# Methodology of 3D Scanning of Intangible Cultural Heritage--The Example of Lazgi Dance
## 2 Traditional Dance Studies--Literature Overview
### Analysis of Selected Dance Sequences  
The first type of research concerns the analysis of trajectories obtained from motion capture systems, which show the dance rhythm and body kinematics and kinetics parameters. It allows for a better understanding of performance of the dance [28]. In [14] the studies concerning choreographic sequences analysis were performed based on 3D motion capture data. They involved trajectories of hip and foot joints showing the rhythm and periodicity of Greek dance. The average Silhouette value over all frames were also indicated for the particular dancers. In [16] the analysis of hip, knee and ankle joint angles was performed. Male dancers had narrower angles in all the mentioned joints of all the six steps than female dancers during the implementation of the Greek Sytros dance. Additionally, in [15], the dance sequences were analysed in terms of average precision and recall values for different frequency. The identification of the Sytros dance based on rhythm is also presented in [17]. The paper in [39] highlights a scientific approach to capture and \begin{table}
\begin{tabular}{c c} \hline \hline
**County** & **Dance** \\ \hline India & Bharatanatyam [29] \\ Kathak [29] & Kuchipudi [29] \\ Odissi [29] & Kathakali [29] \\ Sattriya [29] & Manipuri [29] \\ Mohiniyattam [29] & Bedhaya Ketawang [30] \\ Indonesia & Musume-doujouji [31] \\ Japan & Didim [32] \\ Korea & Treaders [22] \\ Macedonia & [PERSON]’s choreographic [33] \\ [PERSON] & [PERSON], [PERSON], [PERSON] and Horme, Povazie [34] \\ Thailand & [35; 36; 37; 38] \\ United Arab Emirates & Ayala [39] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._ \begin{table}
\begin{tabular}{c c} \hline \hline
**Data Collection Methods** & **Papers** \\ \hline
3D visualization, 3D poses estimation from a video & [2] \\ Vicon motion capture system & [10; 14; 15; 16; 17; 18; 21; 23; 31] \\ OptiTrack motion capture system & [7; 13; 28; 34] \\ Phasespace4 Impulse X2 motion capture system & [12; 27] \\ Microsoft Kinect & [8; 19; 20; 21; 22; 24; 25; 26; 27; 28; 29; 30; 33] \\ Gyroscopes and accelerometers & [32] \\ Smartphones & [9] \\ Video camera & [11; 29; 33] \\ Labanotation system & [35; 36; 37; 38] \\ IMU sensors & [39] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Technologies used to capture traditional dance data. analyse the biomechanical data of authentic traditional dance motions with the aim to digitally preserve their disappearing inherent rhythmic dying features for future training and coaching purposes. Inertial Measurement Unit (IMU)-based sensors were used to capture three-dimensional movement patterns of a professional traditional Ayala dancer. In [18], the choreography of the same Greek dance was analysed. Optimal key points were distinguished from 3D trajectories that best represented the choreography. These few frames are suitable for modelling an entire choreography, which significantly reduced the amount of information required for processing and storage. It is a particularly important aspect in modelling, analysing and storing this type of data. A Bayesian optimised, bi-directional Long Short-Term Memory (LSTM) network for pose characterisation of a choreography for Greek dance was proposed in [20]. In [21], the identification of dance choreographies based on skeleton data points was used for data obtained from heterogeneous motion capture systems (Vicon motion capture system and Kinect sensor). Finger movements based on gyroscopes and accelerometers attached to the joints for Korean dance were studied in [32]. An example analysis of traditional Hungarian dance analysis considering lower body kinematics, kinetics, biomechanical parameters (Centre of Pressure) and balancing ability through dance movements was described in [28]. The kinematic parameters, such as: Range of Motion (ROM) of knee flexion angle, ROM of hip flexion angle, and ROM of pelvis tilt angle were taken into the consideration. The hip and knee flexion-extension kinetic parameters were calculated for the successive dance steps.