Just bought City Engine and I've noticed that they have just released a Vue specific version at a very reasonable price (the only export it offers is to Vue, .vob I expect).
City Engine for Vue $199 (http://www.cornucopia3d.com/brokeredfor.php?artist_store=137)
Feature comparison list (http://www.procedural.com/purchase/commercial-solutions/comparison-chart-commercial.html)
Not a bad piece of software for the price.
Here (http://forums.planetside.co.uk/index.php?topic=11359.new#new)is my very first exported render, I put absolutely no effort into this, just wanted to see it working.
:)
Richard