Volumetric video with long-term patch entity memory

A method comprising:

• obtaining a first atlas packing one or more dynamic patches of a three-dimensional (3D) scene of a sequence of 3D scenes;
• obtaining one or more static patches of the 3D scene, a static patch being associated with an entity, an entity being a part of the 3D scene;
• encoding the first atlas in a data stream;
• on condition that at least one static patch differs from static patches of a previous 3D scene in the sequence of 3D scenes:
• packing one or more static patches in a second atlas and generating metadata indicating, for an entity associated with a static patch, an instruction for a client to:
• create, for the 3D scene, a new entry in a local memory associating the entity with static patches associated with the entity;
• or
• update, for the 3D scene, the entry of the local memory associating the entity with static patches, with static patches associated with the entity;
• or
• delete from the local memory, the entry associating the entity with static patches;
• and
• encoding the second atlas and the metadata in the data stream.

A device comprising a processor configured to:

• obtain, from a data stream, a second atlas packing one or more static patches for a first 3D scene, a static patch being associated with an entity of the 3D scene, an entity being a part of the 3D scene of a sequence of 3D scenes;
• update one or more entries of a local memory with the one or more static patches;
• obtain, from the data stream, a first atlas packing one or more dynamic patches for a second 3D scene of the sequence of 3D scenes;
• obtain entries from a local memory corresponding to static patches associated with entities visible in a viewport to render;
• and
• render the 3D scene by inverse projecting one or more dynamic patches and static patches of obtained entries.

A device comprising a processor configured to:

• obtain a first atlas packing one or more dynamic patches of a 3D scene of a sequence of 3D scenes;
• obtain one or more static patches of the 3D scene, a static patch being associated with an entity, an entity being a part of the 3D scene;
• encode the first atlas in a data stream;
• on condition that at least one static patch differs from the static patches of a previous 3D scene in the sequence of 3D scenes:
• pack static patches in a second atlas and generating metadata indicating, for an entity associated with a static patch, an instruction for a client to:
• create, for the 3D scene, a new entry in a local memory associating the entity with static patches associated with the entity;
• or
• update, for the 3D scene, the entry of the local memory associating the entity with static patches, with static patches associated with the entity;
• or
• delete from the local memory, the entry associating the entity with static patches;
• and
• encode the second atlas and the metadata in the data stream.