I remember kind of doing early acting and thinking, "God, they don't paint behind the sets." It's a bit of a shame, really - "Oh, what's on the other side of this wall? Oh, you can see the plywood." I was really disappointed. I just thought that these things were real, from watching things as a kid.

When I played Gollum in 'Lord of the Rings,' if I was climbing up the side of a mountain, which I physically did, you know, I was on every single occasion swimming through streams, all of that, that wasn't captured. That was filmed on 35 millimeter, and for certain of those shots, it was rotoscoped and painted over.

Performance capture is a tool that young actors will need in the next 10, 20 years. It's on the increase, as you say. It's not going away.

There's this whole grey area seemingly every time it's talked about animators and who takes ultimate responsibility for the characters [of the Planet of the apes] but without question and I'll go down saying this year after year, these characters are authored by what we do on set. They are not authored by animators.

My first job when I got my equity card was acting in 14 plays back-to-back. Playing that many roles, you look for ways of differentiating the characters physically, which goes hand in hand with understanding them psychologically.

That's why I ended up going to Lancaster University, because they had a visual arts course, and in the first year it was like a broad visual arts course in sculpture, painting, graphics - all of that.

But that's not what an actor does. An actor finds things in the moment with a director and other actors that you don't have time to hand-draw or animate with a computer.