Add MPEG_node_avatar

[haudiobe]

Signaling an avatar at a node level is achieved by the definition of the MPEG_node_avatar extension. Depending on the input components and the offline model, the proper avatar reconstruction and animation needs to be instantiated to generate the final dynamic/animated 3D mesh of the avatar. When considering describing a user’s avatar in scene description, the following requirements are derived:

The avatar may be reconstructed/animated from a wide range of Avatar representations,
The reconstructed/animated avatar representation abides by the supported primitives in scene description,
It is possible to associate interactivity triggers with different parts/segments of the user avatar (e.g. hand or finger) using the node interactivity triggers.
To address these requirements, the avatar reconstruction/animation is assumed to be independent of the avatar rendering. This design aligns with the principles and architecture of this specification. Irrespective of the chosen avatar representation format, the Presentation Engine is then only required to render the reconstructed avatar in one of the supported 3D formats, such as a dynamic mesh.

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1 out of 4 committers have signed the CLA.

✅ ibouazizi
❌ nlsdvl
❌ haudiobe
❌ lelievres
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