"My first experience of film animation was when I was 15 and saw Monsters Inc. When I was watching the main character Mike Wazowski on film I felt emotions for him and suddenly realised there was an animator behind the screen creating those feelings."

Zach Parrish is an artist and head of animation for Disney, working to create characters on films such as Wreck It Ralph, Tangled and Big Hero 6.

So, what does his role as an animator involve, exactly? "A lot of my work is to draw over other people's pictures – telling our animators to change this, adjust that facial pose, body line etc. Most of our work involves drawing straight into the computer. We are essentially sculptors – often having to build a pose in 3D rather than drawing it."

Despite the relatively new emergence of blockbuster animated films, Parrish says he has always wanted to work in animation. "For example, when I was seven years old, a police officer came into school to talk about his job and after the talk our whole class said: 'I want to be a police officer when I grow up!' Instead I said: 'I want to make cartoons!' Everyone looked at me like I had three heads."

Animation is a competitive industry, and Parrish says he was fortunate to get a break straight after university. "I started off by going to a school for animation and, when I graduated, applied for an apprenticeship with animation company Rhythm & Hues. They were working on the Alvin and the Chipmunks film at the time. I was hired as an apprentice for a one month contract. Following that I was promoted to junior animator, and continued to work and build my way up in the field."

Parrish admits every artist has moments when they doubt themselves. "I've had many days like that: times when you come home from work and think 'I should just quit – I'm just a fallacy'. Every artist experiences those extreme highs and lows. But never for a moment have I doubted my love for the magic of animation."

Of course, like every job there are stresses, deadlines and obstacles to overcome, says Parrish. "As cheesy as it sounds the main thing I dislike about my job is that I don't get to work on everything. For example, I didn't work on Frozen as I was busy with other films."

What advice does Parrish give to aspiring animators? "My main advice is to do a lot of it. Keep trying. The phrase I use is 'don't be afraid to suck' because in your student career – in fact in your career in general – you're going to create animation that isn't very good. You're going to hit roadblocks. If you do something bad you shouldn't quit. You have to push through that. As a student I did twice as much animation as I had to so I had double the opportunity to fail – we're all still stumbling along the way."

Practice and failure is key to getting ahead in this field, adds Parrish. "On my website I like to show this by leaving my student work up for others to see. No one starts off as a lead animator at Disney. I suspect even Disney's award-winning animator Glen Keane struggled at the beginning. With more and more graduates looking to get into animation the quality bar keeps going up and up. You have to push through that and keep going."

Ultimately, though, the struggles are worth it for the kudos of seeing your images on the big screen. "It's awesome seeing your work shown to a crowd. When the audience laugh at something animated, something you intended to be funny, it's amazing. You know that they have connected with something you know isn't real. I'm creating that very magic I felt all those years ago watching Monsters Inc."

Big Hero 6 is in UK cinemas now and out on DVD and Blu-ray on 25 May 2015.

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