From Team Fortress Wiki
A bodygroup is a feature of the Source Engine that enables specific sections of a model to be enabled or disabled, allowing for different models to take their place. In Team Fortress 2, bodygroups are used in the models of several items to show or hide specific player or weapon models when needed; for example, most hats manipulate bodygroups to remove the default headgear present on the player model to allow room for the newer hat model.
Bodygroups do not alter hitboxes, they are merely a cosmetic feature.
| List of bodygroup on player models
|| Group name
|| Used by
|| A style for the Bonk Boy, All Hats, except Batter's Helmet.
|| A style for the Bonk Boy, all hats, except Batter's Helmet, Spiral Sallet, and a style of the Backwards Ballcap.
| Shoes and socks
|| Essential Accessories, Flip-Flops, Futankhamun, Ball-Kicking Boots, Bootie Time, Teufort Tooth Kicker and Spooky Shoes.
| Dog tags
|| Sign of the Wolf's School and B-ankh!.
|| All Hats, except Soldier's Stash, Exquisite Rack, Cross-Comm Crash Helmet, and a style of the Battle Bob.
|| The Lumbricus Lid's grenades., Professor's Pineapple, Captain's Cocktails, Ornament Armament, Bonedolier, and Deadliest Duckling.
|| Gentle Manne's Service Medal.
|| Foster's Facade, Apparition's Aspect, HazMat Headcase, Last Breath, Plutonidome, Voodoo-Cursed Pyro Soul, and Winter Wonderland Wrap.
|| Stockbroker's Scarf, Cremator's Conscience, Professor's Pineapple, Burning Bongos, Ornament Armament, Jingle Belt, Bonedolier and Deadliest Duckling.
|| Moonman Backpack, Scrap Pack, Russian Rocketeer, Pyrobotics Pack, Infernal Orchestrina, and Pyrotechnic Tote.
|| Primary taunts.
|| Ali Baba's Wee Booties, Bootlegger, Pickled Paws, Teufort Tooth Kicker, and Voodoo-Cursed Demoman Soul.
|| A Whiff of the Old Brimstone, Professor's Pineapple, Ornament Armament, Battery Bandolier, Bonedolier, and Deadliest Duckling.
|| All melee weapons except Fists, Warrior's Spirit and Eviction Notice.
|| All Hats, except Mining Light, Industrial Festivizer, a style for both the Big Country and Professor's Peculiarity.
| Right Arm
|| Gunslinger and Short Circuit.
|| The Quick-Fix and the Vaccinator's backpacks, Emerald Jarate, Scrap Pack an the Medic Mech-bag.
|| All Hats, except the Trophy Belt.
|| Sydney Sleeper and Silver Bullets.
|| Itsy Bitsy Spyer, Koala Compact, and Deadliest Duckling.
|| Disguise Kit.
August 19, 2008 Patch
(A Heavy Update
- [Undocumented] Added hand bodygroup to the Heavy model.
May 21, 2009 Patch (Sniper vs. Spy Update)
- [Undocumented] Added arrow bodygroup to the Sniper model.
August 13, 2009 Patch (Classless Update)
- [Undocumented] Added hat bodygroups to the Scout, Soldier, Engineer and Sniper models.
- [Undocumented] Added headset bodygroup to the Scout model.
- [Undocumented] Added medal bodygroup to the Soldier model.
July 8, 2010 Patch (Engineer Update)
- [Undocumented] Added right arm bodygroup to the Engineer model.
August 25, 2010 Patch
- [Undocumented] Added grenade bodygroup to the Soldier model.
September 30, 2010 Patch (Mann-Conomy Update)
- [Undocumented] Added bullet bodygroup to the Sniper model.
December 13, 2010 Patch
- [Undocumented] Added head and grenade bodygroups to the Pyro model.
January 24, 2011 Patch
- [Undocumented] Added shoes and socks bodygroup to the Scout model.
April 14, 2011 Patch (Hatless Update)
- [Undocumented] Added hose bodygroup to the Medi Gun.
May 12, 2011 Patch
- [Undocumented] Added dogtag bodygroup to the Scout model.
May 31, 2011 Patch
- [Undocumented] Added leg bodygroup to the Demoman model
June 23, 2011 Patch (Über Update)
- [Undocumented] Added backpack bodygroup to the Medic model.
August 18, 2011 Patch (Manno-Technology Bundle)
- [Undocumented] Fixed Heavy's fist bodygroup not being removed when equipped with certain melee weapons.
March 22, 2012 Patch
- [Undocumented] Added backpack bodygroup to the Pyro.
July 10, 2012 Patch
- Fixed body groups not hiding correctly on ragdolls.
October 26, 2012 Patch (Spectral Halloween Special)
- [Undocumented] Fixed a bug that make certain body groups will fail to activate when required. For example, the Soldier's 'rocket' and Demoman's 'smile' during certain taunts.
November 5, 2012 Patch
- [Undocumented] Fixed the Spooky Shoes not hiding the socks and shoes bodygroup.
- [Undocumented] Fixed the Coffin Kit hiding the backpack bodygroup.
- Some items (e.g. The Pyromancer's Mask and the Splendid Screen) have an alternate style that changes the shape or design on the item. This is accomplished via bodygroups.
- Items that turn off specific bodygroups will not cast a shadow.
- Occasionally, bodygroups will disappear, leaving empty space on the model.
- Occasionally, items will fail to turn off the default bodygroup, leading to the original group clipping into the replacement model.
- Items that replace a removed group will not disappear when the player is backstabbed by Your Eternal Reward.