amazing!
Isn't it just so cool-looking? I read a little blurb about the model of the Sydney Opera House made to show the HVAC and plumbing systems in 3D in the time before CAD (computer-aided drafting) in a professional magazine today and was so intrigued I decided to poke around on the internet. Found two-year-old articles on the fascinating history of the model (like this one). Had a harder time finding good pics of the model, but finally found some decent ones here.