The Player Experience
In both Film and Games 3D can be used to achieve otherwise impossible effects, in gaming there are few alternatives, the game will usually use either 2D or 3D art and be composed entirely of these works, however film has the option of mixing 3D with real life scenarios or making entire films in 3D.
Motion Capture (or Mocap for short) is a technique which allows for 3D animation to be very real to life as it is based off of recordings of Mocap actors who wear specialised suits. The Mocap actors will be recorded acting out a scene and later the recording will be used as a reference from which 3D animators can create highly realistic body and face movements. This can be seen in both film and games, however it is used far more often in Films as it is far more effective in a predetermined scene (which a film is entirely composed of) rather than a dynamic scene as is seen in many games (though Mocap will be more prevalent in cutscenes). In film Mocap recordings will likely be done early in production alongside other acting and then closer to the end of production the recording will be finalised in 3D. In games these recordings and animations will likely be closer to the end of production as many games will focus on gameplay first and cutscenes after a good basis of gameplay has been developed.
3D can also be used in Film as a way to create scenes that would be impossible to act out, such as the destruction of a city, 3D can be used to replace real world environments so that these scenes can be created. In 3D games this will not be as big of an issue as the entire world can be manipulated, however for these effects to be possible in film 3D must be employed to allow for feats that would otherwise be impossible or too expensive to record. In 3D games 3D environments will be there from the start, perhaps becoming more developed as production moves along. In film 3D environments must be researched and then be modelled and afterwards details and manipulations or effects such as explosions must be added afterwards.