The opening sequence to the award portion of the evening began with a woman walking down the aisle toward the stage, holding the coveted Knight of Illumination award - a hand crafted sword. As she walked onto the stage, the sword was suddenly bathed in the light of two Clay Paky Sharpys, positioned on either side of the stage and tracking the sword to centre stage with perfect precision. When guests realized that these were not followspots, and there were no followspot operators, they wondered: How did they do that?
CAST BlackTrax is an Ethernet-based, powerful, fast, and accurate solution that tracks objects or people in a defined 3D 'Space' and delivers the dynamic positional data in realtime in up to 6 Degrees of Freedom - the usual x, y, z, plus roll, pitch & yaw - to 3D audio, moving lights, robotic cameras, and media technologies, using a BlackTrax Beacon which emits a virtually invisible infra red light via the LED that is seen by BT's proprietary, custom designed camera system which delivers the positional data to the BTServer.
A tiny wireless radio in the BTBeacon streams the additional data for 6D -- roll, pitch, and yaw -- as well as redundant 3D backup. The onboard gyroscope communicates the orientation of a moving piece or performer at over 250 frames per second. Control can be located up to 100 feet (30m) away with ΒΌ" tracking accuracy.
"The set up for the crew was pretty straightforward," says Gil Densham, president of CAST. "A BTBeacon was placed on the sword and then six tracking cameras were positioned on the truss - four at front of house, one stage left and one stage right. We focused and calibrated them and that's all -- tracking was running.
"Then we calibrated the Sharpys to be used and everything was ready. We worked with Alex Passmore LD for the show, he built a ballyhoo which allowed the girl carrying the sword to walk in, and the Sharpys picked her up and stayed with her so everyone could see her presenting the sword. The lights were positioned so that shadows of the Sharpys and could be seen. It all worked flawlessly - just like followspots."
(Jim Evans)
