Method and apparatus for encoding a mesh model, encoded mesh model, and method and apparatus for decoding a mesh model

An apparatus for encoding points of a 3D mesh model, comprising:

• a computer having one or more processor and memory for storing program instructions, wherein the instructions comprise:
• a determining module configured to determine that the mesh model comprises repeating instances of a connected component, and means for determining for each repeating instance at least one reference point;
• a clustering module configured to cluster the reference points of the repeating instances into one or more clusters;
• and
• an encoder configured to encode the clustered reference points using KD-tree coding, wherein for each cluster a separate KD-tree is generated.

A computer implemented method for decoding points of an encoded 3D mesh model from a bitstream, comprising steps of

• extracting, using a computer, data for an instance of a repeating connected component;
• decoding, using the computer, the instance of the connected component using said extracted data;
• extracting, using the computer, first data defining a number of clusters, second data defining a spatial resolution and third data being positions of a plurality of repetitions of said repeating connected component, the third data being encoded as a KD-tree;
• extracting, using the computer, fourth data defining a portion within the 3D mesh model;
• determining, using the computer, the positions of the plurality of repetitions of said repeating connected component from the third data and the fourth data, wherein the third data are applied to the portion of the 3D mesh model that is defined by the fourth data.