I have never used Vue, or Terragen, or any of the other "world builder" software packages out there, but I think you can get good results using just Poser.  I recently purchased the 3D World Builder kit for Poser, and I am very impressed with it.  It is easy to use and very versatle.  I put together a quick flyby and upload it later so you can see what I'm talking about. 

Based on the images I see in the gallery, this package looks just as good.  More to come.