Encoding and progressive transmission of progressive meshes

A computer readable data storage medium having encoded thereon a progressive meshes representation of a multi-dimensional object for computer graphics, the progressive meshes representation comprising:

• a base mesh record for specifying a base mesh representative of the object at a lowest level of detail;
• and
• a plurality of vertex split records for specifying a plurality of vertex split transformations which, when applied successively to the base mesh, yield a succession of meshes representative of the object and having progressively higher levels of detail.

A method of losslessly encoding an arbitrary initial mesh at progressive levels of detail for rendering computer graphics views of a multi-dimensional geometric object, comprising:

• encoding a base mesh record specifying a set of position coordinates and a connectivity of vertices of a base mesh, the position coordinates and connectivity of the vertices defining a plurality of faces having edges between adjacent vertices and corners at the vertices;
• and
• encoding a plurality of vertex split records specifying a split vertex identifier, two side vertex identifiers, and two resulting vertex position coordinates for each of a sequence of vertex split transformations that yield a succession of meshes at progressively increasing levels of detail and exactly reproduce the arbitrary initial mesh when applied in sequence to the succession beginning with the base mesh, each vertex split transformation introducing a new vertex and at least one new face having edges between adjacent vertices and corners at the vertices to a current mesh in the succession to yield a next mesh in the succession.

A system for progressively transmitting a level-of detail representation of an object from a remote site for displaying computer graphics views of the object at a computer, comprising:

• a memory at the remote site for storing a progressive resolution meshes representation of the object comprising a base mesh record and a sequence of vertex split records, the base mesh record defining a base mesh representative of the object at a low level of detail, the sequence of vertex split records defining vertex split transformations that applied successively to the base mesh refine the base mesh into an arbitrary mesh representative of the object at a high level of detail;
• a data transmitter at the remote site for transmitting the base mesh record and a stream of the vertex split records to the computer.