I just came across this plug-in for sketchup to output an stl file which is the required import format for ecabs. Haven't tried it yet, but it may be a way to create inputs for ecabs without a full fledged CAD package.
Hi Glenn, I mentioned in a post a little while back that I was converting .skp files from the 3D warehouse. It is easy to do in the display part editor. It is only use ful for developing your library of display objects. If you want to play with the rendering you will need a CAD package that can break the SKP into parts which you can then render and pull together in the Display part editor