It is currently not possible to zoom in, rotate, move or otherwise interact with the object unless multimedia viewer is loaded.
While it is understandable that the 3d file shouldn't automatically fully load because these can be prohibitively large, it would be useful to at least have a click to interact functionality (similar to graphs or maps). If it isn't currently feasible on the article pages, it could at least work in file pages.
It also becomes cumbersome if someone has a lot of small 3d files to have to go back and forth in the 3d viewer, rather than simply interact directly on a page.
The 3d extension adopts a mechanism similar to the Extension:StlHandler which does allow interaction in the file page. Although it probably needs a click to interact functionality to avoid taking time to open file pages which would probably be off-putting to editors.
Side note: The funny thing is that now the multimedia viewer currently does something that the file page cannot, while historically it has been the opposite, e.g. ironically the multimedia viewer can't play videos or audio.