The dancers from the experimental group Capacitor have put on some pretty wild outfits in their time.
In one piece, dancers wore lightbulbs on their heads; in another, a dancer wore a helmet bedecked with flaming torches.
So it must not have seemed too bizarre for five Capacitor dancers to don hats and spandex suits covered with tiny reflective balls one day in March.
In any case, the ball-covered outfits are normal office wear at the House of Moves motion capture studio in Los Angeles, where they were about to have their movements recorded.
Motion capture is a technique for recording human motion to apply it to animated characters. It is mostly used in creating video games, but it is becoming increasingly popular in film animation, commercials, music videos and other media such as dance performances.
It took four hours to prepare the dancers' suits that day, but it was well worth it for the final result two months later: five stunning animations of the dancers performing as "fire," "water," "metal," "earth" and "wood." The animations are used in the company's new dance piece, Avatars.
Capacitor director Jodi Lomask chose to use motion capture animation in Avatars to transcend the limitations of a dancer's body.
"Instead of me just trying to dance like water, we can apply my movement directly to the texture of water," she said.
In the animation, she appears as a glossy, semitransparent blue figure dancing on a sea of gently rippling waves.
"The imagination has no limits," she said. "I would want to move like a mountain, I would like to move like fire, I'd like to move like anything.... With motion capture animation, you can go where your body can't go."
To prepare to collect the motion data at the studio, House of Moves artists covered each dancer with reflective balls called markers, attached to their suits with velcro. The markers would be used to help cameras in the studio record the dancers' movement.
It's a time-consuming process because the motion capture artists "have to make sure (the markers are) fitting on all your joints perfectly," Lomask said.
Dancer Chih-Ting Shih is so slender that none of the studio's shirts fit her. "They had to jimmy up something," Lomask said. "They had to put bands around her arms rather than having her wear a shirt, because if the shirt moves, the marker moves."
The dancers' props were also covered with markers. Shih, who uses a metal sword in the piece, had to switch to a wood sword because the metallic reflection would have distorted the motion capture data from the markers. Zack Bernstein, who juggles machetes, had to switch to clubs for the same reason.
When the preparation was done, each dancer performed a solo in front of 18 cameras mounted on a steel grid around the perimeter of a stage area.
The Vicon 8 cameras used at House of Moves are specially designed for motion capture, and the only information they pick up is the movement of the reflective markers. They are very high resolution -- 1-1.2 megapixels -- and shoot at 120 frames per second.
The data was reconstructed using Vicon software, which "takes the images from each camera, and it computes where it is in 3-D space, so it can change 2-D images from the camera to 3-D," said Garret Gray, one of the main artists involved in the project.
For each performer, the artists labeled the marker data by location on the body, creating what looks like a green stick figure.
Then Gray and another artist, Josh Ochoa, worked for two weeks in an editing tool called Diva to process the labeled marker data to make what is called a "skeleton."
The skeleton "represents the proportions of the body," Gray said. The markers determine the proportions of the skeleton, and the motion capture data drives its movement.
Most House of Moves projects end with creating the marker data or the skeleton. Typical clients such as video game and film companies outsource the motion capture work, but complete the animation in-house.
With Avatars, Gray and Ochoa had the rare opportunity to see the project all the way through to creating the final animations.
Both artists have done 3-D animation for years and continue to do it as a hobby, although it's not the focus of their jobs. "We're completely insane for this kind of stuff," Ochoa said.
After consulting with Lomask and Bernstein about the look and environment for each character, they began working on the animations in 3-D software Maya.
First they created a mesh model showing the geometry of the character's outer form. They applied the model to the skeleton and imported the motion file on top of it to bring the animation to life. Then they created the look of the animation by adding lighting, texture and -- in the case of the fire animation -- fire particles.
Though wood props were used on the day of motion capture, the animators worked from photos of a metal sword and machetes to create those objects for the final animations.
The animations are used in the Avatars dance piece to help introduce each of the five main characters before a fight scene.
Each dancer is transformed into the element he plays. For example, the "metal" character is a shiny silver figure juggling machetes. While he may resemble a robot, he moves with a dancer's grace -- because his movements mimic performer Zack Bernstein.
In the future, Lomask would like to use not only the final animations of the elements, but also the labeled marker data that look like stick figures. "We're interested in the whole 'exposing the tech' as well as accentuating the tech in our visuals," she said.
At the other extreme, she also plans to create a more immersive audience experience by developing versions of the animations that look just like the performers -- and dropping them into a video game.
"I thought that would be a great way to bring the audience in," she said. "Have a bunch of consoles set up, and they could be playing us."
