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CGI Thomas & Friends Director


Greg Tiernan answers our questions on his involvement with the current CGI production of Thomas & Friends!

Nitrogen Studios, headed up by husband and wife team, Greg Tiernan and Nicole Stinn, have been involved with the production of Thomas & Friends since 2008, initially providing CGI elements for the final live-action model shoot, and currently helming the production of the full-CGI series and associated specials.

Although initially met with scepticism and wariness prior to their debut, the work that the Nitrogen team have ploughed into the series has been incredible, and the visual element of Thomas & Friends is now stronger than ever before, with a new world of opportunity lying wide open, and driving the sales for the series further than ever before.  

SiF have met Greg and Nicole twice at Thomas & Friends premieres and we have nothing but praise for them and what they do.  As Greg is dedicated Rail-Fan and a Railway Series enthusiast himself, we feel that HIT Entertainment could have made no better appointment to helm the new CGI series.

We hope you enjoy the insights that Greg provides here, and thank him, Nicole and the entire Nitrogen team for their continuing contributions to Thomas's world, and wish them all the best for future!

~ with Ryan Hagan, March, 2011

DISCLAIMER: All answers and opinions expressed in this interview are solely those of Greg Tiernan, and in no way purport to represent those of HIT Entertainment/Mattel

Nitrogen Studios were founded in 2003, and given the quality of work produced there, one would assume yourself and Nicole have gained a great deal of experience working for other people first.  Where did you both gain your experience, and have you worked on any projects of great note?

I have worked in the animation industry for 26 years and with Nicole for 19 years.  I have worked in Ireland, the UK, Germany, the US and Canada, and Nicole has worked in the US and Canada. We have worked on all sorts of projects ranging from theatrical feature films (both animated and live action) and TV series to animated commercials to Video Games and CD ROMs. We have been involved in many notable projects. Movies include: An American Tail, The Land Before Time, All Dogs Go To Heaven, Cool World, Tank Girl, The Tigger Movie, Mr. Magoo, Rugrats in Paris, The Wild Thornberrys Movie, Bionicle and many others. TV commercials for major clients like Nike, Coca-Cola, Hasbro and NBC TV, and TV series in the UK and US / Canada like Danger Mouse, Rugrats, The Brothers Grunt and others. Video games like Sony's God of War, and many Disney titles for cartridge and CD ROM games based on features like Tarzan, Hercules, Pocahontas, The Hunchback of Notre Dame, and The Lion King.

We’re all aware that Nitrogen Studios provided some of the CGI animation for the 2007 Feature Film, Happily N’ever After, what other major productions have the company been involved with?

Lots of projects....Thomas & Friends, of course, the Sony AAA video game God of War, video games based on Pixar's The Incredibles and a Sonic the Hedgehog Nintendo DS video game, we storyboarded the DVD movie Bionicle: Web of Shadows, provided the animated titles for four Roxy Hunter live action movies, we provided storyboards and animation for TV shows in Canada and the US like Jacob Two Two, Max and Ruby, Yo! Gabba, Gabba, Da Boom Crew and MP4orce....animation for Jerry Seinfeld / American Express online Superman commercials...and many more projects.

Can you tell us how and when Nitrogen first became involved with HiT Entertainment and Thomas?

We were approached by HIT Entertainment in 2007 when the decision was being considered to switch producing the show in live action to CG animation. HIT was aware of our career history and the capabilities of our studio. We provided test shots to HIT to see how the show could look with CGI added to live action footage (as eventually seen in Season 1200). We also provided a short sequence of full CGI. Based on the overwhelmingly positive feedback to these tests from focus groups and from broadcasters, and despite the understandably cautious reaction from the show's older fans the decision was made to make the transition. We are delighted that HIT chose our studio as the new 'home' for Thomas.

How familiar were you both with Thomas’ world beforehand?

We both were very familiar with the world of Thomas before this. We were always very impressed with the original TV show and had read the Reverend Awdry's Railway Series books when we were younger. Of course, once we were part of the show’s production, we went into overdrive in our research and read all of the Railway Series again and re-watched every single episode of Thomas & Friends from Season 1 to the present. We also compiled as broad a reference library as we could get our hands on...everything from The Thomas the Tank Engine Man and The Island of Sodor to Industrial Steam in the 50s and 60s and Two Centuries of Railway Signalling. We never approach anything in the show without fully researching historical accuracy first.

