Hello,
There's a new/free web-based CAD application called Meca Bricks that offers endless possibilities of creating with Lego blocks. You can share your creations as well as 3D print them and render them in software like KeyShot.
Article discussing Meca Bricks:
http://www.solidsmack.com/cad/meca-bricks-brings-an-unlimited-supply-of-lego-to-your-browser/
Meca Bricks' website:
http://www.mecabricks.com/
I have already imported a few models into KeyShot. Looks great!
Neil