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View, browse and sort the ever-growing list of sessions by day, pass type, topic, and format. With this Session Viewer, you can view GDC 2023 session details and speakers, and share your favorites via social media. You will be able to build your schedule and access it during the show via export or Mobile App, once live. Sessions do fill up and seating is first come, first serve, so arrive early to sessions that you would like to attend.

LIGHTSPEED STUDIOS Developer Summit: HSGI: Cross-Platform Hierarchical Surfel Global Illumination (Presented by LIGHTSPEED STUDIOS)

Jiancong Huang  (Senior Graphics Engineer, LIGHTSPEED STUDIOS, LIGHTSPEED STUDIOS)

Jiaxuan Zhang  (Senior Graphics Engineer, LIGHTSPEED STUDIOS, LIGHTSPEED STUDIOS)

Location: Room 3022, West Hall

Date: Tuesday, March 21

Time: 2:10 pm - 2:40 pm

Pass Type: All Access Pass, Core Pass, Summits Pass, Expo Pass, Audio Pass, Independent Games Summit Pass

Topic: Production & Team Leadership, Programming

Format: Sponsor Developer Summit

Vault Recording: Video

Audience Level: Intermediate


The Global Illumination (GI) system implements the use of surfels as a radiance cache primitive to create and re-create a scene. These surfels are displayed as sparsely distributed voxels which are arranged in a hierarchical way within the graphics memory. This is achieved by voxelizing meshes from triangle rasterization as well as reconstructing surfels from scene depth, scene color and other data from GBuffer. Consequently, this system can be employed on scenes that are completely dynamic and include vertex displacement, procedural mesh and skinning mesh. Moreover, by tracing rays within each frame, the surfels can be updated and, in turn, the GI system can achieve faster convergence.

In this session, we are introducing a novel GI system, which provides a more dynamically indirect lighting approach for full dynamic scenes across platforms.


Attendees will be informed of the most recent details regarding the newly developed GI system. To be precise, the Unreal Engine's Path Tracer can create images of comparable quality. Limited art workflows are not an issue, as sparse voxel based surfels are used to maintain a stable frame rate in real-time.

Intended Audience

This session is intended for developers who aim to enhance the GI system in their games, as well as those who are interested in GI technology across both high-end PC and mobile platforms.