Very early on, it appears to us that the model episode from Series 11 -“Thomas and the Stinky Cheese” was adapted to a CGI’d version. Was the CGI’d version used to garner and gauge test audience feedback, and is there anything else you can tell us about it?

Yes, that is exactly what it was used for. We reproduced a short sequence from “Thomas and the Stinky Cheese” as a way for everyone to see what Thomas & Friends could look like in CGI. Although it proved extremely successful, we have to confess that our work looks primitive compared to the show as it exists now!


Can you explain the process that was used during the CGI animation of Series 12? We are aware of the targets being used for the faces, but how did these work?

A standard procedure in the industry, when combining CG animation with live footage, we added tracking markers to live shots so that once the animation is added, it doesn't jitter around, and it stays 'locked' to the movement of either the actor or the camera pans in the live action picture.

Because our primary task was adding faces to the engines, the most appropriate place for a tracking marker was on the face plate of the engines with the actual faces not being needed. Adding the markers to the faces served two purposes -- the first was to enable the moving engine to be tracked. For the second, since we would be covering the markers with our CGI faces, this eliminated the costly and time consuming process of digitally removing the tracking markers from the final shots.

The Shepperton crew shot the show as usual, except with the addition of tracking markers. We then took the image sequences of the entire show and ran them through our pipeline and used software to read the tracking markers in a process known as match moving. Every TV show and theatrical movie which combines live action with CGI visual effects uses this process. The result is that our CGI faces appear to be locked firmly in place on the engines no matter where they moved or no matter where the camera moved.

Were there any great difficulties present when fusing the two animated mediums of live action models and CGI together?

There are always a few tricky problems to solve when combining live action with animation. I should point out, at the risk of sounding pedantic, that the original model shoot is not and never was animation. Everything was shot in real time. The two biggest challenges are making sure that the CGI stays locked to the live action footage, and that the lighting that we used with our CGI models matched as closely as possible to the lighting used on the set. We managed the latter with the use of a mirror ball, a common industry technique, which enables the CGI production house to accurately measure the colour values and intensity of the lights that were used on the set and then recreate them in our CGI set.

How much interaction did you guys get with the model unit at Shepperton throughout that particular shoot?

We were in constant contact with the Shepperton crew, and I was on set for the first week of shooting Season 1200 at Shepperton to help the crew set up the necessary additions to their shots.   I consider myself extremely fortunate to have had the chance to work with such a fantastic crew and to work on set for part of the final days of such an iconic show at Shepperton.

When the decision was taken toward the end of Series 12’s production to change over to full CGI, how did you and your team feel about taking over from the established medium of 25 years?

An overwhelming sense of pride and honour, tempered with sheer terror! Our initial feeling, contrary to all good business sense, was that it was a shame to change Thomas from its traditional method of production. We strongly felt that if this was to be the future for the Thomas TV program, then we were the only studio who would treat Thomas & Friends with the respect that the show deserved. We wanted to shepherd Thomas into his new format with as much care and reverence to his roots as possible.

We would like to give a very special word of thanks to Steve Asquith and Simon Spencer who were the epitome of professionalism and good grace in handing over the torch to Nicole and me as the new Producer and Director. We try every day to follow on from their example, and that of Britt Allcroft and David Mitton, in our efforts to produce a show of which the Reverend Awdry, were he alive today, would be proud.

It also should be noted that HIT Entertainment has been the best production partner that we could have hoped for and has been extremely supportive of our efforts at every step of the way.

Many fans are curious about how Thomas and his Friends were transformed into CGI so faithfully from their model counterparts. Would you be able to elaborate as to how the transformation took place? A friend of SiF who had worked on Thomas and the Magic Railroad suggested that a 3D Color Laser scanner may have been used to initially digitize the models.

The models are recreated from scratch without any scanning or programming, just good old fashioned craftsmanship! Our modelers work from the original models, many of which we have on display in our studio, and from hundreds of photographs of each engine -- both the show model and the engine on which the character was based.

