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5 CHAPTER TWO VISUALIZATION OVERVIEW WHAT IS VISUALIZATION? allow participants to better view specific locations and their proposed alternatives to obtain greater understanding. Visualization is a simulated representation of proposed trans- portation improvements and their associated impacts on the surroundings in a manner sufficient to convey to the layperson the full extent of the improvement (2). HISTORY OF VISUALIZATION WITHIN TRANSPORTATION DESIGN COMMUNITY The use of visualization to understand complex issues such as proposed designs is not a new phenomenon. It has been As the transportation design community matured during the used in maps and drawings for centuries. A famous example 20th century, visuals were used to convey proposed road- of this is Charles Joseph Minard's map of Napoleon's inva- way designs. Before the advent of computers, traditional sion of Russia in 1812 (Figure 1). This map clearly conveys artist hand renderings and physical models (Figure 2) were troop movement, size, and loss of life during the campaign created and used primarily for stakeholder approvals. into Russia (3). Although effective, hand renderings only provided a limited number of viewpoints for the project. They were also based Visualization can accelerate conceptual approvals, identify on artistic interpretation and thus were only approximate in less-than-obvious design flaws or opportunities, and ultimately their accuracy. Physical (i.e., scaled) models provided an reduce development costs before commencement of construc- excellent and accurate representation of the overall project tion. It has the ability to help with the analysis of multiple site, but lacked the detail necessary to fully comprehend the design elements, such as proposed buildings, roadways, and design. They were also time consuming to create, expensive underground utilities. Seeing the proposed design in three- to build, and inflexible to deal with the changes of a typical dimensional (3-D) instead of a series of two-dimensional (2-D) project. plans and elevations increases overall understanding, which can translate into schedule and budget savings. The nature of Since the inception of CADD (computer-aided design and the technology provides the capability for quicker response drafting), computerized visuals have been created by the trans- times in implementing design changes. The technology can portation design community. The CADD discipline can trace be used throughout the life cycle of a project plan--from the its beginnings to the Sketchpad system developed by Ivan process flow of value engineering, to the project development Sutherland in 1963 (4). Sutherland was able to connect the dis- and environment study phase, to design and construction. play capabilities of the cathode ray tube with the computational Visual tools can provide greater communication and concise abilities of the computer, and the interactive process with the understanding, which in turn can lead to quicker acceptance or light pen made it possible to create a system for designing approvals. mechanical parts. Sutherland's system prompted automotive and aerospace companies to take notice and start their own A major strength of visual tools is their ability to clearly projects to try to harness the power of the computer for their convey design issues. Designers will have the ability to view design needs. The late 1960s saw a flurry of activity in the their concepts from multiple viewpoints, including view- CADD-related sector. Turnkey companies such as Calcomp, points that are not feasible with standard photographic meth- Computervision, and McAuto started creating and marketing ods. Critical issues such as roadway aesthetics, vertical and software or hardware for this industry. These CADD-based horizontal alignment fit, traffic flow, and line of sight can be visuals ranged from simple 2-D plots of plans and sections to identified. The general public can also obtain a greater under- 3-D renderings of proposed elevations. standing of the project by viewing the proposed changes from a potentially unlimited number of viewpoints. Public By the mid to late 1970s, CADD modeling was available outreach and support can be more effectively achieved. through such programs as Intergraph's Interactive Graphics Although traditional methods of presenting 2-D design plans Design Software (Figure 3). These applications ran on and charts for high-profile projects have often created addi- expensive mainframe systems. Because of the limitation of tional misunderstanding because these methods do not fully hardware processing speeds (68k), software capabilities, and convey impacts in basic terms that the average person can the expense to operate these systems, 3-D visuals were diffi- visually understand, 3-D and other new visualization tools cult to achieve. The results were simple, shaded models that
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6 FIGURE 1 Charles Joseph Minard's map of Napoleon's march to Moscow during the invasion of Russia in 1812. (Courtesy : Graphics Press.) could only be created by an experienced CADD operator. became more sophisticated, allowing users to design and model Throughout the 1980s, CADD primarily ran on mainframe much more effectively in 3-D. Autodesk's 3-D Studio and computers. Bentley Systems' MicroStation, combined with other vendors, now offered integrated and affordable advanced 3-D modeling In the early 1990s, hardware and software technologies and rendering capabilities. rapidly advanced. Personal computers (PCs) were slowly replacing the mainframe-based workstations. PCs primarily To complement the CADD modeling, rendering, and ani- used the Microsoft Windows operating systems, which helped mation capabilities of transportation agencies, other software enable software manufactures such as Autodesk and Bentley applications have been written. Presentation graphic pro- Systems to develop CADD applications for the PC. For the first grams have simplified and improved how presentations are time, designers and engineers could create CADD drawings created and shown. For example, they have simplified the and renderings on an affordable workstation platform. As the process of creating 35-mm slides and presenting them in a hardware technologies for desktop PCs advanced, new soft- slide presentation. The steady advancement of other programs ware tools were being developed that made it easier to create such as photo-editing applications has enabled visualization computerized visuals. By the early 2000s, CADD applications specialists to create seamless photo-simulations that blend the FIGURE 2 Physical model of the Corning Bypass project. (Courtesy : Bergmann Associates.) FIGURE 3 Intergraph workstation--1978.