Visualization Expanding Scientific and Engineering Research Opportunities Thomas A. DeFanti and Maxine D. Brown, University of Illinois at Chicago Bruce H. McCormick, Texas A&M University omputational science and engi- a tiny fraction of a given solution . That is, neering (CS&E) describes a it is impossible to investigate the qualita- researcher's use of computers to tive global nature of numerical solutions. simulate physical processes. CS&E paral- Visualization holds With the advent of raster graphics, re- C can convert entire fields of vari- lels the development of the two other searchers modes of science: theoretical and experi- great promise for ables (representing density, pressure, ve- mental/observational. computational science locity, entropy, and so on) to color images. In addition to new methodologies, new The information conveyed to the re- technologies or mathematical tools have and engineering, searcher undergoes a qualitative change spurred the scientific revolutions. For because it brings the eye-brain system, example, calculus allowed Newton to provided we can meet with its great pattem-recognition capabili- codify the laws of nature mathematically the immediate and ties, into play in a way that is impossible and develop analytic methods for solving with purely numeric data. simple cases. Similarly, the development long-term needs of For example, an observer instantly sees of the van Neumann computer architecture the vortices, shock systems, and flow pat- gave scientists the ability to solve the dis- both toolmakers and tems in a visualization of a hydrodynamic cretized laws of nature for general and tool users. calculation, while these same patterns are complex cases. invisible in mere listings of several CS&E now relies heavily on scientific hundred thousand numbers, each repre- visualization to represent these solutions, senting field quantities at one moment in enabling scientists to turn mountains of time. When computing a space-time solu- numbers into movies and graphically dis- tion to the laws of physics, the particular play measurements of physical variables tion of the National Science Foundation numeric quantities at each event in time- in space and time. This article explores the report Visualization in Scientific Comput- space are not important; rather, what is convergence of science and visualization, ing,' represents much more than that. Visu- important is understanding the global in support of its successful growth and alization is a forth of communication that structure ofthe field variables that consti- development. transcends application and technological tute the solution and the causal intercon- boundaries. nections ofthe various components of that solution. What is scientific A tool for discovery and understand- visualization? ing. The deluge ofdata generated by super- A too] for communication and teach- computers and other high-volume data ing. Much ofmodern science can nolonger Computer graphics and image process- sources (such as medical imaging systems be communicated in print. DNA se- ing are technologies. Visualization, a term and satellites) makes it impossible for quences, molecularmodels, medical imag- used inthe industry since the 1987 publica- users to quantitatively examine more than ing scans, brain maps, simulated flights 12 0018-9162/89/OBOO.OO12f01 .00 019891EEE COMPUTER through aterrain, simulationsof fluid flow, The visualization report recommends Tool users' short-term and so on, all need to be expressed and the development of a federally funded ini- taught visually over time. To understand, tiative providing immediate and long-term needs discover, or communicate phenomena, funding of both research and technology scientists want to compute the phenomena developments (see Table 1).' Research Every researcher requires a personal her desk over time, create a series of images that developments are the responsibility oftool computer orworkstation on his or . illustrate the interrelationships of various users - experts from engineering and the connected with a remote supercomputer parameters at specific time periods, down- discipline sciences who depend on compu- However, not all scientists require the power. Hence, a load these images to local workstations for tations for their research. Technology same level of computing environment is begin- analysis, and record and play back one or developments are handled by toolmakers three-tiered model categorizes visualiza- more seconds of the animation. - the visualization researchers who can ning to emerge that According to the visualization report, develop the necessary hardware, software, tion systems by such factors as power, "We speak (and hear) - and for 5000 and systems. cost, and software support. years have preserved our words. But, we cannot share vision. To this oversight of evolution we owe the retardation of visual compared to language. communication Table 1. Recommendations for a national initiative on visualization in scientific shared communication Visualization by computing. would be much easier if each of us had a CRT in the forehead."' Short-term Needs Long-term Needs Our CRTs, although not implanted in our foreheads, are connected to computers Tool users: Funding to incorporate Funding to use model of that are nothing more than extensions Computational visualization in visualization environments our brains. These computers, however, scientists and current research might not be in the same room with us. engineers They could be down the hall, across town, or across the country. Hence, the ability to Toolmakers : No funding necessary Funding to develop model communicate visually - and remotely - Visualization visualization environments on with computers and each other depends scientists and per- the accessibility, affordability, and engineers formance of computers and computer net- works. Table 2. Visualization facility three-tiered hierarchy. Model A Model B Model C Hardware Supercomputer or Minisupercomputer or Advanced workstations (mini-/ super image computer image computer micro- image computer Bandwidth (potential >109 10'-108 interactive rates, bits/second) Location (where users Machine room Laboratory on a high-speed Laboratory on a national/ interact with the (at the center) local area network regional network display screen) Software (in addition Commercial packages for Commercial packages Commercial packages and todiscipline-specific output only (no steering). are mostly output only. Some tools are widely available data generation and Research required to interaction is becoming for both computation and processing) develop interactive steering available. Research required interaction. Research required capabilities to improve discipline- , in languages, operating specific interaction systems, and networking Administration Strength: Support staff Discipline-specific Decentralization visualization goals Weakness : Centralization Small support staff No support staff August 1989 13 Workstations. Researchers need work- dows on the screen, and scientists must be als are for personal analysis, information stations with access to supercomputers for able to "cut and paste" between the super- sharing among peers, or presentations in computerand applications running on their formal surroundings, equipment for pro- " immediate access to local graphics local machines . ducing photographs, slides, videotapes, or capabilities, laser disks needs to be in place and as easy " networked access to supercomputers, Access to supercomputers. Scientists to use as sending text files to a laser printer. and need to transfer data to and from a main Scientists need the ability to create ad " hard-copy recording. computation device, but today's networks hoc graphics to verify the integrity of their Local graphics . Workstations, mini- are too slow for use in visualization. Some simulations, gain insights from their analy- computers, and image computers are sig- temporary techniques reduce the demand ses, and communicate their findings to nificantly more affordable than supercom- for high bandwidth, such as off-peak im- others . Low-cost animation facilities puters, and they are more powerful and age transmission, image compression, should be connected to every user worksta- effective visualization tools. There are image reconstruction from abstract repre- tion so researchers can make scientific already some 20 million personal comput- sentations, and local image generation . "home movies" with little effort . High-end ers and workstations in the United States, Networking is therefore as critical as visualization capabilities and facilities compared with about 200 supercomputers . computer power in helping scientists . also should be available at all research Workstation users are increasingly treat- centers; high-end graphics become impor- ing supercomputers as one of many win- Hard-copy recording. Whether the visu- tant for presentation and publication of Low-cost, visualization-compatible workstations and networks Our ability to communicate visually and remotely with ficiently used to run complex simulation codes, the output of supercomputers and each other depends on which is numbers. With access to graphics, researchers can convert numbers to pictures to qualitatively examine the global (1) the ease with which we can use our office/home com- nature of their simulation output. Graphics can be made avail- puters to connect with the outside world, receive and transmit able on the host machine or, more efficiently, on the