Just an item of potential interest: there are some informational videos showing the capabilities and methods used by the architectural app “Sketchup” here:
Thot this might be of interest to those who like to learn how other tools get the job done. Pretty neat stuff. I particularly like how the software “hides” the technical details behind the scene so that the user can just sketch out what he/she wants to illustrate. Another way to handle the whole “techie vs. artist” balance in visualization software.