adding start of progressive rendering updates.
infrastructure to pass volumetric elements to renderers as tetrahedra.
Updated eavlXGCParticle importer to work with staged files.
Merge branch 'master' of https://github.com/jsmeredith/EAVL
Fixed eavlab compilation error in eavlSceneRenderer. Added support for moving the camera in the view direction.
adding a few matrix math helper functions.
adding simple volume renderer
Merge branch 'master' of github.com:jsmeredith/EAVL
adding missing include directive
Merge branch 'master' into rayTracer
save.
Merge branch 'master' into rayTracer
Adding more volume rendering infastructure.