[Culture Interview] "AI Can Create Images, but Emotions Are the Actor's Domain"... Han Woojin's Challenge After Playing 30 Characters

Han Woojin, the second motion-capture actor to walk the red carpet at Annecy
Heo Beomuk’s final film, “The Pig That Came Back Alive from Foot-and-Mouth Disease”
“The eyes make up half of facial acting, from the pupils to the space between the eyebrows”
“Real actors are essential to advancing AI-generated video”

Motion-capture actor Han Woojin performs a character in "The Pig Who Came Back Alive from Foot-and-Mouth Disease" / Courtesy of Hanniverse.

Artificial intelligence (AI) is lowering the barriers to video production, but some things are difficult to achieve with technology alone: the emotions and breathing woven into a person’s movements. A motion-capture actor who played 30 characters by himself in a single film has taken note of this potential and launched a startup. His vision is to combine AI with actors’ performances to improve production efficiency while preserving characters’ emotions and directors’ intentions.

“Technology can create dazzling, intricate images, but the emotions and breathing within them ultimately come from the actor,” Han Woojin, CEO of Hanniverse, said in an interview with The Asia Business Daily. “Better content can be made when AI is added to real performances.”

Han performed the movements of all 30 characters in “The Pig That Came Back Alive from Foot-and-Mouth Disease,” the final film by the late director Heo Beomuk. The film was invited to the 2024 Annecy International Animation Film Festival, where Han also walked the red carpet as a motion-capture actor. He was only the second after Andy Serkis, who played Gollum in “The Lord of the Rings” and Caesar in “Planet of the Apes.” The experience laid the groundwork for him to establish Hanniverse, an AI content startup focused on acting, in February.

Still from the film "A Pig That Survived Foot-and-Mouth Disease."

The film tells the story of H, a pig who survives a mass-culling pit and wants to become human, and Jeongseok, a young man who, after enduring violence, chooses a beast’s life. The two become half-human, half-beast through each other’s blood, but dream of completely opposite lives.

It was director Heo’s idea for one actor to play every character, based on the belief that “all the people in the story are connected as one.” Han performed even the characters who appeared only in passing without speaking. Filming, initially scheduled to take five months over eight shooting days, stretched to three years. “The director pursued perfection, and animation also required many fine adjustments,” he recalled.

Motion capture is a technology that converts an actor’s movements and expressions into digital data and applies them to virtual characters. Actors must perform in a space without costumes, props, backgrounds or even scene partners. “You have to picture the scene in detail in your mind,” Han explained. “It takes much more imagination and concentration than ordinary acting.”

What enabled him to endure the long shoot was his trust in director Heo. Although the director had no experience directing live-action films, he guided the actors with meticulous storyboards and a distinct artistic vision. Before filming, he explained each character’s origins and symbolism. “The director’s experiences and messages were embedded in every character,” Han said. “Rather than trying to reinterpret them, I trusted his intentions and followed his lead.”

A still from the film "The Pig That Came Back Alive from Foot-and-Mouth Disease."

He conveyed the characters’ emotions through even the smallest movements. For the scene in which H, who had been walking on all fours, first stands on two legs, he drew inspiration from a baby learning to walk. It was the moment H first felt hope that he could become human. To portray the unfamiliar sensation of developing joints and toes that pigs do not have, Han even studied anatomical materials.

After becoming half-human, half-beast, Jeongseok gains confidence in his changed body and straightens his shoulders, but still walks cautiously. This suggests that although his appearance has changed, his inner wounds remain. “I made sure the character’s psychology and life experiences came through in the way he walked,” Han explained.

The character he worked hardest on was Jieun, the film’s only female character. In a world ruled by violence and trauma, she brings hope to Jeongseok. Rather than imitating feminine gestures, Han focused on expressing the character’s sincerity. “At first, it was hard to empathize with her. I gradually began to understand her when I considered that people can be beautiful even in a hellish situation. I approached the role with the feeling that I was giving strength to the Jeongseok I was playing.”

He paid close attention to eye movements in the facial expressions. Because of the equipment’s limitations, the body and face had to be filmed separately. “The eyes account for nearly half of a facial performance,” he said. “A person’s expression changes depending not only on the pupils but also on movements between the eyebrows and in the surrounding muscles.”

Motion-capture actor Han Woojin performs a character in "The Pig That Came Back Alive from Foot-and-Mouth Disease" / Courtesy of Hanniverse.

Although his voice was not used in the film, Han performed while speaking every line himself. He did so to help the voice actors naturally carry the characters’ emotions into their performances. “Kim Dohee, the voice actor who played Jieun, watched the finished film, cried and thanked me,” he said. “Her words—that my performance helped her immerse herself in the emotions more easily—stayed with me for a long time.”

The three-year production also changed his perspective on technology. During filming, motion-capture equipment and workflows advanced rapidly, and he saw the potential for AI to be used in video production. That is also why he is currently taking an AI content microdegree program at the Korea Advanced Institute of Science and Technology (KAIST).

Hanniverse’s solution starts with actors’ real performances. AI is used to add the desired visual effects to filmed performances and create the video envisioned by the director. The process is streamlined while the characters’ movements and emotions remain grounded in human performances.

Motion-capture actor Han Woojin (left) and the late director Heo Beomuk / Courtesy of Hanniverse.

“You can now create a variety of videos just by entering prompts, but it is not easy to fully capture a director’s intentions and an actor’s emotions,” Han said. He added, “No matter how much technology advances, actors are best suited to bringing characters to life. I want to advance an approach to AI content production that puts human performances at its center.”

This content was produced with the assistance of AI translation services.