Why Video Game Breasts Physics Can Go Wrong

How Video Game Breast Physics Work

Basically, in a modern game with 3D graphics, each character has a model. Underneath the textures that cover them like a “skin,” these models are made up of “bones,” which can be manipulated so that the character can move. The number of bones a character can have depends on the game’s graphics engine; certain engines allow for more bones than others.

The number of bones a character has also depends on the overall number of characters rendered at any given moment—the more characters there are, the more taxing it is on whatever hardware is processing the game, so the fewer number of bones each of these characters is likely to have. (Thankfully, real life doesn’t work this way!)


All of these bones are prepped to be animated via a process called “rigging.” Rigging allows developers to determine the extent to which a model can move, and how. Breasts don’t generally move of their own volition, they move in reaction to something else, much like hair and clothes do. If a developer wants breasts to move, then they’ll likely “rig” a character’s chest area.

How the breasts move depends on how many bones are in the bosom area: when breasts both move in unison, it’s likely that the model’s chest has a single joint. If both of the breasts move independent of one another, the chest likely has at least a couple of bones rigged.