In order to change a 3D graphics format, I discovered a new graphical tool: MeshLab is an open source for 3D mesh processing.
This program is developed since 2005 by ISTI and CNR and in order to provide a general purpose tool for manipulating and editing 3D models consequential, including from 3D scans.
It offers a mesh filter cleaning (removal of unreferenced eg vertex), re-meshing tools (simplification, subdivision surface reconstruction ...) and noise suppression functions (softening, etc ... ).
MeshLab is available in different platforms, including Windows, Linux and Mac OS X. It supports the following storage formats: PLY, STL, OFF, 3DS, VRML 2.0, X3D and COLLADA.
MeshLab is used in many areas of research and academia, such as microbiology, cultural heritage management, surface reconstruction and three-dimensional printing.