Summary of S4-260140: Sport Example for Dynamic 3DGS Content Use Case

Document Overview

This change request proposes adding a sports scenario example to TR 26.958 to illustrate the Dynamic 3DGS (3D Gaussian Splatting) content use case. The contribution is from Pengcheng Laboratory and China Mobile, targeting the FS_3DGS_MED study item.

Main Technical Contributions

Use Case Enhancement - Dynamic 3DGS Content (Section 5.4)

Core Use Case Description (Section 5.4.1)

The document enhances the existing Dynamic 3DGS content use case description with the following key characteristics:

• Content Type: Time-varying 3DGS content depicting dynamic subjects/scenes (performers, dancers, singers, exhibitions, bands, sport actions)
• Rendering Approach: Real-time rendering of 3DGS content sequences on the UE
• Network Support: Delivery and rendering may be assisted through:
• Partial delivery mechanisms
• Network-assisted rendering
• User Interaction: Viewpoint adjustment within a constrained navigation volume while the scene changes dynamically
• Rendering Primitive: 3D Gaussian splats (as opposed to textured meshes or voxels used in volumetric video)

Scope Definition

• Primary Focus: Delivery, decoding, and real-time rendering of pre-recorded dynamic 3DGS sequences
• On-demand streaming
• File download scenarios
• Future Consideration: Live dynamic 3DGS capturing and delivery (feasibility-dependent, later stage)
• Alignment: Corresponds to TR 26.928 Use Case 3: Streaming of Immersive 6DoF (non-live/on-demand variant)

Sports Action Example

Scenario Description

The CR introduces a basketball game segment as an illustrative example (Figure 5.1):

• Content Representation: Dynamic scene encoding both:
• Evolving motion of players
• Surrounding environment
• Represented as time-indexed sequence of 3D Gaussian splats

Playback Characteristics

• Temporal Handling:
• UE receives successive temporal segments

• Continuous rendering to preserve temporal progression

• Spatial Navigation:

• User-controlled viewpoint adjustments including:
  • Limited rotation
  • Translation
  • Zoom
• Enables observation from different perspectives without altering temporal sequence

Navigation Constraints

• Temporal Navigation: Driven by playback timeline
• Spatial Navigation:
• User-controlled within permitted range
• Constrained to allowed-view volume derived from original capture configuration
• Ensures visual coherence and avoids out-of-distribution views
• Combined Interaction: Time-continuous playback with interactive viewpoint exploration

Technical Significance

This contribution provides a concrete, large-scale example for Dynamic 3DGS content use cases, specifically addressing:

• Wide-area environments with complex background dynamics
• Fast-moving subjects (athletes)
• Traffic analysis requirements for extensive 3DGS environments
• Requirement derivation for the FS_3DGS_MED study

The sports scenario serves as a representative example for understanding delivery, rendering, and interaction requirements for dynamic 3DGS content in challenging real-world conditions.