Runway’s Mindblowing Act-One Transforms an Actor into a Cartoon From Just One Video

The AI video platform Runway has unveiled a remarkable new tool that transforms a person into a computer-generated character.

Called Act-One, it takes a video of someone talking — which can be shot on just a smartphone — and uses the performance as an input to create compelling animations.

Traditionally, this type of technology — transposing an actor’s performance onto a cartoon used in films like Avatar — is complex involving motion capture equipment, facial capture rigging, and multiple footage reference. But Runway says it’s their mission to “build expressive and controllable tools for artists that can open new avenues for creative expression.”

“The key challenge with traditional approaches lies in preserving emotion and nuance from the reference footage into the digital character,” Runway writes in a blog post.

“Our approach uses a completely different pipeline, driven directly and only by the performance of an actor and requiring no extra equipment.”

Act-One can be applied to a wide variety of reference images including cartoons and realistic-looking computer-generated humans, essentially deepfakes.

“The model also excels in producing cinematic and realistic outputs, and is remarkably robust across camera angles while maintaining high-fidelity face animations,” says Runway. “This capability allows creators to develop believable characters that deliver genuine emotion and expression, enhancing the viewer’s connection to the content.”

Runway says that users will be able to create high-quality, narrative content using nothing more than a consumer-grade camera and one actor reading lines. The actor can even play different characters.

Act-One has begun rolling out to Runway users and will soon be available to everyone.