Even the nearly hour-long climactic battle in Chicago was shot in close collaboration with ILM. "There was very articulate movement around the buildings to get the desired shots, shooting real and adding all the devastation to that," suggests Farrar. "We weren't going to replace all the real buildings with CG buildings. We had to replace them in certain cases. We had a crew that did a technique I'm very excited about where we had a crew of four guys that went back to Chicago and photographed buildings from top to bottom at six different times of the day, hanging from window washing rigs half-way up, shooting spherically. We generate all these stills that can be stitched together and unfolded like a world map to recreate a virtual background for any time of day."

But the mainstay of any Transformers movie is the complex nature of the robots, and Dark of the Moon offered two new ones, each posing different challenges.

Colossus was the most complex asset that ILM has made to date, breaking the previous record by more than 2.5 times. Due to the enormous complexity only a few artists were able to load Colossus and the skyscraper on their machinesAs ILM added more detail and complexity to shots, the most powerful desktop machines it had were barely able to load the data. For those that could, they sometimes waited close to 60-minutes for the files to load, before they could start working.

"We usually have to have multiple versions of the model with different levels of detail, except this one had to be broken out into six different pieces so we could turn off tentacles and tails that weren't in use," explains Scott Benza, ILM animation supervisor. "They would then go in and animate them as a second or third pass."

Then there's Sentinel Prime, the legendary warrior (patterned after Sean Connery, though voiced by Leonard Nimoy). "The design of it allowed us to create a more elaborate rig," Benza adds. "His face has a greater number of plates; and it was more human-like than any of the other robots. With that type of control, we were able to get a more expressive, believable performance out of him."

Bill Desowitz is former senior editor of AWN and editor of VFXWorld. He has a new blog, Immersed in Movies (www.billdesowitz.com), and is currently writing a book about the evolution of James Bond from Connery to Craig, scheduled for publication next year, which is the 50th anniversary of the franchise.