The CGI Series refers to the television series as it was produced from the twelfth season onwards. In 2008, HiT Entertainment announced that Thomas and Friends would be undergoing a radical change in production. The company announced its intent to relocate production of the series from the United Kingdom to Canada. With this change, HIT announced that future Thomas productions would be animated with Computer-Generated Imagery.
HiT Entertainment's Senior Vice President of Production and Programming, Christopher Skala, stated that the change, aside from budgetary reasons, was intended to convey more emotion and flexibility through the stories. Skala claimed that, of his focus group, even those who felt that Thomas, as an institution, should not be changed in this way ultimately responded positively to the demonstration of the new animation techniques.
As part of a transitional period, the twelfth season would see computer-animated faces and characters superimposed over the live-action environment of earlier seasons. Characters could now display a variety of new expressions and their mouths would move in sync with the storyteller's voice when they are talking, whilst their thinking is evident when their mouths aren't moving in sync! People, animals, and certain other characters became wholly CGI elements.
This change was made possible by motion-capture animation. When a character's face needed to move, the moulded faces of earlier seasons would be replaced by a target, to which the computer could attach a face in post-production. The animation for this and future seasons would be provided by Nitrogen Studios, based in Canada.
- The first season to have only twenty episodes.
- The first season to use CGI elements.
- The last season to use models and clay faces.
The first feature of the overhauled series was Hero of the Rails, released in autumn 2009. Trailers, DVD covers and a music video called Go, Go Thomas all from this feature-length special were shown on YouTube prior to its official release. Book merchandise tying into the special have also appeared on online retailers. It introduced three new characters and a new location - the Sodor Steamworks.
- Victor, a red tank engine who is in charge of the Sodor Steamworks.
- Kevin, a yellow four-wheeled mobile crane who belongs to the Sodor Steamworks.
- Hiro, an old Japanese engine, whom Thomas helped restore.
- The first production using entirely CGI animation.
The thirteenth season was the first season to feature computer-animation exclusively. Two images were originally found - two recreations of scenes from the eleventh season episode Thomas and the Stinky Cheese.
- The first appearances of Bertie and Troublesome Trucks in a full CGI. Trevor appears in the "Island of Sodor" opening sequence.
- Billy was supposed to appear in the thirteenth season, but he was replaced by Charlie, likely because of the change from models to CGI.
Misty Island Rescue is a special that was released on September 7th, 2010 in the US and October 11th in the UK.
- Captain, a brave lifeboat.
- Bash and Dash, mischievous grey and yellow tank engine twins.
- Ferdinand, a teal class C Climax.
- The first appearances of Diesel 10, Harold, Salty, Whiff, Stanley and Butch in a fully CGI environment.
The fourteenth season is the second to use CGI exclusively. It began airing on October the 11th, 2010 in the UK and in November in the US.
The fifteenth season is the third to use CGI exclusively. It began airing on March 1st, 2011 in the UK and on April 2nd in the US. The twenty episode season was supposed to air after the release of Day of the Diesels, but was brought forward for unknown reasons. Because of this Belle, Flynn, Dart, Den, Paxton and Norman make their first appearances in the series. Although it was their first appearance, they would not officially be introduced until Day of the Diesels. Rupert Degas also joins the voice cast.
- Butch spoke for the first time.
- The first speaking roles of Bertie and Stanley in the CGI series.
- The return of Arlesdale End, Castle Loch, the Fishing Village, and Wellsworth.
- The first appearance of Trevor in a CGI episode.
- The first appearance of the Sodor Dieselworks.
- Sir Handel, Peter Sam and Duke were going to appear in the fifthteenth season episode, Kevin the Steamie, but their roles never made it passed the storyboard stage.
- Sidney, a forgetful and absent minded shunter.
Characters officially introduced:
- Belle, a blue tank engine with a brass bell and water cannons.
- Flynn, a road-rail fire engine who joins the Search and Rescue Team.
- Den, a stately Diesel who works at the Sodor Dieselworks.
- Dart, a clumsy Diesel who works with Den at the Sodor Dieselworks.
- Norman, Dennis' twin.
