Optimus Prime is back in Transformers: Revenge of the Fallen for another robot rampage. © Paramount Pictures.

You just knew that Michael Bay was going to escalate everything for Transformers: Revenge of the Fallen -- and he has. There are 46 robots in the sequel compared to 14 in the previous movie, and some of the new ones are bigger and more complicated, with a lot more components and weaponry. In addition, in trying to raise the IMAX stakes after The Dark Knight, Bay decided to shoot the two primary fight sequences using the large format camera, posing more challenges for asset management and rendering.

Of course, Industrial Light & Magic was up for the challenge for doing another Transformers, creating a lot more work in the same amount of time, with Scott Farrar and Scott Benza once again assuming their roles as visual effect supervisor and animation director, respectively. We also spoke with Alex Jaeger, who reprised his role as vfx art director.

"There were a lot of comments from people on the first one that they enjoyed the transformations, so we knew we needed a certain amount of plussed out, easy to read transformations," suggests Farrar, who was also second unit director. "And we knew we had a lot more robots after reading the script -- four times the number as the first movie -- in the same amount of time: about a year-and-a-half. So that was a challenge. It just meant that you have to start the design of each robot sooner. The average robot takes about 12 weeks to build the model and then about another 12-15 weeks to do all of the rigging and, of course, the painting. So we had a huge model staff, we had a huge animation staff; everything was bigger on this film to proportionally get the work done."

Farrar adds that when you factor in all of the assets, ILM reached 60 major builds on Revenge of the Fallen. (Digital Domain worked on a few of the new bots as well, including Alice, who resembles an X-Men mutant.) A favorite factoid: disk storage space was up 150 terabytes from 20 terabytes on the first film. And at capacity they used 95% of the render farm. And the crew hit 350 for the last couple of months.

"One thing that was a major breakthrough was allowing the animators to do most of the motions," Farrar continues. "A big problem for us, up to this point, has been they do some animation, we see it in the shot, the creature dev people, who manage all the pieces on the character, might make a gear move; then they would send it back to animation to plus it out for us. And this back and forth is very tedious. So we arranged everything so there is more control in the hands of the animators. That saved weeks. Another great time savor was the ability to break apart the lighting on each of the robots into various categories (specularity, diffusion). You can render the whole robot with everything baked in, but then you have no control over it later. If you want to fluctuate lights and darks and control that in the hands of the compositors, we can do that with a little bit more disc space, but it gives you room to control the image at a really critical point when Michael wants last minute changes in the lighting.

Director Michael Bay wanted bigger and badder robots for the sequel.

"And we tried to make a lot more efficiencies because this is really tough work on everyone. Our simulations got better (but not smaller). This is the largest simulation project ever at ILM (when Devastator is breaking apart the top of the pyramid). It's colossal! And Devastator is colossal! He has 80,000 parts compared to little bitty Optimus, who's got 10,000 pieces. And Devastator in real world terms is about 150 feet high. And he was in IMAX shots, which are even bigger."

Adds Benza: "We had to raise the bar and to do that Michael's idea was to hit the audience with a greater number of robots and robot types with varying personalities. And we were able to bring a higher level of quality as far as the performances and in the fluidity of their movements."

"This one was about letting the animators do more," Jaeger suggests. "My part was making sure these things have all the detail they need since we have a lot of new characters, making sure that they fit in with our old characters as far as detail and designing all the damage for the robots: keeping together all of the reference -- this part should look like bent metal, this part should look like glass. And not only for the robots but also for the aircraft carrier sequence. That was a huge deal coming up with the look of it and technically all of the pieces involved -- hundreds of thousands of pieces.

"As far as the design, I came up with a lot of new weapons because we had a lot of new Decepticons. Even some of the Autobots. Everything from grappling hooks to guns to rockets.

"The intention with The Fallen [the head Decepticon rival] was to make him more organic to better differentiate him from the others. Another new thing: both Michael Bay and Scott Farrar wanted to introduce the fact that these characters are alive. Drooling and spitting and bleeding and breathing. Rather than mechanical beasts standing around."