There is only one file type that uses the .XV3 extension:
Lattice XVL Geometry File
File created by Lattice Technology programs, which are used to create Digital Mock Up (DMU) documentation of 3D models; contains a model, including its three-dimensional geometry and appearance; used to save and load 3D design data.
XV3 files are stored in a highly compressed format. Therefore, they are suitable for insertion into CAD documents and other 3D model documentation.
XV3 files can be viewed in the XVL Player, which is a Web browser plug-in.
NOTE: XV3 files are stored using the Lattice Technology XVL (eXtensible Virtual world description Language) format, which is an XML-based format used for compressing and exchanging 3D models.
Updated: January 1, 2010