The Harvester serves as McG's giant robot: catching humans as experimental specimens for Skynet.

There's also a liquid throwback to the second Terminator film: The molten metal required a revamp of fluid simulation tools. "Pouring metal on the [T-800] meant that it had to be more precise and make it look like glowing metal," Snow explains. "But some of subtleties of that are lost on the high-contrast treatment of the film. It was more extreme than we had imagined. But to protect ourselves from what we knew was coming, we developed a DI proxy: A high-contrast and desaturation so we would be looking at that on the side. The Terminator factory was a rich environment and so we developed new tools to light that: we took high- dynamic range images, but they weren't moving because of all the sparks going off. But using this approach, you could put a card with filmed elements with sparks on it or take footage from the background and it became a totally correct light source, so we were able to set up a bunch of these little cards and orchestrate them using some software that Pat Conran, our CG supervisor, developed called Layer Cake, [a GL preview], which allowed us to quickly put in spark elements, which then allowed the TDs to be able to dial in something very quickly that matched the complexity of what was going on in the background. We were free to take the classic endoskeleton fight and make it something very modern.

When it came to building the new Terminators, McG definitely wanted them to look and feel more imposing. They include the Harvester, a giant insect-like machine with multiple arms and legs that collects humans; the massive, aerial Hunter-Killers; the sleek, two-wheeled Moto-Terminators (inspired by the Ducati); and the underwater Hydrobot. There are also redesigns for the T-600 and T-800 (originally designed by Stan Winston for the first Terminator). In fact, there is an encounter with the T-800 prototype in the factory utilizing scans of Arnold Schwarzenegger from the original film, according to McG, which ILM then made more photorealistic by creating a new code (as reported by Bob Strauss of the Los Angeles Daily News).

"We created this giant Harvester device, which was McG's robot monster," Snow recalls. "It's got a great visceral reaction, but if [I] were to sit down and decide how I would design a machine to catch humans, I'm not sure that [this] would be my design. But it was great for ILM. We were able to enhance [the original] designs and to take it somewhere different after Transformers and Iron Man."

According to Marc Chu, ILM animation supervisor, "it was fun doing humanoid animation with the endoskeleton, the digital double and then going onto the bigger Terminators. We actually keyframed around 95% [in Maya]. But we also used IMocap technology for the stunt guys to get the interaction with the actors. IMocap continues to evolve; there are less cameras for even a smaller footprint on set. It's very unobtrusive and refined to the point where we can use one witness camera, if necessary. Designers, modelers and creature dev people stepped it up and did a lot of concept work and 3D modeling and teching it out to make every creature in your face, which is what McG wanted."

The sleek, two-wheeled Moto-Terminators were inspired by the Ducati bikes.

Snow says the great thing about pushing these more physically-based and image-based tools is that "it gives you more time to spend on the aesthetic side of the lighting rather than just trying to get an image that looks real. It enabled us to provide the right mood. We're moving past the struggle against it looking CG. We're moving to the point where we can have some fun with it. I feel we need to get our speed up a little bit so we can exploit that [more in the future]."

Bill Desowitz is senior editor of AWN & VFXWorld.