INTERVIEW: John Nelson - I, Robot

I, Robot effects supervisor John Nelson talks to Matt Chapman about bringing the future to life...

How much of the movie was made using visual effects/CGI?
There are in the whole movie 2,080 shots if you add up every cut, and 1,060 of them are visual effects shots. That means one out of every two shots is a visual effects shot. It took 16 months of my life to do all the effects work.

Does having that many effects interfere with the audience’s enjoyment?
When you look at it, I’m sure no-one will notice a lot of the effects work, in that it goes by and it’s just a set that didn’t really exist, but it looks photo real. This film is set in Chicago but we never really filmed there except for aerials. We went to Chicago and shot stills and did lighter skins of buildings. So whenever you’re on the street in Chicago, you see all these identifiable Chicago landmarks, it’s all been put in using visual effects. Most people get that the robots are visual effects, they see the robot and they say well that has to be a visual effect because they can’t be done. But very few people can put together that the street is CG, the building behind the trucks is CG, the bridge that the trucks are standing on is CG, even down to the stanchions on the bridge. It’s a virtual world.

When you were researching your work, did you study robots from other movies?
Our most important thing was to provide an emotional performance for our lead robot. It was where we differed from robotic performances of the past. We looked at them all and, number one, usually it was a guy in a suit or a human playing a robot. We really wanted the robot to play the robot, even though we debugged that with a human performance as a proxy for it. Number two, we felt that previous cinematic robots had never really gotten an emotional connection to the audience, and we wanted to definitely get that connection.

Is it all CG or do you use more traditional methods?
We destroyed this house that Will was inside of, and destruction is sometimes best done with a model. So we did it with a third-scale model. We have the robot waking up, turning around, it was sort of like a transformer. And then once it starts going in, we filmed the destruction of the model on the outside with CG in the foreground. How we did this was we shot Will on a set we could elevate up in the air and actually shake. Then we had a third-scale miniature behind it, that we bled into it. So you put those things together, then we added tons more debris, and put CG volumetrics shooting through that debris. We blended it all together and for good measure shook it in post shake to make it even more violent.

Which effects do you like the most?
We loved grinding robots in this movie, that was one of our favorite things!

Does working with CG give you any advantages?
One of the car scenes uses a CG windshield, which means the camera can pass straight through it. Some scenes are completely digital – tunnel, trucks, car, even Will inside the car. We used a lot of digital pyro and that’s unusual for a movie in that most of the time it’s a real explosion. But we felt that it was appropriate for this.

Did you work on the design as well?
The production designer was also the creature designer, so that ship had sailed by the time I got on the movie. But there’s a lot of design that’s really interpretive, where the designs might be two drawings but you need to generate a 10-minute sequence from that.

How difficult was it having an actor – a proxy – playing the robot and then turning it into CG?
It was very difficult but whenever there was physicality that was real we would always do it with real physics. So if someone were to shake a hand or hand over a paper they’d really do that, or if there was a fight and they’d be pushed, they would really be pushed.

What was the hardest shot in the movie?
The scene in the holding cell where Sonny goes “I did not murder him!” You had slow pushes moving in on Will and the robot. Action beats are easier because they’re faster. Don’t get me wrong, they’re hard but addressable! Performance is like catching lightning in a bottle. You ask “Why doesn’t it work well? OK let’s try this”. You can look at nose flutters or brow furls but really it’s an emotional thing. It’s like pulling a performance out of your guts.

Buy I, Robot on DVD at Amazon.co.uk or Amazon.com