A T-pose, sometimes known as a bind pose or reference pose, is the default unanimated state of a model in 3D graphics. This pose is often with all of a model's various parts straightened out or flattened for ease of animation. For most characters, this results in a pose where the legs are straight and the arms are pointing sideways in a T-shape.
While a game is in development, character models are created and later textured; in this case, the bind pose acts as the best way to allow the development team to apply textures to character models, as it allows viewers to see most parts of the model's body with no obstructions. As expected, the Super Smash Bros. series is no exception to this "rule" of development, and players can potentially view the original bind poses using external programs, such as BRRES Viewer.
While the vast majority of characters in Smash use standard T-poses, certain characters have variants due to their body characteristics. Yoshi and R.O.B., for instance, have their arms extended in front of their bodies, while Ganondorf's armour in Melee forces him to take on an "A-pose" instead of a T-pose. In the T-Pose glitch for Smash 4, Link is the only character that has a regular battle pose rather than a T for unknown reasons. However, internally he is no exception, and is in the standard T.
Characters that use model effects for facial expressions (such as Sonic or Kirby) can have their facial expressions look unusual when forced into their bind pose. Sonic's eyes, for instance, will always appear closed, while Kirby's mouth will be forced into his standard "o" shape.
Bind poses are generally only intended for game development and, in theory, they should never be seen in the actual gameplay of a final product. In Super Smash Bros. Brawl, however, some attacks will cause bind poses to appear for a single frame, such as Olimar's Pikmin Chain and Ganondorf's Beast Ganon; seeing these bind poses, however, requires almost perfect timing with the pause button, as well as external help by slowing the game's pace down considerably.
Hacks and glitches are the most common method to seeing bind poses appear in gameplay, as they act as a failsafes for animations that do not exist, thus helping to prevent game crashes. Moveset swap hacks, for instance, are particularly notorious for featuring numerous bind poses, as bind poses are used when the two involved characters' special moves have an unequal number of frames or if the two animations have different names. Furthermore, hacking ordinarily non-playable characters into brawls, such as Giga Bowser, will cause their losing poses to be the bind pose on the results screen, due to a lack of "applause" animations. In Smash 4, a glitch could also force bind poses to appear on the results screen if the Home button was pressed 1 frame before the beginning of the victory pose, as it could prevent the game from properly loading such poses; this glitch was later patched out in version 1.1.0.
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