open scene graph in tgea/T3d

I was wondering if I have an open scene graph application. From www.sundog-soft.com/
Is it possible to intergrate it into any of the GG based engines (TGEA or T3D)?
I'm wanting to do a flight simulator with volumetric clouds. If possible, anyone that can help me or guide me to the right place so I can intergrate it into my project I would apprechiate it!

thanks