# Methodology of 3D Scanning of Intangible Cultural Heritage--The Example of Lazgi Dance
###### Abstract  
Traditional dance is one of the key elements of Intangible Culture Heritage (ICH). Many scientific papers concern analysis of dance sequences, classification and recognition of movements, making ICH data public, creating and visualising 3D models or software solutions for learning folklore dances. These works make it possible to preserve this disappearing art. The aim of this article is to propose a methodology for scanning folklore dances. The methodology was developed on the basis of capturing 3D data via an optical motion capture system with a full body Plug-in Gait model that allows for kinematic and kinetic analysis of motion sequences. An additional element of this research was the development of a hand model with which it is possible to precisely analyse the fingers, which play a significant role in many dances. The present methodology was verified on the basis of the Lazgi dance, included in the UNESCO ICH list. The obtained results of movement biomechanics for the dance sequence and the angles of the fingers indicate that it is universal and can be applied to dances that involve the upper and lower body parts, including hand movements.  
dance scanning; dance capturing methodology; motion capture; Lazgi dance +
Footnote †: [FOOTNOTE:]Footnote †: [FOalso be obtained using various sensors, such as Kinect or Xsens. The 3D data collected is further used for detailed analysis or displaying the moves in various software (e.g., for developing Virtual Reality). This process is also gaining further understanding from ICH.  
Lazgi is an ancient dance created by the inhabitants of the downstream areas of the Amu-Daria River. Its history is closely related to the ancient land of Khorezm, which covers the area south of the Aral Sea. There is an opinion that the ancient meaning of the word \"lazgi\" is trembling, characterised by vigorous body movement and facial expression [4], which very vividly reflects the characteristics of the dance. There are many legends and myths associated with the rise of the dance [4]. The most widespread is the legend of the soul-body connection thanks to the rhythms of Lazgi. After the act of creating the human body, it could not be brought to life because of the soul's reluctance to enter the body. The soul's attitude changed when it heard the melody of the Lazgi dance and began to slowly penetrate the body. Therefore, Lazgi starts with a leisurely introduction, then the dancer takes a position with a hand raised to the sun. Next begins a sequence of movements involving the fingers, wrists, arms, torso and legs. The whole body starts to move by a combination of turns and swings and the rhythm of the dance gradually speeds up [5]. Despite the emergence of numerous wars, natural changes, disasters and social unrest, the Lazgi dance has survived for thousands of years. In 2019 it was inscribed on the Representative List of the Intangible Cultural Heritage of Humanity UNESCO [6].  
The aim of the paper is to develop a universal dance scanning method using the motion capture system with the biomechanical Plug-in Model. The retro-reflecting markers are attached to a special suit according to this model in order to capture the dancer's movements. Additionally, the markers were attached to the dancer's hands in order to capture hand gesticulation. The created hand model is dedicated for capturing a type of dance where the analysis of hand and finger movements is essential. The proposed methodology consists of the following steps: planning the research, motion capture session preparation and implementation and, finally, data post-processing. The analysis of the dance, which verified the proposed methodology, involved indicating the trajectories for the selected parts of the upper and lower body and fingers, as well as changes in angles.