# US 12,602,837 B2 · On sub-division of mesh sequences > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,602,837 B2 - Document ID: US12602837B2 - Status: Granted - Kind: B2 - Application number: 18/672,798 - Filed: 2024-05-23 - Published: 2024-11-28 - Granted: 2026-04-14 - Earliest claimed: 2023-05-24 - Assignees: Tencent America LLC - Applicants: Tencent America LLC - Inventors: Wen Gao; Jun Tian; Xiaozhong Xu; Shan Liu - Web page: https://patentgrep.com/patent/US12602837B2 ## CPC - G06T 9/001: {Model-based coding, e.g. wire frame} - G06T 9/004: {Predictors, e.g. intraframe, interframe coding} - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A method and apparatus comprising computer code configured to cause a processor or processors to obtain, from a bitstream, a mesh representing an encoded volumetric data of at least one three-dimensional (3D) visual content, and decode the encoded volumetric data based on displacement vectors of vertices of the mesh, and the displacement vectors are based on a square root of three subdivision in which faces of the mesh are iteratively subdivided in a manner in which a number of subdivided faces resulting from subdividing the mesh in an iteration is less than four times a number of faces from before subdividing the mesh in the iteration. ## Claims ### Claim 1 A method for video decoding, the method performed by at least one processor and comprising: obtaining, from a bitstream, a mesh representing an encoded volumetric data of at least one three-dimensional (3D) visual content; and decoding the encoded volumetric data based on displacement vectors of vertices of the mesh, wherein the displacement vectors are based on a square root of three subdivision in which faces of the mesh are iteratively subdivided in a manner in which a number of subdivided faces resulting from subdividing the mesh in an iteration is less than four times a number of faces from before subdividing the mesh in the iteration. ### Claim 2 (depends on 1) The method for video decoding according to claim 1, wherein the square root of three subdivision comprises, in the iteration: inserting one of a plurality of inserted vertices into ones of the faces from before subdividing the mesh in the iteration, and interconnecting the plurality of inserted vertices thereby forming the number of subdivided faces of the mesh. ### Claim 3 (depends on 2) The method for video decoding according to claim 2, wherein inserting one of the plurality of inserted vertices into ones of the faces from before subdividing the mesh in the iteration comprises inserting only one of the plurality of inserted vertices per the faces from before subdividing the mesh in the iteration. ### Claim 4 (depends on 3) The method for video decoding according to claim 3, wherein at least one of the inserted vertices, inserted into one of the faces from before subdividing the mesh, is based on a linear combination of coordinates of vertices of the one of the faces. ### Claim 5 (depends on 4) The method for video decoding according to claim 4, wherein the linear combination comprises each of the coordinates of the vertices of the ones of the faces scaled by respective non-negative real coefficients. ### Claim 6 (depends on 5) The method for video decoding according to claim 5, wherein the respective non-negative real coefficients are each set to ⅓. ### Claim 7 (depends on 2) The method for video decoding according to claim 2, wherein the square root of three subdivision comprises subdividing boundary edges of the mesh differently than interior edges of the mesh such that at least two new inserted vertices are added in the iteration to at least one of the boundary edges. ### Claim 8 An apparatus for video decoding, the apparatus comprising: at least one memory configured to store computer program code; at least one processor configured to access the computer program code and operate as instructed by the computer program code, the computer program code including: obtaining code configured to cause the at least one processor to obtain, from a bitstream, a mesh representing an encoded volumetric data of at least one three-dimensional (3D) visual content; and decoding code configured to cause the at least one processor to decode the encoded volumetric data based on displacement vectors of vertices of the mesh, wherein the displacement vectors are based on a square root of three subdivision in which faces of the mesh are iteratively subdivided in a manner in which a number of subdivided faces resulting from subdividing the mesh in an iteration is less than four times a number of faces from before subdividing the mesh in the iteration. ### Claim 9 (depends on 8) The apparatus for video decoding according to claim 8, wherein the square root of three subdivision comprises, in the iteration: inserting one of a plurality of inserted vertices into ones of the faces from before subdividing the mesh in the iteration, and interconnecting the plurality of inserted vertices thereby forming the number of subdivided faces of the mesh. ### Claim 10 (depends on 9) The apparatus for video decoding according to claim 9, wherein inserting one of the plurality of inserted vertices into ones of the faces from before subdividing the mesh in the iteration comprises inserting only one of the plurality of inserted vertices per the faces from before subdividing the mesh in the iteration. ### Claim 11 (depends on 10) The apparatus for video decoding according to claim 10, wherein at least one of the inserted vertices, inserted into one of the faces from before subdividing the mesh, is based on a linear combination of coordinates of vertices of the one of the faces. ### Claim 12 (depends on 11) The apparatus for video decoding according to claim 11, wherein the linear combination comprises each of the coordinates of the vertices of the ones of the faces scaled by respective non-negative real coefficients. ### Claim 13 (depends on 12) The apparatus for video decoding according to claim 12, wherein the respective non-negative real coefficients are each set to ⅓. ### Claim 14 (depends on 8) The apparatus for video decoding according to claim 8, wherein the square root of three subdivision comprises subdividing boundary edges of the mesh differently than interior edges of the mesh such that at least two new inserted vertices are added in the iteration to at least one of the boundary edges. ### Claim 15 A non-transitory computer readable medium storing a program causing a computer to: obtain, from a bitstream, a mesh representing an encoded volumetric data of at least one three-dimensional (3D) visual content; and decode the encoded volumetric data based on displacement vectors of vertices of the mesh, wherein the displacement vectors are based on a square root of three subdivision in which faces of the mesh are iteratively subdivided in a manner in which a number of subdivided faces resulting from subdividing the mesh in an iteration is less than four times a number of faces from before subdividing the mesh in the iteration. ### Claim 16 (depends on 15) The non-transitory computer readable medium according to claim 15, wherein the square root of three subdivision comprises, in the iteration: inserting one of a plurality of inserted vertices into ones of the faces from before subdividing the mesh in the iteration, and interconnecting the plurality of inserted vertices thereby forming the number of subdivided faces of the mesh. ### Claim 17 (depends on 16) The non-transitory computer readable medium according to claim 16, wherein inserting one of the plurality of inserted vertices into ones of the faces from before subdividing the mesh in the iteration comprises inserting only one of the plurality of inserted vertices per the faces from before subdividing the mesh in the iteration. ### Claim 18 (depends on 17) The non-transitory computer readable medium according to claim 17, wherein at least one of the inserted vertices, inserted into one of the faces from before subdividing the mesh, is based on a linear combination of coordinates of vertices of the one of the faces. ### Claim 19 (depends on 18) The non-transitory computer readable medium according to claim 18, wherein the linear combination comprises each of the coordinates of the vertices of the ones of the faces scaled by respective non-negative real coefficients, and wherein the respective non-negative real coefficients are each set to ⅓. ### Claim 20 (depends on 15) The non-transitory computer readable medium according to claim 15, wherein the square root of three subdivision comprises subdividing boundary edges of the mesh differently than interior edges of the mesh such that at least two new inserted vertices are added in the iteration to at least one of the boundary edges.