
In this case, I suggest you download ilastik from the web site [1], see
how it works, then look into the volumina code in the binary to figure
out how rendering is done right now.
[1]
http://ilastik.org
There might be other options besides using OpenGL, such as making
better use of Qt. It would be good to look into these briefly when you
write your application.
Cheers,
Burcin