mdg winAn MDG file is a 3D model saved in the proprietary Model of Dital Geometry (MDG) CAD format. It contains information about a 3D model in an XML-like syntax. MDG files2,701 Followers, 0 Following, 86 Posts - MDG Space, IITR (@mdgspace) on : Ideas x Reality Log In. Sn Up. mdgspace. Follow. Message 86 posts. 2,700 followers. 0 following.