Live2D

Live2D is an animation software program that can be used to generate real-time 2D animations—usually anime-style characters—using layered, continuous parts based on an illustration, without the need of frame-by-frame animation or a 3D model. This enables characters to move using 2.5D movement while maintaining the original illustration.

Live2D characters consist of layered parts saved as a Photoshop file. Layers are separately moved to show the whole animation and expression of the character, such as tilting the head. Parts can be as simple as face, hair, and body, or they can be detailed to eyebrows, eyelashes, and even effects like glinting metal. The number of layers depends on how you wish the Live2D character to move and how three-dimensional you wish the result to appear, with a simplified model having 50 layers and large complex projects reaching 750 layers. There is no limit to how detailed you can be with some even modelling the sides of the teeth for full effect. Unlike a 3D model there isn't a traditional skeleton, but instead the flat layers are warped and rotated. Live2D can be used with real-time motion capture to track movements and perform lip syncing for real-time applications such as vtubing. The downside of the technology is that there is little capability for 360° rotation of complex objects.

Live2D has been used in a wide variety of video games, visual novels, virtual YouTuber channels, and other media. Well-known examples of Live2D media and software include FaceRig, VTube Studio, VTuber Legend, Nekopara, Azur Lane, and virtual YouTubers (as popularized by Hololive, Nijisanji, and VShojo).