Each model is hand sculpted in the 3D animation program Maya (industry standard software). I say 'hand sculpted' because there is a common misconception that because computers are used for 99.9% of production in the animation and VFX industries that it is the computer itself which is doing the work. Nothing could be further from the truth. The computer is no more than a tool. Our modellers work in way that is very similar as to how the model makers worked at Shepperton when crafting the original models, and very similar to how sculptors work with clay, except our modelers do their crafting within Maya.

Every detail of the original TV model is carefully reproduced in the CGI model. We have many rounds of review between the modeller, the modelling supervisor and myself before we submit the model to HIT for final input and approval.

Nitrogen had the arduous task of producing full CGI sets and models prior to beginning and completing production of a series and special in little over a year. Was it a particularly difficult job getting everything together in time?

It was a task of gargantuan proportions and one which is ongoing. In order to recreate Sodor in CGI, every facet of the original show had to be recreated including every building, vehicle, prop and character. That's hundreds of thousands of individual assets!

Our initial task was to create enough assets to get stories underway and give a believable setting to these stories. As each season progresses we've added more and more of both classic Thomas destinations and characters as well as new ones, but it will be quite a while before every familiar set and character are recreated in CGI.

Do Nitrogen have a map of their sets and is there a particular order to them, or do locations appear on a required basis to provide vehicles for the characters?

We have a map of our locations and everything is based on the original map of the Island of Sodor. We place a compass in every set and scene so that our geographical position is always correct. There is no particular order to the appearance of these sets on screen -- we can pull them up at anytime, for any story. It's basically the story points of each episode which dictate which set is used.

Back in the Series’ model era, whenever Production would plan to introduce a new character, Dave Eves would suggest a real engine prototype to suit the character’s personality and have his model crew build it from the wheels up. Would you be able to share how the process works now in a 100% CGI character environment? Say, using “Charlie” as an example? Is there a lot of research that takes place? (old photos, proper scaling, technical drawings etc?) And is it more difficult than using the old models?

We follow exactly the same process, except that it is myself who suggests the engine prototypes in response to HIT's needs for the show. We always do exhaustive research on the engine that is the prototype for every potential character, and this involves collecting all of the available photographic, video and written reference. Whenever possible, we travel to museums and preservation railways in the UK to photograph, film and see these engines in real life.

We add as much realism as possible whilst staying within the artistic boundaries of the style of the show.

Are there any characters or locations from the model era that you would particularly like to return to the series? Will we ever see any of the old characters - Boco, Donald & Douglas, Duke, and so on and so forth, return?

Speaking from purely a personal point of view, we would like to see every character return. I wouldn't discount seeing some of your old favourites again in the future.


Now that the CGI format has been established and accepted by the fans, is there room for you to be more brave with changing things up such as reintroducing older locations and set designs to give a larger sense of continuity to the show?

We have been very brave in introducing both new characters and new locations on the Island of Sodor. As stated previously, we are working hard to recreate Thomas’ entire world into CGI – both classic locations and new, and this will take some time.

What modelling software do you guys use to create the scenes for the show?
We use a primarily Maya pipeline with various support software.

Is directing a 100% CGI episode just as much work as a “live” production i.e. with models? Is the method very similar?

It is a very similar process, except that with animation, we have to pre-edit. We need to plan our shots ahead of time by storyboarding and putting together a low resolution previz reel. Examples of this can be seen on the Nitrogen website. In live action, all of the editing is done after the footage has been shot. To do that in animation, it would be way too expensive as there are areas in animation which are far more time consuming and labour intensive than in live action production. Shots which end up on the cutting room floor in live action are relatively inexpensive when compared to the same shots of an animated production.

The main goal with directing a Thomas episode is the same whether in CGI or live action – to craft the most engaging story as possible from the script that you've been given.

Is there a vision of the show that you have, that you are trying to evolve the current one into?

My personal vision is that I'd like the show be as competitive in today's pre-school TV marketplace as possible whilst keeping as much railway realism and Reverend Awdry influence as feasible. The current show has the best production values of any pre-school show anywhere in the world, and Thomas & Friends will continue to enthral not only children, but also adults for many years to come. If we can play just a small part in keeping Thomas' legacy on track, we'll be happy.

