Dynamic mesh coding with simplified topology

Patent metadata

Field	Value
Publication number	US-12536709-B2
Application number	US-202218724601-A
Country	US
Kind code	B2
Filing date	Dec 28, 2022
Priority date	Dec 29, 2021
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A computer-implemented method for decoding a coded mesh bitstream of a dynamic mesh representing three-dimensional content includes that: geometry information of the dynamic mesh is reconstructed from a geometry component bitstream in the coded mesh bitstream, the reconstructed geometry information includes data specifying vertices of the dynamic mesh; connectivity information of the dynamic mesh is reconstructed from a connectivity component bitstream in the coded mesh bitstream, the reconstructed connectivity information includes data specifying faces of the dynamic mesh; the reconstructed connectivity information is refined based on the reconstructed geometry information to generate refined connectivity information by at least dividing a face specified by the reconstructed connectivity information into two faces based on a vertex specified in the reconstructed geometry information; the dynamic mesh is reconstructed based on the reconstructed geometry information and the refined connectivity information; and the reconstructed dynamic mesh is caused to be rendered for display.

First claim

The invention claimed is:

1 . A computer-implemented method for decoding a coded mesh bitstream of a dynamic mesh representing three-dimensional (3D) content, the method comprising:
reconstructing geometry information of the dynamic mesh from a geometry component bitstream in the coded mesh bitstream, the reconstructed geometry information comprising data specifying a plurality of vertices of the dynamic mesh; reconstructing connectivity information of the dynamic mesh from a connectivity component bitstream in the coded mesh bitstream, the reconstructed connectivity information comprising data specifying a plurality of faces of the dynamic mesh; refining the reconstructed connectivity information based on the reconstructed geometry information to generate refined connectivity information by at least dividing a face out of the plurality of faces specified by the reconstructed connectivity information into two faces based on a vertex of the plurality of vertices specified in the reconstructed geometry information; reconstructing the dynamic mesh based on the reconstructed geometry information and the refined connectivity information; and causing the reconstructed dynamic mesh to be rendered for display.

2 . The computer-implemented method of claim 1 , wherein refining the reconstructed connectivity information based on the reconstructed geometry information comprises:
identifying a vertex of the plurality of vertices that is located inside a face of the plurality of faces; determining a projected vertex of the vertex on an edge of the face; and dividing the face into two refined faces, each refined face has the projected vertex as one vertex.

3 . The computer-implemented method of claim 2 , wherein each of the two refined faces have a same orientation as the face.

4 . The computer-implemented method of claim 2 , wherein determining the projected vertex of the vertex comprises:
determining a nearest edge for the vertex among edges of the face, wherein a distance between the vertex to the nearest edge is smaller than another distance between the vertex to another edge of the edges of the face; and determining the projected vertex as an intersection of a line with the nearest edge, the line passing through the vertex and an opposite vertex of the face that does not belong to the nearest edge.

5 . The computer-implemented method of claim 1 , wherein refining the reconstructed connectivity information based on the reconstructed geometry information comprises:
identifying two or more vertices of the plurality of vertices that are located inside a face of the plurality of faces; selecting, among the two or more vertices, a vertex for processing based on a distance between each of the two or more vertices and a corresponding nearest edge; determining a projected vertex of the selected vertex on an edge of the face; and dividing the face into two refined faces, each refined face has the projected vertex as one vertex.

6 . The computer-implemented method of claim 5 , wherein selecting the vertex for processing among the two or more vertices comprises:
determining, for each vertex of the two or more vertices, a nearest edge among edges of the face, wherein a distance between the vertex to the nearest edge is smaller than another distance between the vertex to another edge of the edges of the face; and selecting the vertex for processing as a vertex among the two or more vertices that has a largest distance to the corresponding nearest edge.

7 . The computer-implemented method of claim 1 , wherein reconstructing the geometry information of the dynamic mesh from the geometry component bitstream comprises decoding the geometry component bitstream by a video decoder.

8 . A non-transitory computer-readable medium having program code that is stored thereon, the program code executable by one or more processors for performing operations comprising:
reconstructing geometry information of a dynamic mesh from a geometry component bitstream in a coded mesh bitstream of the dynamic mesh, the reconstructed geometry information comprising data specifying a plurality of vertices of the dynamic mesh; reconstructing connectivity information of the dynamic mesh from a connectivity component bitstream in the coded mesh bitstream, the reconstructed connectivity information comprising data specifying a plurality of faces of the dynamic mesh; refining the reconstructed connectivity information based on the reconstructed geometry information to generate refined connectivity information by at least dividing a face out of the plurality of faces specified by the reconstructed connectivity information into two faces based on a vertex of the plurality of vertices specified in the reconstructed geometry information; reconstructing the dynamic mesh based on the reconstructed geometry information and the refined connectivity information; and causing the reconstructed dynamic mesh to be rendered for display.

9 . The non-transitory computer-readable medium of claim 8 , wherein refining the reconstructed connectivity information based on the reconstructed geometry information comprises:
identifying a vertex of the plurality of vertices that is located inside a face of the plurality of faces; determining a projected vertex of the vertex on an edge of the face; and dividing the face into two refined faces, each refined face has the projected vertex as one vertex.

10 . The non-transitory computer-readable medium of claim 9 , wherein each of the two refined faces have a same orientation as the face.

11 . The non-transitory computer-readable medium of claim 9 , wherein determining the projected vertex of the vertex comprises:
determining a nearest edge for the vertex among edges of the face, wherein a distance between the vertex to the nearest edge is smaller than another distance between the vertex to another edge of the edges of the face; and determining the projected vertex as an intersection of a line with the nearest edge, the line passing through the vertex and an opposite vertex of the face that does not belong to the nearest edge.

12 . The non-transitory computer-readable medium of claim 8 , wherein refining the reconstructed connectivity information based on the reconstructed geometry information comprises:
identifying two or more vertices of the plurality of vertices that are located inside a face of the plurality of faces; selecting, among the two or more vertices, a vertex for processing based on a distance between each of the two or more vertices and a corresponding nearest edge; determining a projected vertex of the selected vertex on an edge of the face; and dividing the face into two refined faces, each refined face has the projected vertex as one vertex.

13 . The non-transitory computer-readable medium of claim 12 , wherein selecting the vertex for processing among the two or more vertices comprises:
determining, for each vertex of the two or more vertices, a nearest edge among edges of the face, wherein a distance between the vertex to the nearest edge is smaller than another distance between the vertex to another edge of the edges of the face; and selecting the vertex for processing as a vertex among the two or more vertices that has a largest distance to the corresponding nearest edge.

14 . The non-transitory computer-readable medium of claim 8 , wherein reconstructing the geometry information of the dynamic mesh from the geometry component bitstream comprises decoding the geometry component bitstream by a video decoder.

15 . A system comprising:
a processor; and a non-tran

Assignees

• Guangdong Oppo Mobile Telecommunications Corp Ltd

Inventors

• Zakharchenko Vladyslav
• Yu Yue
• Yu Haoping

Classifications

• G06T2210/56

  Particle system, point based geometry or rendering · CPC title

• G06T2210/36

  Level of detail · CPC title

• G06T17/205

  Re-meshing · CPC title

• G06T17/20

  Finite element generation, e.g. wire-frame surface description, {tesselation} · CPC title

• G06T9/20

  Contour coding, e.g. using detection of edges · CPC title