- Paxton, a gullible shunter who likes steam engines.
The sixteenth season first aired in February and March 2012 in the UK and April and June in the US. Steven Kynman joins the voice cast as Peter Sam (albeit uncredited in the UK broadcast) and William Hope is added to the UK voice cast for the first time. This was the last season animated by Nitrogen Studios.
- The first appearance of Skarloey, Rheneas, Sir Handel, Peter Sam, and Rusty in a full CGI episode. Duncan was also mentioned.
- The return of Skarloey Railway Depot, the lighthouse, the Sodor Suspension Bridge.
- The trucks appear with faces for the first time since the thirteenth season.
- Stafford, a wooden battery-electric shunting engine.
- Winston, a red track inspection vehicle belonging to Sir Topham Hatt.
Owen and Merrick both cameoed in The Christmas Tree Express.
Blue Mountain Mystery is a special that was released in 2012. The Skarloey Railway engines feature heavily. Michael Legge joins the voice cast as Luke and David Bedella takes over the voice of Victor in the UK dub, taking over from Matt Wilkinson. This was the last special animated by Nitrogen Studios.
Characters officially introduced:
- Winston, a red track inspection vehicle.
King of the Railway is a special that was released in September 2013. This special marks the return of Jack. Bob Golding and David Menkin joined the voice cast, although the latter went uncredited. Four of the new characters were first seen in the seventeenth season. This is the first special animated by Arc Productions.
Characters officially introduced:
- Sir Robert Norramby, an Earl of Sodor.
- Millie, a light blue tank engine.
- Caitlin, a pink-purple streamlined tender engine.
- Connor, an aquamarine streamlined tender engine.
- Colin was originally going to appear in King of the Railway, and concept art of the film by Guru Studios shows that he would have been based at Ulfstead Castle.
The seventeenth season started airing in June 2013. This season is the first to use a new writing style for the series and is also the first animated by Arc Productions. As ten episodes of this season were released ahead of King of the Railway, this season marks the first appearances of Millie, Connor, Caitlin and Sir Robert Norramby and their voice actors Miranda Raison, Jonathan Forbes, Rebecca O'Mara, and Mike Grady respectively. Although this is their first appearance, they would not be officially introduced until King of the Railway. Rupert Degas also left the series.
- Mark Moraghan takes over narration duties from Michael Angelis and Michael Brandon.
- The first appearence of Duck, Bill and Ben, and Harvey in a full CGI season.
- Diesel 10 and Sidney also appear in an episode for the first time.
- The return of Kellsthorpe Road, Dryaw and Crowe's Farm Crossing.
- Jonathan Broadbent also joins the voice cast and Teresa Gallagher takes over the role of Mavis in the US version.
- Porter, a confident dockyard shunter.
Tale of the Brave is a special released in September 2014. It was the second special to feature animation from Arc Productions. Clive Mantle and Olivia Colman joined the voice cast as Gator and Marion respectively.
- Timothy, an oil burning engine who works for the China Clay Company.
- Marion, an eccentric steam shovel.
- Gator, a steam engine with a sloping boiler who resembles an alligator.
- Reg, a scrapyard crane.
- Samson, an overly confident saddle tank engine.
- Slip Coaches, a set of coaches that used to belong to Duck.
- Oliver, Toad and Duncan return.
- Henrietta appears for the first time in the television series with a face.
- Crovan's Gate, Sodor Castle, Rheneas Viaduct, the Woodland Way, and Glennock return.
- Maggie Ollerenshaw (as Henrietta), Tim Whitnall (as Reg), Tom Stourton (as Duncan), Joe Mills (as Oliver and Toad) and Robert Wilfort (as Samson) join the voice cast.
The Adventure Begins is a forty-four minute special that was released in March 2015 in the US and July 2015 in the UK.
- Judy and Jerome, the breakdown train used to rescue James.
- Glynn, one of the Fat Controller's "coffee pot" engines.
- The Breakdown Train gains faces and names.
- Ffarquhar station returns in full CGI.
- Rob Rackstraw (taking over the role of James in the US), Christopher Ragland (taking over the role of the Troublesome Trucks) , John Hasler and Joseph May (taking over the role of Thomas in the UK and US respectively) join the voice cast.
