The paper 'Mobile-DDGI: Lightweight Probe-Based Global Illumination via Adaptive Budget Allocation', written by master's graduate Yoo Taek-geun (first author) of the Computer Graphics Laboratory and Professor Lim In-sung (corresponding author) jointly with researchers at Samsung Electronics, was published as a poster at ACM I3D 2026 (30th ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games), one of the top conferences in real-time and interactive 3D graphics. The work also received the Best Poster Award in recognition of its excellence in achieving high-quality real-time global illumination in mobile environments.

DDGI (Dynamic Diffuse Global Illumination) is a probe-based global illumination approximation technique that uses ray tracing to compute indirect diffuse light in real time, and is widely used in real-time rendering including games. Tracing large numbers of rays from each probe every frame is computationally expensive, however, which limits its application in mobile environments with constrained computing resources.

This research proposes Mobile-DDGI, a lightweight probe-based adaptive framework suited to mobile environments. The proposed technique first updates the regions newly brought into view by camera movement. It then concentrates a limited update budget on key probes on the basis of whether they are used in the shading stage, their distance from the camera and their proximity to the centre of the screen. Any remaining budget is used for round-robin sequential updates so that all probes are updated over time. In experiments on the Samsung Exynos 2600 mobile AP, the proposed technique greatly improved the rendering frame rate while maintaining visual quality almost identical to the existing static volume approach, confirming the feasibility of high-quality real-time global illumination in mobile environments.

(Demo link: http://grmanet.sogang.ac.kr/ihm/Images_Movies/I3D2026_Mobile_DDGI_movie_1080P.mp4)

Yoo Taek-geun, the paper's first author and a master's graduate, said: "It is truly meaningful that the research I carried out over two years of my master's course has come back as a valuable result. I am sincerely grateful to Professor Lim In-sung for his passionate guidance and to my laboratory colleagues and seniors who worked alongside me. I hope this research can become a foundation for real-time global illumination technology to be applied to mobile devices in the future."