Mesh Patch Sub-Division for 3D Geometry Reconstruction

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Solution Overview

Problem

Current methods for compressing 3D meshes are not suitable for transmitting the connectivity of points, which is essential for efficient mesh compression, and existing solutions for 3D mesh encoding are inefficient and lack support for attributes of triangle faces.

Innovation Solution

The proposed solution involves post-processing decoded meshes by modifying received triangles per patch to improve mesh geometry. This is achieved through methods such as triangle centroid implementation, edge midpoint implementation, vertex split implementation, and marching cubes, which generate new triangles aligned with the original surface using high-resolution depth maps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If V-PCC projection method is used to compress 3D point clouds, then compression efficiency is improved, but the method cannot transmit connectivity information required for 3D mesh compression

Engineering Contradiction:
Improvecompression efficiencyVSAvoidconnectivity information
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent segments the mesh into multiple patches, encoding each patch independently with its own connectivity information. This allows connectivity to be preserved within each patch while maintaining compression efficiency, resolving the contradiction between compression and connectivity transmission.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds a connectivity dimension to the existing V-PCC projection framework by incorporating face lists and vertex lists that describe mesh topology. This transforms the 2D projection approach into a 3D-aware representation that preserves both compression efficiency and connectivity information.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If RAW patch data is used to encode vertices position, then sparse point clouds can be encoded, but encoding efficiency decreases and triangle face attributes are missing

Engineering Contradiction:
Improvesparse point cloud encoding capabilityVSAvoidencoding efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent merges the advantages of RAW patch encoding (sparse point cloud support) with structured mesh encoding (efficiency and attribute preservation). By combining face lists, vertex lists, and position data in a unified format, it achieves both sparse cloud handling and efficient encoding with complete attribute information.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If mesh is decoded without post-processing, then decoding speed is maintained, but mesh geometry quality is insufficient

Engineering Contradiction:
Improvedecoding speedVSAvoidmesh geometry quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary mesh reconstruction to generate an initial mesh, then applies post-processing operations (subdivision, smoothing, refinement) to improve geometry quality. This two-stage approach maintains decoding speed by preparing data in advance while achieving high geometric precision through targeted post-processing.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS12315081B2Mesh patch sub-division
Publication Date: 2025.05.27 SONY GROUP CORP
  • US12315081B2 patent drawing
  • US12315081B2 patent drawing
  • US12315081B2 patent drawing

AI summary

Ways to post-process a decoded mesh and modify received triangles per patch to improve the mesh geometry are described herein. Since the transmitted geometry contains the high-resolution surface information, the information is able to be applied to the mesh reconstruction operation to generate triangles that are aligned with the original surface. Methods include generating new triangles by splitting the received triangles' edges according to their size, by inserting new vertices at the triangle's centroids, by splitting the vertices, and by performing marching cubes in surfaces defined by the geometry images.