Busted! How The Mill helped Mythbusters blow stuff up

Motion control, practical elements and CG came together in a new 45 second promo spot for the Discovery Channel’s Mythbusters show. The promo, designed to represent a ‘frozen moment’ as the Mythbusters crew blow up the Discovery logo, was shot at Kerner Studios and features visual effects work by The Mill in London. We talk to the studio’s executive producer, Luke Colson, and lead 2D artist Hugo Guerra.

Watch the promo

fxg: This promo pretty much sums up the Mythbusters show for me, because it’s all about making experiments fun. Can you talk about the idea behind it?

Luke Colson (executive producer): The director, Ceri Payne, was quite specific that it needed to be one moment in time – the moment that the Mythbusters cast and crew had blown something up in their studios. He wanted the viewer to be completely involved in this one still frame, with the camera weaving around through it. Ceri also wanted a really random assortment of objects, but objects that people who are fans of the show would understand and see the comedy in. It had references to previous experiments. He also wanted it to look colorful and more like an art installation, and more importantly, it needed to look real and have people asking the question, how the hell did they do that?

Layout of the Kerner stage with a map of the moco passes

fxg: How was the spot designed?

Colson: I think Ceri used Cinema 4D to do some basic timings. That meant in our very first meeting we had a visual reference which I think really helped. If you can imagine going in and pitching this idea to a load of people, there would be about ten different ways you could envisage it actually looking. So we then took what he’d done and we started previs’ing ourselves in XSI with the team that would end up working on the project.

The previs helped with the timing, the movement of the camera and how many objects we thought we needed in the final spot to make it look populated to the right degree. This probably took about two weeks – you can imagine that we needed to be absolutely convinced and be totally precise before anyone thought about getting on set. There would have been a lot of margin for error without that planning.

Watch a previs of the promo

fxg: So I understand it was shot at Kerner Studios in San Rafael – what kind of set-up was used there?

Colson: Well firstly we had one of our shoot supervisors, Eric Alba, there at Kerner. He was on another shoot quite nearby. He was able to be there on the day and feed back information as to how things were looking. We were doing calls with him from London while he was on the set. There were two or three rehearsal days and the whole point of it was how many objects we needed in the actual shoot for real and how many we thought we’d be adding or creating in CGI and compositing in afterwards.

The motion control rig and ARRI ALEXA

Hugo Guerra (lead 2D artist): They used an ARRI ALEXA camera mounted on a motion control camera rig. That way we could do multiple passes of the set. It was impossible to make this single movement in one single shot, so we had to split it into different shots.

Colson: We wanted to have a lot of real objects of course, but the problem that posed was that we’d have to clean up a lot of the stands they were on or wires they were hanging from, and also these things could have got in the way of the tracks of the camera. So we tried to find a happy compromise which was shooting about 30 or so of the key or bigger objects for real. Some were on big stands or hanging from wires.

fxg: I suppose one of the more upfront challenges for The Mill then was the amount of rotoscoping you’d have to be doing.

Guerra: Yes, the rotoscoping was a hard task, but we did know that from the beginning. We had to deal with some minor camera shakes and focus as the objects were off in the distance. The cast did a wonderful job of staying still themselves. I can’t even imagine how they did it, but they were very static. There were some movements in the hands and head, and so we had to basically stabilize this piece by piece. We had about ten people roto’ing at the peak of it. All the rotoscoping and compositing was done in Nuke. We used a lot of the 3D features that Nuke has to help with the roto. Since this was a motion control camera, we could get the camera data from the camera and load it up to Nuke, so that helped a lot to make the roto easier.

fxg: Apart from the practical elements there are some 3D objects – how did you decide what would be CG and what would be real?

Colson: It’s kind of funny – Ceri and the producers had this wish list of objects. I think in total there were 130 individual objects, but due to budget restrictions, like on any project, we had to reel that in. So we would literally have brainstorming meetings, maybe two hours at a time, every other day, where we would sit down with the 3D guys and the 2D guys from The Mill, and then all the guys from Discovery and someone would shout out an object and we would say, ‘Yep’ or ‘Nope’. With a bit of research we had a few objects modeled already like tennis balls or bowling skittles in our asset database for re-use.

Above: Props and practical elements being set up for shooting.

We then took the 30 objects out of the mix that would be shot practically. That left about 90 objects, of which we agreed we would be happy to do 30. It was then a painstaking set of choices that the guys at Discovery had to whittle down from the list. Pretty much a day before we had to shoot we had a definitive list of the objects we would be creating in 3D.

Of course the next bit of fun was deciding where these objects were going to go. In the previs, Ceri put circles and arrows across everything and told us where he’d like specific objects – it just evolved from there. It was a good flexible way of working. It certainly grew totally beyond all the realms we envisaged, once we knew how good it would look. I mean, at one point we said we would absolutely not be doing CG liquid out of the fish bowl and no flames on the matches or foam coming out of the fire extinguisher. You can take a look at the spot and you’ll see all those things are in there.\

A video tap roughly combining two of the moco passes

fxg: Can you talk a bit more about how you used Nuke on the promo?

Guerra: There was only a short amount of time to work on this. All the positions of the objects went into compositing in Nuke. We actually had placeholders for the objects in the 2D side. We would import the objects into 3D and they would export them back into Nuke. So there was a lot of camera data and geometry going between XSI and Nuke. Although it’s one single shot, and one single Nuke script, it was worked on by a number of different compositors and then it was glued together basically.

A final shot

fxg: How long did you have to work on it?

Colson: From the point where we had the definitive offline cut, we had three weeks to complete the work. It was 2000 frames long. We got to the point at the end where we would hold these ‘bidding’ sessions where Ceri would say, ‘Any chance of throwing a hat in there? Or another chair?’. And of course we did because we all wanted it to look amazing.


Agency:  Discovery UK Creative
Creative Director:  Robin Garnett
Creatives: Lee Healy
Production Company:  Discovery UK Creative
Director:  Ceri Payne
Producer:  Paul Mortimore
Editing Company:  Discovery UK Creative
Editor: Ceri Payne

Post Production / VFX:  The Mill London
Exec Producer:  Luke Colson
Producer:  Sophie Broadbent
Shoot Supervisor: Eric Alba
Colourist:  James Bamford
2D Lead Artists:  Hugo Guerra
3D Lead Artists:  Jonathan Vuillemin, Juan Brockhaus
2D Artists: Vanessa duQuesnay, Emma White, Georgina Ford, Elena Topouzoglou, Brad Wood
3D Artists: Eva Huehlmann, Patrick Krafft, Florian Mounie
3D Lead Artists: Jonathan Vuillemin, Juan Brockhaus
2D Artists: Vanessa duQuesnay, Emma White, Georgina Ford, Elena Topouzoglou, Brad Wood
3D Artists: Eva Huehlmann, Patrick Krafft, Florian Mounie

Images and clips courtesy of Discovery UK Creative and Eric Alba.