Mesh patch syntax
New syntax elements are used to extend patch types, and the syntax is added to the V3C standard. The new syntax defines patches that encode meshes by projecting connected triangles to a 2D surface, patches that encode triangles or triangle strips without any projection, or patches that are tracked over time and are encoded by projecting connected triangles to a 2D surface. Furthermore, the syntax allows for different ways of coding the mesh-specific information. For instance, the syntax enables three different encoding methods for the vertex position: explicit (directly added to the atlas stream), embedded on video data (occupancy map data), or encoded using an external mesh encoder.
1. A method programmed in a non-transitory memory of a device, the method comprising:
encoding a received mesh using patches;
performing an encoding implementation for vertex position including: directly adding received vertex position information to an atlas stream, and embedding the received vertex position information on received video data, and by using an external mesh coder;
encoding patch connectivity by using one of:
a binary implementation including sending the patch connectivity to an external encoder, or
an explicit implementation by representing triangles by three or four indices and storing the three or four indices in patch data;
encoding patch vertices by using one of:
the binary implementation by sending the patch connectivity to the external encoder,
an occupancy map implementation including a symbol to identify a position of the vertex in the patch, or
an explicit implementation where two coordinates indicate the position in the patch to derive a third coordinate; and
encoding patch mapping coordinates by using one of:
the binary implementation performed by sending the patch connectivity to the external encoder,
an explicit implementation including sending the patch mapping coordinates inside the patch data or
an implicit implementation by assuming the value as the patch position of a corresponding vertex,
which results in encoded vertex position information.
2. The method of claim 1 wherein encoding the mesh using patches comprises projecting connected triangles to a two dimensional surface.
3. The method of claim 1 wherein encoding the mesh using patches comprises using patches that encode triangles or triangle strips without any projection.
4. The method of claim 1 wherein encoding the mesh using patches comprises using patches that are tracked over time and are encoded by projecting connected triangles to a two dimensional surface.
5. The method of claim 1 wherein the video data comprises occupancy map data.
6. The method of claim 1 wherein performing the encoding implementation for vertex position includes delta information for geometry correction.
7. An apparatus comprising:
a non-transitory memory for storing an application, the application for:
encoding a received mesh using patches;
performing an encoding implementation for vertex position including: directly adding received vertex position information to an atlas stream, and embedding the received vertex position information on received video data, and by using an external mesh coder;
encoding patch connectivity by using one of:
a binary implementation including sending the patch connectivity to an external encoder, or
an explicit implementation by representing triangles by three or four indices and storing the three or four indices in patch data;
encoding patch vertices by using one of:
the binary implementation by sending the patch connectivity to the external encoder,
an occupancy map implementation including a symbol to identify a position of the vertex in the patch, or
an explicit implementation where two coordinates indicate the position in the patch to derive a third coordinate; and
encoding patch mapping coordinates by using one of:
the binary implementation performed by sending the patch connectivity to the external encoder,
an explicit implementation including sending the patch mapping coordinates inside the patch data or
an implicit implementation by assuming the value as the patch position of a corresponding vertex,
which results in encoded vertex position information; and
a processor coupled to the memory, the processor configured for processing the application.
8. The apparatus of claim 7 wherein encoding the mesh using patches comprises projecting connected triangles to a two dimensional surface.
9. The apparatus of claim 7 wherein encoding the mesh using patches comprises using patches that encode triangles or triangle strips without any projection.
10. The apparatus of claim 7 wherein encoding the mesh using patches comprises using patches that are tracked over time and are encoded by projecting connected triangles to a two dimensional surface.
11. The apparatus of claim 7 wherein the video data comprises occupancy map data.
12. The apparatus of claim 7 wherein performing the encoding implementation for vertex position includes delta information for geometry correction.
13. A system comprising:
one or more cameras for acquiring three dimensional content; and
an encoder configured for:
encoding a received mesh using patches;
performing an encoding implementation for vertex position including: directly adding received vertex position information to an atlas stream, and embedding the received vertex position information on received video data, and by using an external mesh coder;
encoding patch connectivity by using one of:
a binary implementation including sending the patch connectivity to an external encoder, or
an explicit implementation by representing triangles by three or four indices and storing the three or four indices in patch data;
encoding patch vertices by using one of:
the binary implementation by sending the patch connectivity to the external encoder,
an occupancy map implementation including a symbol to identify a position of the vertex in the patch, or
an explicit implementation where two coordinates indicate the position in the patch to derive a third coordinate; and
encoding patch mapping coordinates by using one of:
the binary implementation performed by sending the patch connectivity to the external encoder,
an explicit implementation including sending the patch mapping coordinates inside the patch data or
an implicit implementation by assuming the value as the patch position of a corresponding vertex,
which results in encoded vertex position information.
14. The system of claim 13 wherein encoding the mesh using patches comprises projecting connected triangles to a two dimensional surface.
15. The system of claim 13 wherein encoding the mesh using patches comprises using patches that encode triangles or triangle strips without any projection.
16. The system of claim 13 wherein encoding the mesh using patches comprises using patches that are tracked over time and are encoded by projecting connected triangles to a two dimensional surface.
17. The system of claim 13 wherein the video data comprises occupancy map data.
18. The system of claim 13 wherein performing the encoding implementation for vertex position includes delta information for geometry correction.