Poser already has volumetric lighting and fog effects, those 2 things were introduced in version 6 along with IBLs.  Mind you I don't find that those lighting setups are intuitive or easy to use, but they are there. 

If I were going to use volumetric lighting, I find Carrrara's a lot easier to deal with.  I think that Carrarra also does radiosity--I know that Vue does.

I've tried avoiding 64 bit computing because not all my hardware or software is compatible with it.  I think the trade off, being able to use Vue more effectively--is not worth it to me.  This is a case where there are "lesser" grade versions, but they all use system resources the same way--badly.  My main gripe is that they should tell you when you buy the thing that it won't run effectively on systems such as mine.  The new version was touted as being able to optimize Poser figures and textures and use less system resources.  Out and out lies.  In fact many Vue users had down graded back to version 5 because they said they 6 worked even more poorly with their Poser content (even though it was a main selling point that it was supposed to work better).