Waterfalls, the next movie screen? AquaLux 3D, a new projection technology developed at Carnegie Mellon University's Robotics Institute, can target light onto and between individual water droplets — enabling text, video and other moving or still images to be displayed on multiple layers of falling water.
"In contrast to existing technologies for projecting images onto water surfaces, AquaLux 3D makes it possible to create three-dimensional images in water by using multiple layers of precisely controlled water droplets," said Srinivasa Narasimhan, associate professor of robotics. "By combining the droplets with clouds of mist, it would be possible to create unique 3-D effects for theme parks, exhibitions and interactive games that don't require special eyeglasses to view."
The researchers have used the water drops to display video images, text, a simulation of fish swimming in an aquarium, alternating sheets of solid colors and even a multi-dimensional version of the video game Tetris.
"The beauty of water drops is that they refract most incident light, so they serve as excellent wide-angle lenses that can be among the brightest elements of an environment," said Narasimhan, who developed the display with Takeo Kanade, professor of computer science and robotics, and Peter Barnum, a Ph.D. student in robotics. "By carefully generating several layers of drops so that no two drops occupy the same line-of-sight from the projector, we can use each drop as a voxel that can be illuminated to create a 3-D image."
The researchers will discuss AquaLux 3D at SIGGRAPH, the 37th International Conference and Exhibition on Computer Graphics and Interactive Techniques, in Los Angeles, July 27.
Narasimhan said work on the display technology was an outgrowth of efforts to develop an LED automobile headlight system for driving in rain at night. To eliminate the headlight reflection that can make it difficult for drivers to see in rainy conditions, they explored ways to control light so that as many rays as possible would shine between raindrops.
"What we realized is that it was much easier to shine light on the drops themselves," he said.
One unique aspect of AquaLux 3D is the potential for physical interaction, Narasimhan noted.
"People can touch the water drops and alter the appearance of images, which could lead to interactive experiences we can't begin to predict," he said. "We look forward to the day when creative people can fully explore the potential of this display."
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