Immortalising Greek dances via 3D recordings
Anastasios Doulamis, professor at the National Technical University of Athens, is creating digital 3D dance recordings to preserve traditional Greek dance cultures threated with extinction. He tells Horizon why this approach is vital for conserving endangered dances – as well as enabling people to better learn and study popular styles.
Greece has thousands of different dances, and each region has its own styles. We dance a lot at summer festivals, weddings and baptisms. Traditional dances are very popular among the young (as well as the old).
At important ceremonies like weddings, people want to express their feelings using traditional Greek dances rather than the dances of another country. I love their rhythm, and the melody and lyrics of the songs which accompany them. Especially the lyrics, which use the power of the Greek language to convey a lot using very few words.
But some dances in remote regions of the country, like Macedonia and Thessaly, are under threat.
Most of us focus on tangible cultural heritage – marvellous buildings, bridges, churches – but we lose the ceremonies. Ceremonies are also part of our human civilisations and declare what people think, how people behave.
According to UNESCO, the intangible part of cultural heritage – dance, oral tradition, cuisine, religious ceremony – is a very big part of our civilisation, of our culture. For me personally it is the most important part.
Culture for me is what we as humans do – not the buildings themselves, but why we build buildings in a particular style, why we wear these clothes, why we dance like this.
The Terpsichore project is named after an ancient (Greek) goddess of dance.
We are capturing endangered Greek dances including Enteka and Trehatos, which are losing popularity because their styles are going out of fashion and they are danced in remote regions.
We are also capturing popular ones like Kalamatianos which is danced in the Peloponnese region at almost all festivals. People used to dance them in regional costumes, but now they simply wear modern clothes.
We record these dances using professional dancers from the department of sports sciences in the Aristotle University of Thessaloniki.
We do not use conventional audiovisual cameras. We create 3D digital recordings using depth sensors which are more accurate because the dancers’ movements can be measured.
Conventional video is two dimensional, it does not give depth. Humans can recognise depth in a video but we cannot use the video to measure (the length of steps and other movements).
The information you get from depth is very important to teach people to dance correctly.
It is also important for (cultural heritage researchers) to be able to compare dances between different countries and regions – to say this dance is related to that dance, to understand the origins of a dance. (This technology means) they can prove the origin – not from written texts or what experts know subjectively – but by objectively measuring the 3D geometric distances of the dance.
Creating 3D digital recordings is becoming easier (and cheaper).
We use two kinds of recording technology: one involves putting marks on a dancer and using specialist Vicon motion capture equipment usually used by professionals (such as sports coaches and physiotherapists). Our recordings were mostly at the University of Thessaloniki.
But we are also showing that you can capture dances using low-cost devices. We hope this means many people can capture dances in 3D, so more dances will be preserved in this format.
We use Microsoft’s Kinect depth sensors, which are less accurate but very cheap – they cost about €100 each. They are used in Xbox gaming consoles to enable people to play tennis hands free, for example.
We use three of these sensors – one in front of the dancer and one on either side – but it can work with just one.
Capturing the geometry of the movements is very tough technologically. There is a lot of movement – it’s not like a building where the geometry is static. If you have multiple dancers you have a lot of occlusions, the geometry is confused and it is difficult for the computer to understand which dancer is which.
So we have performed experiments using one or two dancers up to now. There are some traditional dances with one dancer.
We are uploading as many of these dances as we can onto a digital library. We want to (…) make it accessible to dance teachers and students, cultural experts, and the wider public. This will take a lot of time and additional financial resources.
We think the system will become the main way of recording dances because of the 3D information (it contains). It will be very important for future generations - both cultural heritage experts, and people who want to resurrect these dances again.
I hope 3D motion capturing research will continue and this framework can be used as a milestone for protecting our intangible heritage.