Machinima
Machinima is a technique in which a recording is made using a game's built-in recording tools, characters and maps in order to produce a video which has a film-like experience above and beyond standard in-game footage.
The Meet the Team videos produced by Valve are good but atypical examples of machinima. They are animated using the game engine but feature specially-written animation sequences and high quality settings which cannot be accessed in-game (without the use of console commands), along with the Original voice actors.
Machinima videos don't always necessarily follow the plot line of a game, if any, or go along with character personalities. Machinima may also include characters, items or effects inaccessible through normal play by modifying or adding items, using movie-making programs, or even using traditional movie-maker tricks. Machinima videos are also not limited to one video game. Some are a collaboration of several video games, even games that do not have a replay or free camera mode.
Creating TF2 machinima
Machinima videos are normally created using the standard demo recording techniques and commands. A list of commands and instructions can be found in the recording demos article. They may also be created using tools in Garry's Mod.
Videos can also be created using the Source Filmmaker, which was released as a part of Pyromania Update. This program can create very high quality videos, similar to the Meet the Team trailers.
