Shanghai Surprise: The Ball Grid Array At The World Expo

In January 2009, 16 of the largest private corporations in China decided to demonstrate to the world that China’s attitude toward private enterprise is changing, and the economy had opened to entrepreneurs. They selected the 2010 World Expo in Shanghai as the platform for this statement to both the Chinese population and visitors from around the world. They were looking for a unique and original form of expression that was both entertaining and representative of the world-class caliber of their companies. This consortium of companies decided to finance the Chinese Private Enterprise Pavilion, dubbed the “Dynamic Matrix.”

The Private Enterprise Pavilion group reached out to Japanese firms ADK and Murayama to develop a concept that would impress the world. At that point, the opening of the Expo was only 12 months away, which presented an extremely tight timeframe for the design, construction, and installation of a cutting-edge attraction. After seeing the work done in Macau at the City of Dreams Resort on the award-winning Dragon’s Treasure in the 360° Bubble Theatre (“Wave of the Future,” LD, October 2009), Murayama contracted Fisher Technical Services, Inc. (FTSI) to provide the core technology for an as-yet-undefined feature. FTSI, the Las Vegas-based entertainment automation company known for its Navigator software and automation products, had mechanical design and fabrication services, automation software, and a show control system featured extensively in the Macau show.

By July 2009, the creative team settled on a kinetic sculpture for the centerpiece of the pavilion using a grid array of 1,008 150mm diameter spheres, each suspended and motivated by its own miniature winch. Although three-dimensional “dancing sphere” effects have been developed for other attractions and displays in the past, FTSI was tasked with an implementation that was larger, faster, more responsive, and easier to program than any previous version. Work commenced on the mechanical, control, and software design in August 2009, with final acceptance testing scheduled for only 120 days later.

The concept for the sphere array was similar to that of a “pincushion” toy, where 3D shapes can be impressed into a grid of numerous closely spaced elements that each move independently in a vertical linear plane. To achieve this as a large-scale suspended design, the spheres are arranged in a flat grid that measures 18'x56' (6m x 18m), with each sphere spaced on 12" (30cm) centers. To provide a high degree of dynamic range and performance capacity, each miniature winch is capable of speeds up to 9.8' (3m) per second. With this combination of geometry and mechanical capability, the array can create a virtually infinite number of shapes, movements, and effects in three dimensions by making the balls move to different heights and at different speeds.

In addition to high-performance requirements on the mechanical end, FTSI also needed to provide an intuitive means of programming 1,008 individual winches so that the client’s creative team would have unlimited freedom to explore static shapes, waveforms, and free-flowing dynamic animation without the need for programming skills. For this effect, FTSI programmed the individual movement of each of the 1,008 spheres using simple video files. A 1,008-pixel grayscale video frame was constructed, with each pixel corresponding to a single winch, so playback of a video file within this frame with a simple color gradient from white to black would produce a spread of spheres from the lowest point of travel to the highest, depending on the grayscale value of each pixel in each frame. The gray value of each pixel in the video file controls the height of each sphere, and the speed of the grayscale transition controls the speed of ascent or descent.

This elegant interface allowed the creative team to use any video compositing tool to create the shapes, effects, and motion profiles they desired in a live dynamic setting, with no additional programming or rendering time required. A pre-visualization environment was built to allow programmers to view the movement in simulation before being played on the actual array. The media playback system for communication of gray values to Navigator was created in conjunction with Richard Bleasdale, creator of Catalyst Media Server software.

FTSI engineer Jason Goldenberg integrated the data stream from Bleasdale’s software into the FTSI Navigator motion control system using its existing communication tools. “The sphere array is like a giant TV set, and our software acts as the DVD player,” he says. “Actually, with the bit rate we are using, it’s more like a Blu-ray player.”

Creating, controlling, and distributing position data from video files to 1,008 winches quickly and accurately generated new challenges for FTSI. The sheer volume of data to be created, verified, and distributed required precision timing and bandwidth beyond what you’d normally encounter in a typical theatrical or show control system. The standard Navigator communication backbone incorporates a high-speed, realtime deterministic protocol, but in the case of the sphere array, the communication capabilities of the miniature motors also had to be taken into account. To provide a solid, realtime, high-speed interface to the individual motors, Navigator was set up in its “EtherCAT Master” mode to distribute data via an extremely high-speed realtime industrial Ethernet-based protocol, rather than Navigator’s standard protocol. Motion control messages were distributed to the array groups via this method and then converted locally to CANbus, the native protocol of the motors that were used. This provided the high-speed data backbone required for accurate and coordinated motion control, without requiring any custom motor control construction.

While the array program is running, the motion profiles are dynamically created on a frame-by-frame basis. First, the Apple QuickTime video file begins to play on an Apple Xserve computer. The Xserve interprets the pixel grayscale into position data and then transmits that data via Art-Net to the Navigator motion control system. Navigator then repackages the Art-Net “position” data, as well as additional motor control data, into a new EtherCAT packet, which is then distributed to CANbus gateways on the grid. It takes less than 25 milliseconds for the pixel data to be represented as motion on a winch. The volume of data on the network during motion is over 4Mbps or the equivalent of three maxed-out T1 lines.

For day-to-day operation, Goldenberg and Nathan Cross, another FTSI engineer, collaborated on designing a multi-screen touch-based interface to allow pavilion operators to run the show on their own. Using Navigator’s built-in custom screen and control construction tools, Cross and Goldenberg developed an aesthetically pleasing and simple interface that can trigger the complex system at the push of a button. The interface comprises several screens that are accessed with a common navigation bar, similar to a web page. Styles and button placement are carried from page to page to make the experience as intuitive as possible. Help screens are also integrated into every page.

In addition to the sphere array, FTSI also provided the show control system for the attraction, using the show control programming tools incorporated into Navigator in conjunction with an FTSI SCU-1 Show Controller. The SCU-1 integrates the array with the projection, lighting, and sound system, and provides the master clock control and full sequence programming for the entire attraction. Imagica designed the lighting and video for the installation.

The entire array was manufactured, assembled, and tested in FTSI’s production facility in Las Vegas and later broken down, packed up, and shipped to Shanghai. The final installation commenced in early February, providing only three months to assemble, program, and integrate. The FTSI team included Towako Yagura, FTSI’s vice president of business development in Asia, as well as McLane Snow, Casey Roche, James Irwin, and Tom Kong.

The seven-minute show was described by one audience member as “perfect” and by another as “the most beautiful thing ever.” Even the vice president of China himself declared it the best attraction at the World Expo. With a joint collaboration of Chinese, Japanese, and American talent, the Chinese Private Enterprise Pavilion is a resounding success.

The World Expo will remain open until October.

Among various occupations, Sam Fleming is a freelance writer specializing in exotic technology in distant lands. Although primarily focused on high performance motorcycles, he has made periodic contributions to Live Design regarding installations by Fisher Technical Services, Inc., where he serves as a consigliere.