['< sod > [ [ virtual reality ] ] and [ [ augmented reality ] ] services allow users to interact effectively with digital content in real - time. this can be useful for training simulations, visual perception tests, or performing performing a virtual walk - throughs in a 3d environment. motion capture technology is frequently also used in [ [ digital puppetry ] ] systems to drive computer generated characters in real - time. < eod > < sod > [ [ virtual reality ] ] and [ [ that augmented reality ] ] providers, such as [ [ usens ] ] and [ [ gestigon ] ], allow users to interact with digital content in almost real time by capturing hand held motions. this can be useful for training simulations, visual perception tests, or performing a virtual walk - throughs in a standard 3d environment. motion capture technology is frequently used in [ [ digital puppetry ] ] platform systems to drive computer generated characters in real - high time. < eod >']