VUE

VUE is a 3D scenery / world-building program which uses its own proprietary format for saving scene files. This does not appear to be documented online, nor is it widely supported for import/export by programs other than Vue itself. (When the question was asked on a forum, "Is there any software that can import a vue scene?", the glib first answer was "No.", followed by somebody answering "Vue!".)

Apparently, .vue files are scenes, and .vob files are objects.

Sample files
There are several sites claiming to offer "free VUE downloads", but they all seem to have registration walls, and some also seem to push hard to offer you paid downloads even if you check "free" in the selection options. If you're desperate enough to find sample files to analyze that you're willing to go through that, here are a couple of them:
 * Turbosquid
 * Cgtrader
 * DeviantArt

Links

 * Vue program info