How to create 3D augmented reality, in real time — without a computer / by Karen Frances Eng

Light artist Christine Marie has reinvented an early projection technology to create live performances and installations with giant 3D shadows.

Imagine a dark space, dancers on stage, vivid colored lights behind them as they move. Their shadows grow, loom far above your head — then seem to reach and lunge towards you. It’s a feat of visual trickery—you could even call it augmented reality. Yet there are no computers here, just bright lights and colored glass. Light artist and TED Fellow Christine Marie has put a 21st-century spin on centuries-old technology she calls the shadow stereoscope, creating live performances that give audiences an immersive 3D experience—with no electronics in the way.

Next month, Sundance Film Festival will feature (antiquated) Augmented Reality—Christine Marie’s pioneering work featuring theatrical scenography, choreography and her pre-cinematic stereoscopic imaging technique—in its New Frontier program showcasing emerging storytelling media. Here, we get a sneak peek of the piece, and ask her to tell us more.

Photos courtesy of Christine Marie. Photo credits: Vanessa Crocini, Christine Marie and Bryndis Hafthorsdottir. Dancers: Taylor Unwin, Gigi Todisco, Sandra Ruiz.

Photos courtesy of Christine Marie. Photo credits: Vanessa Crocini, Christine Marie and Bryndis Hafthorsdottir. Dancers: Taylor Unwin, Gigi Todisco, Sandra Ruiz.

Can you explain how 3D works, and how you use it?

“Anaglyph” is name for the 3D effect made possible by red-and-blue filters. Here’s how it works: When two lights converge to the same point on a surface, and each light is filtered, turning one red and the other cyan, the bare eye sees a red and slightly offset cyan shadow. When the viewer puts on 3D glasses — covering the opposite eye with cyan and the other with red — they experience the perception of a three-dimensional image.

Any shape or body placed in front of the lights will produce a black dimensional shadow at varying distances in cubic space. 3D shadows are also referred to as “shadowgraphs” and “shadowgrams.” I feel that the best name for the instrument I’ve created is “shadow stereoscope,” as it’s a stereo imaging device for casting 3D shadows.

In what way is this technology “antiquated”? What’s its history?

The first attempts to create a 3D effect with colored glass were recorded in the 1700s. Then, in 1838, Sir Charles Wheatstone used the word “stereoscopic” to refer to the perception of depth in a pair of viewed images. The first anaglyphic projections of stereographs onto a screen was done by Charles d’Almeida in 1858, but my particular apparatus is most similar to a method recorded by inventor Laurens Hammond in 1924, using red and green light and rear projected shadows.

What did people create with stereoscopic technology?

There’s very little recorded with regards to the content of the stereoscopic shadow shows of the past. Eric Kurland, the founder of 3-D Space in Los Angeles, has a pair of anaglyph glasses once used in the Ziegfield Follies in the 1920s for a vaudeville act. The technique was licensed to them by Hammond. Most likely, by the time this technology was perfected, film had become so popular and inexpensive to see that there was little interest in watching shadow plays. So we don’t know much.

Christine Marie in red/cyan anaglyph glasses.

Christine Marie in red/cyan anaglyph glasses.

What have you done to update and innovate this technology?

My invention uses brighter lamps and more power, thus bigger, brighter chromatic shadows that have an extreme z-axis orientation—the axis of depth. I seek shapes and objects that pierce, permeate and overcome the cubic space by casting lines of light to surround the viewer and immerse them in a tunnel, spinning a cube that puts the viewer at its center, immersing them in ever-shifting squares. The experience I want the audience to have is one of complete immersion, beauty and free association that awakens the unconscious mind.

Few contemporary artists use the technique. The ones who do use it to cast smaller shadows for photographs, to create vaudevillian throwbacks or to use shadows for effect — like a shark prop popping out. I’m the only artist creating non-digital anaglyph 3D shadows at a large scale — up to 40 feet — for live performance and interactive installations.

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How do you train performers to work within this very unique format?

For (antiquated) Augmented Reality, I work exclusively with dancers and a choreographer. I love the opportunity to introduce these artists to the form, though I admit it’s very challenging. What I look for is someone who is excited to move in another dimension, to become a giant body of light, to take the time to develop the skills to be able to connect intimately with individuals in the audience.

The performers need to be gifted dancers who are able to move slowly and precisely with special care. I use the word “care” because the shadow of their hand will reach into someone’s face. If that move is too quick, it will be jarring for the audience. Each move needs to be extremely intentional and respectful.

No other form provides this closeness of contact with a hovering astral body. The dancer is on a stage, and her fingers caress the air while her shadow hand is at your cheek. The dancers cannot register this effect while they are performing it. They need to trust me as a director, and they trade out from dancer to viewer during rehearsal so that they can experience it for themselves.

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Source: https://fellowsblog.ted.com/how-to-create-...