Will we see brake vans on trains soon? Please can we have trucks with faces back?

Keep watching the show and you may be pleasantly surprised

We know Greg is a fan of the Railway Series, he mentioned that he had a copy of The Island Of Sodor, and we’ve seen Peter Edwards’ Island of Sodor map crop up in Misty Island Rescue. Would you say you’re trying to add some of the original Awdry influence back in subtly to the TV Series through what we see in your visuals?

Absolutely. I've always been a stickler for authenticity, and I firmly believe that you can never do enough research. I will always refer back to the Reverend Awdry's perspective of Sodor as this is the foundation on which the world of Thomas is built.

Do you have any particular favourite stories or characters from the original Awdry books at all? And if we had an ideal world, and there was an opportunity at hand to create an episode from the original books in CGI form, which would you choose and why?

I like all of the original Reverend Awdry stories, but I have a particular soft spot for Devious Diesel and the engines of the Skarloey Railway. I would love to recreate "Pop Goes the Diesel" and "Dirty Work" simply because Diesel is such a wonderfully classic antagonist. There is so much in his personality that has remained untapped. It’s a great well to draw from in his role as a troublemaker. A happy by-product of these stories is that they include dear old Duck and the Troublesome Trucks.

I have always loved "Very Old Engines" and "Duke the Lost Engine". I have a lifelong passion for history and adventure stories, and both of these Awdry books deliver history and adventure in spades.

As a Rail Fan, are there any particular locomotive designs you would love to see brought to life and animated as a new character in the series?

It's probably a lame answer, but there are so many fantastic engines throughout the history of both steam and diesel (not to mention electric) that it's often quite difficult to decide on a particular design. I'm particularly drawn to 'unusual' designs – for example, the industrial Sentinels like Scruff, and Den, who appears in the upcoming Day of the Diesels. It would be great to have a fireless engine at some stage, and a big ol' Beyer-Garratt 2-6-2+2-6-2 would be wonderful...but impractical for Sodor!

I imagine that you receive many résumés from hopeful animators – several who are undoubtedly Thomas fans and would love to contribute to the show. What would be your best advice to someone starting out or contemplating a career in animation?

We do receive a lot of resumes and reels from artists who would like to join our crew. The best advice that we can give is that potential animation artists (there are dozens of job categories other than animators) should immerse themselves in as much animation reference as they can. They should study the classic films of Walt Disney and the Warner Brothers and MGM cartoon shorts; Study British, European and Asian animation as well as making themselves completely aware of current trends in the business with the movies of Pixar, Sony, Disney, Dreamworks, etc.

They should then ask themselves if, really and truly, they feel that their talent is of such a calibre that they can step into the arena with the professionals. And if so, go for it!

It's important for artists new to the industry to realize that talent will always win out over qualifications on paper. Recognizing the limits of that talent is the key to gaining acceptance at a studio. Animation is a highly skilled profession and takes years of hard work to master. As a talented young artist myself (Long ago!), I was shocked at how much more talented than me was pretty much everyone else that I came across during my first few years in the industry. I knew enough at the time to learn from those around me and to be open to criticism and advice from my peers and senior artists. Twenty-six years later, I'm still learning.

Are you excited about working on upcoming features and seasons?

Yes. We are very excited at the prospect of working on upcoming seasons. We hope to be involved with Thomas for as long as possible.

Finally, are there any messages you’d like to pass on to the long time fans of the series?

We'd like the long time fans of the show to know that we very much appreciate their dedication and respect for Thomas & Friends. We at Nitrogen hope that our efforts are worthy of their expectations for their favourite show. We'll continue to do the best that we can for Thomas, for HIT Entertainment, and for Thomas' fans.


SiF would like to extend a gracious thank you to Greg Tiernan, Nicole Stinn and the team at Nitrogen Studios for this interview, as well as for their tremendous creative input into the series as a whole - you're doing a great job guys, we're loving the visual side of Thomas at the moment!


The Nitrogen Studios playlist takes you through examples of work that the production company have been working on.  From new pre-school property, Kodee's Canoe, through the Thomas & Friends showreels, to advertisements for Gretsch Guitars, and examples of their Flash animations, finishing with CGI work done for the movie, Happily N'ever After!

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