3D models repos has been developed for a long time. Those models can be downloaded for free or at a price charge. Game developers, architects, industrial designers, film production stuff, and interior designers are the main users of the 3D models. These people also sometimes make some cash by selling their models.
Pain/missing point: Almost all repos only have infos about the model itself, not about how to use it: use cases, implementation tips, other context.
Superimpose use cases as additional layer to each 3D model.
Create a website (like Pinterest) for users to create accounts and collect models from different platforms.
Let users share use cases, answer questions about the models, inspirations leading to / resulting from a model, etc.
+ A website (or integrate w/ Pinterest API?) showing 3d & other data layers.
NB: Pinterest is focused on pinner-generated content this year
+ Shared data underlay + schemas for new data layers;
Parallels: Pinterest, Github, StackOverflow
Examples in practice: Unity 3D forum*
Communicate, Organize, Iterate
Game developers, architects, industrial designers, film production stuff, and interior designers are the main users of the 3D models. Find people already trying to solve this problem.
Specifically: Talk to the related Unity forum.