- The first time since the fourth season that Railway Series stories have been adapted for the television series and the first time the North Western Railway has been referred to by name.
The nineteenth season began airing in autumn 2015, and was the third season animated by Arc.
- Philip - an energetic little boxcab diesel
- Nigel Pilkington (taking over the role of Percy) and Rasmus Hardiker (voicing Philip) join the voice cast.
- Rob Rackstraw takes over the role of Toby in the UK.
- Lord Callan returns.
- Trevor's first appearance since the fifteenth season.
Sodor's Legend of the Lost Treasure was the 2015 special.
- Mike, a red tender engine working on the miniature railway.
- Rex, a green tender engine working on the miniature railway.
- Bert, a blue tender engine working on the miniature railway.
- Ryan, a purple tank engine who arrives to help build a new line.
- Skiff, a railboat formerly owned by Sailor John.
- Sailor John, a sailor obsessed with finding buried treasure.
- The Arlesdale Railway's first appearance in the television series.
- Donald, Douglas, Daisy, Alfie, Max, Monty, and Oliver the Excavator returned in full CGI.
- Jamie Campbell Bower and Nathan Clarke join the voice cast. Eddie Redmayne and Sir John Hurt also appear as guest stars in the film.
- Robert and Peter Hartshorne step down as composers for the series.
The twentieth season began airing in 2016. It is the fourth season and final season to be animated by Arc before they were purchased by Jam Filled Entertainment after filing for bankruptcy. Jam Filled completed five episodes of this season.
- Bradford - a brake van
- Hugo - a rail zeppelin
- Captain Joe - Skiff's new captain
- Fergus Duncan - the controller of the Arlesdale Railway
- Tracy-Ann Oberman joins the voice cast, and assumes the role of Daisy from Teresa Gallagher.
- Trevor's first speaking role since the ninth season.
- Jeremy's first appearance since the twelfth season.
The Great Race is the 2016 special.
- Ashima - a brightly coloured Indian engine.
- Vinnie - a Canadian tender engine
- Axel - a streamlined Belgian engine
- Shane - an Australian tender engine
- Yong Bao - a Chinese engine
- Gina - an Italian tank engine
- Etienne - a French electric engine
- Rajiv - an Indian tank engine
- Frieda - a German tender engine
- Raul - a Brazilian shunter
- Ivan - a Russian shunter
- Carlos - a Mexican tender engine
- The Mainland Diesels - a group of shunters who shunt trains for the contestants
- Vicarstown Station appears in the television series for the first time.
- Flying Scotsman returns in full CGI in his first proper role.
- Tina Desai, John Schwab and Rufus Jones join the voice cast.
- Chris Renshaw takes over as composer of the series.
- The last special animated by Arc Productions.
Season 21 began airing in September 2017. It is the first season to be animated by Jam Filled Entertainment.
- Hannah - a new coach who temporarily replaces Henrietta.
- Carly - a new, shiny crane at Brendam Docks.
- Nicola Stapleton joined the voice cast.
- Rosie received a new permanent livery.
- Big Mickey received a face and the ability to speak.
- Terence, Bulgy and Farmer Finney returned.
Journey Beyond Sodor is a special released in 2017.
- Beresford - a rolling gantry crane
- Theo - an experimental railway traction engine
- Lexi - an experimental cab-forward tender engine
- Frankie - a diesel shunter
- Hurricane - an experimental tank engine with ten driving wheels
- Merlin - an experimental tender engine fitted with three stovepipe chimneys
- Single Ventilated Vans and Oil Tankers have faces.
- Salt Vans and standard gauge Slate Trucks are reintroduced with faces.
- The first time the Mainland diesels have spoken, however, only two of them speak in this special. In addition, one of them is named Ulli.
Big World! Big Adventures! The Movie is set to be released in 2018.
Season 22 will begin airing sometime in 2018. It is the first season to go under a different name, being Big World! Big Adventures!, and will mark the first major "reboot" of the show since the switch to CGI in the thirteenth season.
- Rebecca - a Bullied Pacific tender engine