Issue link: https://digital.copcomm.com/i/14320
Scientific Visualization n n n n Recent History Tis year marks the 10th anniversary of the Rose Center for Earth and Space, which opened its doors at the turn of the millennium and houses the rebuilt Hayden Planetarium, originally established in 1935. Gone was the old optical star projector, and in its place was a next-generation visualization system consist- ing of the powerful Zeiss Mark IX optical sky projector and a digital dome system compris- ing an SGI Onyx 2 InfiniteReality2 and a Tri- mension video display with seven coordinated Barco high-resolution CRT projectors (five around the periphery and two for the center). “If you want to experience phenomenon in the night sky, explore the Orion Nebula, or see what colliding galaxies will look like 50 million years in the future, and visualize that scientific data in a meaningful way, you need a compel- ling set of tools,” says Bernhardt. “Tat is what we looked for when we started to develop the technology for the new Hayden Planetarium that opened in 2000.” Not long after, a more cost-efficient solu- tion—one using commercial hardware that took advantage of the revolutionary power of GPUs—replaced the Onyx as the museum’s visualization system. It was built around dual AMD Opteron 250 rackmount CPUs with Nvidia Quadro FX cards sporting G-Sync option boards. Te system would support multiple functions, including the visualization of real-time data presentation in the dome for lectures or the staff’s own previsualiza- tion needs, rendering the work for upcoming shows, and synchronizing the projection of the multiple images onto the 21-meter (69- foot) dome. Seven of the black-box PCs were devoted to visualization and projection, with an eighth serving as the master controller and as a backup when needed. In essence, this genlocked, swap-group envi- ronment uses inexpensive hardware to drive a high-bandwidth playback that only a few years ago required the use of a supercomputer. By dividing large data sets across multiple storage and computational sites, and running opera- tions on them simultaneously, these clustered computers can manipulate extremely complex data sets at phenomenal speeds. Te content for the shows, meanwhile, re- sides on an external SAN storage array. By uti- lizing that external ADIC StorNext file-sharing platform, the museum is able to play back ma- terial to the dome, while writing new content for production—without any interruption or compromise in service, says Bernhardt. Te dome itself is omnidirectional, with 429 seats surrounding the screen in a circular In the early universe, the first stars form from clouds of gas drawn together by the gravity of the mys- terious substance called dark matter. The Hayden team re-created this event using high-performance computing and visualization techniques, and incorporated it into the show Journey to the Stars. fashion. A six-channel projection system (now comprising Projection Design F30s situated around the circumference of the screen, in addition to a master, each paired to a media server) displays the imagery. In order to dis- play the large visuals used by the planetarium, the imagery is segmented and divided into six corresponding “slices,” and then synchronized, or “linked” together, to create one seamless, edge-blended picture. “Te Hayden’s current setup is limited by the projectors at this point, which show a 3k x 3k image at 8 bits,” says Bernhardt. “Our medium-term goal is 4.5k x 4.5k at 10 bits.” Despite the limitation of the present projec- tion system, the staff nevertheless began work- ing in higher bit depth on the graphics side, allowing for a higher dynamic range and the ability to do gamma adjustments without in- troducing a lot of noise into the imagery. Te group moved to 16-bit floating-point EXR and needed a projection system that could keep up with the graphics. Meanwhile, the museum’s recent shows, including Journey to the Stars and a previous show, Cosmic Colli- sions, were rendered at 4k x 4k resolution, to future-proof the content. “We wanted a computer system that could immerse the audience in content that has a Hollywood-style rendered look, but it is most important to remember that the imagery here is driven by real science, through simulation and visualization. And we wanted it to play in a theater that supports Broadway-style theat- rics,” Bernhardt explains. While the current system is state-of-the-art, the new projection system will be bleeding- edge—so much so that audiences will be able to see finely detailed imagery that had previ- ously been “invisible” to the general public. “We know the material is present; we can see it on our monitors [during previsualization],” says Bernhardt. “We work at the highest qual- ity and resolution so we can be as accurate as possible, and we know that the projectors will keep getting better and will be able to reveal more and more of the information. To that end, we use higher resolution and higher bit depth from the graphics side because we know that any flaws we have will also be revealed in the future with the new projection system.” Star-studded Animations Te latest development at the Hayden Plan- etarium is Journey to the Stars, which plays daily. Journey, nearly three years in the making, July 2010 39