[Animats]

What information does it send remotely? Is it all the 3D info for every object?

For most games, no. For big 3D virtual worlds, yes. This is a big difference between games and "metaverse" systems. Most games use a big bulk asset download, rather than dynamically loading assets is needed. What to load next at what level of detail given the current location of the camera has to be well handled to provide a good user experience. It's similar to the problems of displaying a partially loaded web page, only in 3D in real time with far more content.