©ABC-A, Toei Animation

Real-time rendered animation matches traditional methods for quality on PreCure

Animation has always been a fairly rigid process in which most of the creative for a story needs to be nailed down before you can see final frames. Thanks to real-time technology, that’s all starting to change. By bringing models into a game engine, animators can make tweaks and see the results instantly, while getting a bird’s-eye view of where their work fits into the whole picture.

It’s a way of working that is already starting to win fans—we’ve previously shone a light on how manga artists are capitalizing on the flexibility provided by real-time workflows for creating animated content.

Now, Japanese animation studio Toei Animation and entertainment technology group ARSTECH GUILD (formerly Guild Studio) have teamed up to create animation sequences for Healin' Good PreCure, the latest series in Toei Animation’s popular Japanese TV animation franchise PreCure (Pretty Cure) that revolves around a group of magical girls who battle against evil forces.

Healin' Good PreCure is the seventeenth series in the PreCure franchise, with the first series, We Two are PreCure, airing in 2004. In 2009, Fresh PreCure! included what was to become a mainstay of subsequent series: a fully CG ending sequence of the characters dancing. This style of ending has since become something of a PreCure tradition.
©ABC-A, Toei Animation
For the ending dance sequence of Healin' Good PreCure, Toei Animation wanted to experiment with real-time workflows and find out if it could achieve the look of traditional celluloid animation using 3D technology. With the help of ARSTECH GUILD, not only did it achieve that goal, it also discovered a faster, more intuitive animation workflow—one that removes friction from the creative process.

Achieving the right look using real-time technology 

ARSTECH GUILD’s Art Director Norihide Kakuta previously worked at Toei Animation. Since leaving Toei, he’s remained in contact with the company and has occasionally discussed the possibility of creating real-time movies with them. With this background, Toei decided to bring Kakuta on board to create the ending of Healin' Good PreCure using Unreal Engine for the first time.

“Our aim was to create animation that would be of equal quality to those of other PreCure series, and then re-apply and expand this approach to other platforms such as VR and games in the future,” explains Kakuta. “The challenge was how much we would be able to raise the quality of a cel-look movie with Unreal Engine while using methods that Toei animation had developed.”
“Cel look” is a common Japanese term for an animation style in which 3D images are made to look like traditional celluloid pictures. For this project to be deemed a success, the real-time rendered scenes needed to be indistinguishable from animation created using these off-line-rendered methods. “If our animation could be mistaken for the usual CG of a PreCure series before we revealed that it had been created using Unreal Engine, we would be successful,” says Kakuta.

Before working on PreCure, ARSTECH GUILD had been using Unreal Engine to create video games. The team now found themselves putting the tools they had previously used for game development to use in an animation workflow. Kakuta was in charge of CG production on the project, leveraging Sequencer—the engine’s multi-track editor—to storyboard the scenes. “Using Sequencer is very advantageous,” says Kakuta. “When creating master and shot sequences separately in the video storyboard step, we were able to easily build on our initial animation by updating it later in the process, which was helpful.”
©ABC-A, Toei Animation
©ABC-A, Toei Animation

Empowering animators to work live in scenes

Putting together the real-time rendered scenes for the projects was a collaborative effort between ARSTECH GUILD and Toei Animation. Artists at Toei modeled the characters and props using Maya, as well as recording motion capture. Character models were then passed to ARSTECH GUILD, who optimized them for use in Unreal Engine by modifying UV layouts and packing textures to reduce the number of materials. 
©ABC-A, Toei Animation
The team exported camera data from Sequencer into Maya so that it could adjust movement of characters according to how they looked from the camera's point of view. “The advantage of Sequencer is that we can fine tune the camera while we are reviewing the final look, which includes post processes such as outlines and shaders that are set up in Unreal Engine,” says Kakuta. “That is so useful.”

The team also found the Blueprint visual scripting system useful. Blueprint puts functionality that is usually reserved for developers into the hands of non-technical team members, offering a simplified node-based UI to achieve the same tasks. “Blueprint has a wealth of node-based tools and APIs,” says Kakuta. “The tools are highly robust—we find they are particularly useful for prototyping.”

A virtual environment for remote working

The biggest obstacle the team faced on the project didn’t come from attempting to create animation in Unreal Engine for the first time, but from COVID-19. “Almost at the same time that we started to produce the project officially, the declaration of a state of emergency was issued,” says Kakuta. “Our challenge was that we had to work remotely for the first time to create our first animation work. We were able to get through these hardest days without a huge delay.”

The team adapted to remote working by communicating regularly using Slack and sharing the Unreal Engine project file containing all the shots that were updated daily. “It was helpful that we were always able to set up the same environment by sharing the latest modified data and information within Unreal Engine,” says Kakuta.

Unreal Engine has a number of tools designed to facilitate remote collaboration. These include the Collab Viewer Template, which enables teams to perform collaborative VR and desktop design reviews, and the Multi-User Editor, which brings users on different computers that can be in any physical location into a shared Unreal Editor session, enabling them to collaborate live on building content together.

Over the course of the project, the ARSTECH GUILD team discovered many advantages of using game engine technology to render animation compared to using traditional rendering software. “Unreal Engine dramatically reduced rendering time compared to traditional 3D tools I have used,” says Kakuta. “Taking the color data of one character as an example, four frames of such data can be rendered in one second (with no outlines). This speed would be unthinkable if using traditional DCC software. We had almost no process where we had to wait for the rendering to be completed. So, even if there were defects with materials, we were able to fix this quickly.”
©ABC-A, Toei Animation
This came in particularly handy when shots need to be altered. “It was marvelous that when animation had to be redone, we were able to modify and render it quickly and the changes would appear in the final pictures immediately,” says Kakuta. “This speed is tremendously fast for movie production companies.”

Fast, flexible real-time workflows 

ARSTECH GUILD now has big plans to use Unreal Engine way beyond animation. Kakuta points to the engine’s increasing use for film production as one example of where real-time technology is providing faster workflows and more creative options. “We would like to use Unreal Engine not only for cel-like animation as we did in this project, but also for all other kinds of artistic expression,” he says. 

Back in the animation studio, the flexibility to work directly in scenes, make tweaks on the fly, and see the results there and then mean real-time technology is fast carving out a place for itself in the animation pipeline. What was once a rigid and inflexible process is now much more fluid and versatile. For animators, that means removing friction from the creative process, making it more intuitive—and more fun.
©ABC-A, Toei Animation

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