ST-CS-10-339-75
March 2002

SECTION I

HITBOXES AND BONES  (U)

1.  Introduction  (U)

A player consists of four things; bones, a model, a skin and hitboxes.

The model is simply the shape of the player. The skin is overlayed on the model. The model and hitboxes hang off of the bones. When a bone moves (the player runs, or shoots a weapon, or pulls out a grenade, etc) the model and hitboxes hanging off that bones move along with the bone. The skin, simply being overlayed on the model, also moves along accordingly.

A player has twenty hitboxes covering his body. When bullets are fired at a player, the Half-life engine checks to see if the bullets hit any of the hitboxes. If they do, then a hit has been achieved on the player.

The term "player model" is also used to refer to the grouping of bones, model, skin and hitboxes. E.g. "the L337 Krew player model".

The following images show all of the different models.

GIGN	GSG-9	SAS	Seal Team 6
Phoenix Connektion	Arctic Avenger	L337 Krew	Guerilla Warface

The hitboxes for each player model are identical in position, shape and size but the models are not. As such, thin models (L337 Krew) give the appearance of having big hitboxes. This is not the case. It's rather like giving a large coat to a thin person and a fat person. The coat seems bigger on the thin person, and smaller on the fat person, but of course is the same size in both cases.

Note that this was confirmed by dissassembling the model files and examining the hitbox dimensions for each player model.

The reason the images displayed here are not identical in size is a limitation of the software used to obtain these images. The software renders the model so that it is a given height. As such, smaller models are magnified and larger models are shrunk, their bones, skin and hitboxes being resized in like manner.

So, the L337 Krew model, for example, appears taller and his hitboxes appear somewhat differently - but this is simply because he is being shown at about 110 percent size. If all the models could be shown at 100 percent, it would be clear the hitboxes are identical.

The hitboxes are; pelvis, thigh, calf, foot, three spine hitboxes (upper, middle and lower), neck, head, clavicle (shoulder), upperarm, forearm and hand.

The VIP model is identical to the player models. The hostage model however has only nineteen hit boxes and in particular has an extremely large head.

VIP	Hostage

Finally, the chicken model only has nine hitboxes and a particularly large headbox.

Squark!

Different hitboxes take different amounts of damage. Being shot in the chest causes more damage than being shot in the arm. Hitboxes in the same part of the body appear to take the same amount of damage, for example the hand, forearm and upper arm hitboxes all take the same damage. The hitboxes appear to be grouped as arms, legs, chest, pelvis and head. The head takes most damage, then pelvis, chest, legs and finally arms.

Being shot in the head causes about three to four times as much damage as being shot in the chest and as such is often fatal. If a player dies from a shot to the headbox, this is called a headshot. The pelvis appears to take about twice as much damage as a chest hit, but the pelvis is very hard to hit - other hit boxes are in the way.