MD2

MD2 is a classic model format introduced by id Software for Quake II. It uses vertex animation (keyframe interpolation) to represent character actions, and was widely adopted in game development from the late 1990s to the early 2000s. It also serves as a standard for many retro game assets.

MD2's technical specifications are limited by its era: mesh vertex counts have upper limits, animation frame counts are fixed, and there is no skeletal system. Compared to modern skeletal animation formats, its expressive capability is limited. It mainly appears in retro game development, engine demos, and legacy asset archiving scenarios.