Summary of S4-260145: Pseudo-CR on Dancer Example for Dynamic 3DGS Content Use Case

Document Overview

This contribution proposes adding a detailed dancer scenario example to TR 26.958 as an illustrative use case for Dynamic 3D Gaussian Splatting (3DGS) content. The document is submitted by Pengcheng Laboratory and China Mobile Com. Corporation for SA4 Meeting #135.

Main Technical Contributions

Dynamic 3DGS Content Use Case Enhancement (Section 5.4)

General Description

The contribution expands the existing Dynamic 3DGS content use case description with the following key characteristics:

• Content Type: Time-varying 3DGS content depicting dynamic subjects or scenes (performers, dancers, singers, exhibition moments, bands, sport actions)
• Delivery Model: Pre-recorded dynamic 3DGS sequences via on-demand streaming or file download
• Rendering: Real-time rendering on UE with potential network assistance (partial delivery or network-assisted rendering)
• User Interaction: Local viewpoint adjustment within constrained navigation volume while scene changes dynamically over time
• Rendering Primitive: 3D Gaussian splats (analogous to volumetric video but using splats instead of textured meshes or voxels)
• Alignment: Corresponds to 3GPP TR 26.928 Use Case 3: Streaming of Immersive 6DoF (non-live/on-demand variant)

Dancer Scenario Example

The contribution introduces a comprehensive dancer performance example with the following technical specifications:

Scene Representation:
- Dynamic 3DGS sequence representing dance performance captured over short temporal interval
- Time-indexed sequence of 3D Gaussian splats encoding:
- Continuous body motion
- Pose transitions
- Expressive gestures of one or multiple dancers
- Relevant stage elements

Playback Characteristics:
- UE receives successive temporal segments
- Real-time rendering preserving temporal continuity and rhythm
- Motion evolution according to encoded timeline
- Spatial structure coherence maintained across frames

User Interaction Model:
- Viewpoint Adjustment: Interactive control within constrained navigation volume derived from original capture setup
- Permitted Operations: Limited rotation, translation, or zoom
- Benefits: Enhanced perception of choreography, spatial relationships between performers, and fine-grained motion details
- Constraints: Visual consistency ensured while avoiding out-of-distribution views

Navigation Paradigm:
- Temporal Navigation: Driven by playback timeline (time-continuous)
- Spatial Navigation: User-controlled within permitted range
- Combined Experience: Time-continuous playback with interactive viewpoint exploration

Scope Limitations

The contribution explicitly defines the following scope boundaries:

In Scope:
- Delivery of pre-recorded sequences
- Decoding of dynamic 3DGS content
- Real-time rendering on mobile devices
- On-demand streaming or file download

Out of Scope:
- Live dynamic 3DGS capturing and delivery (may be considered later depending on feasibility)
- Capture processes
- Real-time communication

Technical Focus

The use case specifically targets:
- Human-centric 3D Gaussian scene reconstruction
- Capturing intricate details of human motion and dynamic appearance changes within confined volume
- Reference implementation for evaluating 3DGS rendering performance on mobile devices
- High-fidelity character rendering

Visual Material

The contribution includes Figure 5.x illustrating the dancer scenario, showing time-indexed dynamic 3DGS sequence playback with temporal progression preservation and user viewpoint adjustment capabilities within the allowed navigation volume.