Newly Developed Physics-Based Technology Controlling Soccer Playing Characters, ‘PhysicsFC’

A research team led by Professor Lee Yoon-sang of the Department of Computer Science at Hanyang University drew attention from academia and industry by presenting its research achievements at SIGGRAPH 2025, the world’s premier computer graphics conference, held from August 10 to 14 at the Vancouver Convention Centre, Canada.

The team developed ‘PhysicsFC,’ a technology that enables physics-based simulated soccer player characters to perform various soccer skills—such as dribbling, trapping, and shooting—in real time in reaction to user inputs, thereby going beyond traditional animation-driven gameplay.

PhysicsFC integrates each soccer technique as an independent policy trained through deep reinforcement learning into a Finite State Machine(FSM)-based control architecture. For training, the team utilized motion capture data to build a physics-based motion embedding model, on which each skill policy was learned. These policies can then control character moving patterns and, consequently, movement of the ball. To improve the control, the team introduced a custom-developed method called DEGCL(Data-Embedded Goal-Conditioned Latent Guidance), which naturally handles directional changes such as forward, backward, and lateral movements. Additionally, by applying STI(Skill Transition-Based Initialization), transitions between dribbling, trapping, shooting, and movement became smooth and agile.

Unlike conventional soccer games that rely on pre-rendered animations, PhysicsFC generates all movements of both the character and the ball via physical simulation, providing realistic and immersive gameplay. The approach eliminates awkward animations such as sliding feet or abrupt teleportation, while realistically simulating collisions, falls, and recovery when players interact.

This breakthrough was presented verbally in the Technical Papers session at SIGGRAPH 2025 and was also featured in the Emerging Technologies session, where the team conducted live demonstrations. Industry and academic participants actively engaged in the demonstration, with notable interest from representatives of NBA 2K’s development studio, who engaged in extended discussions with the team.

Professor Lee Yoon-sang commented, "PhysicsFC is more than just a game technology—it has the potential to evolve into a core technology in the emerging field of Physical AI. We expect to foster collaboration with global researchers and companies through this SIGGRAPH presentation."

This research was supported by the National Research Foundation of Korea(NRF), the Korea Creative Content Agency(KOCCA), and the Institute of Information & Communications Technology Planning & Evaluation(IITP). The results were published on July 27 in ACM Transactions on Graphics(TOG), the top-tier journal in the computer graphics field. The paper, titled PhysicsFC: Learning User-Controlled Skills for a Physics-Based Football Player Controller, was co-authored by Hanyang University Master's student Kim Min-su(first author), Master's student Jung Eun-ho(co-author), and Professor Lee Yoon-sang(corresponding author).