Issue link: https://digital.copcomm.com/i/14320
n n n n Scientific Visualization was completed by the facility’s astrophysics department with direction from Carter Em- mart, director of astrovisualization, who, ac- cording to Bernhardt, “is a master at figuring out how to translate the science into something both accurate and compelling to look at.” Journey follows Cosmic Collisions, which, along with other space shows produced by the museum, is licensed and featured at mu- seums and planetariums around the world, including the Gates Planetarium in Denver (see “Sky High,” pg. 44). Tat show illustrates how, through explosive collisions, our solar system was shaped. Te remarkable events por- trayed in Journey and Collisions were generated through simulations and visualizations requir- ing phenomenal power, and then processed with complex tools and techniques. In nearly all of the shows’ sequences, the group had to mathematically describe and then computa- tionally model the intricate events depicted; then, the numerical simulations (data sets) had to be turned into graphic animations. Te space-show production team is set up similar to a typical film production crew, with a director, content creation group, and VFX supervisor (in this case, a visualization direc- tor). “We run through the same type of story- board and iterative dailies viewing processes you would have on a CG film,” explains Bern- hardt. “Only on a CG film, when it is time to look at dailies, you just pop over to the view- ing area. Our viewing area is the dome, which is used from 10:30 am to 5 pm every day, so we work a lot of atypical hours.” Where does this space-age imagery come from? For Journey and its other shows, the de- velopment team of scientists and visualization experts use various digital content creation tools, Usually, the shows require ultra-special- ized data from a number of scientific sources throughout the world, including NASA, which use scientific simulations to describe the complex physical events in the shows, such as the impact of an asteroid hitting Earth, as depicted in Cosmic Collisions. “Whenever pos- sible, we use real simulation data,” says Ber- nhardt. “Tat is one of the hallmarks of our shows. It is created by collaboration, but with 40 July 2010 The events shown in Cosmic Collisions are based on simulations of extremely complex data sets. strong scientific involvement both internally and with our collaborators. Te science rigor starts at the very top and percolates through- out the entire production process.” Te pro- duction team then translates the data sets into visualizations that are accessible to learners of all ages. To that end, the museum staff wrote mul- tiple pieces of software that would transform the complex, dynamic data sets, such as 2D image files taken by NASA’s Hubble and Spitzer space telescopes, into 3D volumes moving through time. “When you look at a Hubble picture, you are looking at a snapshot of data. We can fly up to a 2D Hubble pic- ture in the dome, but we cannot fly into it. It’s flat,” explains Bernhardt. “We model what we see in the picture, so it becomes 3D, and now we can move the camera through it to give the visitor the experience of flying through or around the object.” When the in-house staff is called upon to generate 3D models, it does so using Auto- desk’s Maya or Side Effects’ Houdini for mod- eling and managing the camera animation. On the software side, the rendering is usually done with Pixar’s RenderMan, though at times the group’s custom volumetric tool, mPire, is needed for certain phenomena (such as stars and clouds, giving the imagery an accurate and beautiful “cosmic look”), while the in-house developed Spot is used to generate star fields. “Tat renderer (mPire) was the result of col- laboration we did on our first space show with the San Diego Supercomputer Center, and we dusted it off for large sections of Journey to the Stars, creating some amazing volumetric renderings that were efficiently done on the new Intel quad-core boxes,” says Bernhardt. “For that first show, we ran it on a giant Sun cluster for some ungodly amount of time. But with the modern processors, we were able to render a test scene on just a few processors in a couple days.” Image compositing is done using Te Foundry’s Nuke, with Seriss Rush managing the renderfarm. According to Bernhardt, the production chain is mostly Linux-based. As a result of the setup, the TDs and graphics artists use a Linux-based version of Maya running on their Dell graphics workstations. Te hardware ren- dering also runs under Linux within a cluster of more than 100 processors running the Fe- dora operating system on PSSC Labs rack- mount computers. More recently, the digital dailies function was replaced by a newer image generator, for playing content back to the dome and for re- viewing the content for the dailies when mak- ing upcoming shows. Tis latest system, which is Windows-based and installed by Global Im- mersion, runs Delta software from 7th Sense. Te playback system, with its fast processing power and storage, pulls the necessary band- width that enables the planetarium staff to view the rendered content in real time without compression. As a result, the group can look at renders in an artifact-free state and make content decisions quickly. “Tis ability to do digital dailies is invaluable,” says Bernhardt. Real-time Reality After the planetarium went digital a decade ago, development of its real-time environment seemingly progressed at the speed of light—a perfect scenario for, well, flying around the universe. To that end, the American Museum of Natural History curated and now maintains the Digital Universe, an atlas database of all the known stars, galaxies, and objects in the ob- servable universe—a 3D mapping of the uni- verse, if you will, containing vital data, such as the location of the planets and stars, brightness levels, proximities, and so forth. It is constantly updated as NASA and other researchers con- duct new surveys and make new discoveries. Te planetarium staff uses the information contained within the Digital Universe as the basis for a significant part of its shows, utiliz- ing the database in collaboration with a real- time data viewer as a previs tool to produce accurate, rough content cuts—working out complex camera paths, for instance. Custom