# Application of Three-Dimensional Vision Technology in Dance
## 3 Application of 3D Vision Technology in the Dance Field
### Dance Teaching  
Traditional dance teaching and rehearsal is relatively single-form, mainly carried out through teachers' explanation and demonstration, as well as students' listening and imitation. This teaching method is less efficient, requiring the teacher to correct each student's posture and movement individually, and is limited by time and space, resulting in its use in dance teaching being limited. Especially in large-scale dance performance rehearsals, the limitations of traditional teaching methods are more significant. Of course, some students will learn by watching dance videos and imitating them, but for most students, it is difficult to mimic the dance movements accurately without professional guidance. 3D vision technology plays a reforming role in dance teaching, dance rehearsal, and teaching image dissemination [62; 63; 64]. Unlike the production of dance performances, movies, and plays, dance teaching is more inclined to utilize 3D vision technology to provide dance learners with an all-around free viewing perspective of the teacher and the actual movement of their parts. In other words, the main observation object is changed from the audience to the dance performers themselves. Therefore, unlike the first two applications, mainly utilizing pseudo-3D vision technology, dance teaching is more likely to utilize higher-level 3D vision technologies such as real holography, AR, and VR that can provide binocular parallax and motion parallax. Among them, binocular parallax mainly facilitates dance learners to understand the spatial relationship and dynamic changes in dance movements and to perceive the teacher's body posture, depth of movement, and spatial layout to understand the artistic expression of dance movements better. Motion parallax further enhances the dance learners' understanding of the dynamics of the teacher's dance movements. By observing the visual changes in the teacher's movements, students can perceive the direction and speed of movement as well as the coherence of the movements. Such visual perception of dynamics is crucial to understanding the fluidity and rhythm of the dance movements, enabling the audience to feel the rhythm and emotional expression of the dance more deeply. The Whole-body Interaction Learning for Dance Education (WhoLoDancE) project, funded by the European Union's Horizon 2020 program, conducted groundbreak-ing research on using digital technology to teach dance and choreography [65, 66]. They utilize motion capture technology and 3D vision technology, such as Mi-crosoft HoloLens Mixed Reality headsets, to capture dances (including ballet, modern, flamenco, and Greek folk dances) and preserved them for future dancers and choreog-raphers to study. They also created various programs to annotate and process the cap-tured images. Captured dances are stored in a movement database where choreoga-phers can select and combine movements and then play new dances using holograms of the dancers. In addition, learners can watch life-size holographic dancers perform the dances they want to learn and dance with them [67]. [PERSON] et al. proposed a VR dance training application with motion capture technology. It is a system that comprehensively analyzes the user's whole body [68]. Dance learners simply put on a motion capture suit, follow the movements of a virtual teacher, and then receive feedback on how to improve their movements. The system's architecture consists of four main components: 3D graphics, motion matching, a motion database, and an optical motion capture system. Among them, the 3D graphics component visualizes the movements of the dance learners and the virtual teacher so that the movement details can be observed from multiple perspectives. In addition, the system applies a mirroring effect to the virtual teacher on the screen. It marks correct and incorrect body parts with different colors so students can learn the dance efficiently and immersively.