Graphics Technologies

Summary

Graphics technology, which includes computer-generated imagery, has become an essential technology of the motion picture and video-gaming industries, of television, and of virtual reality. The production of such images, and especially of animated images, is a complex process that demands a sound understanding of not only physics and mathematics but also anatomy and physiology.

Definition and Basic Principles

While graphics technologies include all of the theoretical principles and physical methods used to produce images, it more specifically refers to the principles and methods associated with digital or computer-generated images. Digital graphics are displayed as a limited array of colored picture elements (pixels). The greater the number of pixels that are used for an image, the greater the resolution of the image and the finer the detail that can be portrayed. The data that specifies the attributes of each individual pixel are stored in an electronic file using one of several specific formats. Each file format has its own characteristics with regard to how the image data can be manipulated and utilized.

Because the content of images is intended to portray real-world objects, the data for each image must be mathematically manipulated to reflect real-world structures and physics. The rendering of images, especially for photo-realistic animation, is thus a calculation-intensive process. For images that are not produced photographically, special techniques and applications are continually being developed to produce image content that looks and moves as though it were real.

Background and History

Imaging is as old as the human race. Static graphics have historically been the norm up to the invention of the devices that could make a series of still pictures appear to move. The invention of celluloid in the late nineteenth century provided the material for photographic film, with the invention of motion picture cameras and projectors to follow. Animated films, commonly known as cartoons, have been produced since the early twentieth century by repeatedly photographing a series of hand-drawn cels. With the development of the digital computer and color displays in the last half of the century, it became possible to generate images without the need for hand-drawn intermediaries.

Computer graphics in the twenty-first century can produce images that are indistinguishable from traditional photographs of real objects. The methodology continues to develop in step with the development of new computer technology and new programming methods that make use of the computing abilities of the technology.

How It Works

Images are produced initially as still or static images. Human perception requires about one-thirtieth of a second to process the visual information obtained through the seeing of a still image. If a sequential series of static images is displayed at a rate that exceeds the frequency of thirty images per second, the images are perceived as continuous motion. This is the basic principle of motion pictures, which are nothing more than displays of a sequential series of still pictures. Computer-generated still images (now indistinguishable from still photographs since the advent of digital cameras) have the same relationship to computer animation.

Images are presented on a computer screen as an array of colored dots called pixels (an abbreviation of “picture elements”). The clarity, or resolution, of the image depends on the number of pixels that it contains within a defined area. The more pixels within a defined area, the smaller each pixel must be and the finer the detail that can be displayed. In the 2010s, modern digital cameras typically captured image data in an array of between eight and fifty megapixels. The electronic data file of the image contains the specific color, hue, saturation, and brightness designations for each pixel in the associated image, as well as other information about the image itself.

To obtain photorealistic representation in computer-generated images, effects must be applied that correspond to the mathematical laws of physics. In still images, computational techniques such as ray tracing and reflection must be used to imitate the effect of light sources and reflective surfaces. For the virtual reality of the image to be effective, all of the actual physical characteristics that the subject would have if it were real must be clearly defined as well so that when the particular graphics application being used renders the image to the screen, all of the various parts of the image are displayed in their proper positions.

To achieve photorealistic effects in animation, the corresponding motion of each pixel must be coordinated with the defined surfaces of the virtual object, and their positions must be calculated for each frame of the animation. Because the motions of the objects would be strictly governed by the mathematics of physics in the real world, so must the motions of the virtual objects. For example, an animated image of a round object bouncing down a street must appear to obey the laws of gravity and Newtonian mechanics. Thus, the same mathematical equations that apply to the motion and properties of the real object must also apply to the virtual object.

Other essential techniques are required to produce realistic animated images. When two virtual objects are designed to interact as though they are real, solid objects, clipping instructions identify where the virtual solid surfaces of the objects are located; the instructions then mandate the clipping of any corresponding portions of an image to prevent the objects from seeming to pass through each other. Surface textures are mapped and associated with underlying data in such a way that movement corresponds to real body movements and surface responses. Image animation to produce realistic skin and hair effects is based on a sound understanding of anatomy and physiology and represents a specialized field of graphics technology.

Applications and Products

Software. The vast majority of products and applications related to graphics technology are software applications created specifically to manipulate electronic data so that it produces realistic images and animations. The software ranges from basic paint programs installed on most personal computers (PCs) to full-featured programs that produce wireframe structures, map surface textures, coordinate behaviors, movements of surfaces to underlying structures, and 360-degree, three-dimensional animated views of the resulting images.

Other types of software applications are used to design objects and processes that are to be produced as real objects. Computer-assisted design is commonly used to generate construction-specification drawings and to design printed-circuit boards, electronic circuits and integrated circuits, complex machines, and many other real-world constructs. The features and capabilities of individual applications vary.

The simplest applications produce only a static image of a schematic layout, while the most advanced are capable of modeling the behavior of the system being designed in real time. The latter are increasingly useful in designing and virtual-testing such dynamic systems as advanced jet engines and industrial processes. One significant benefit that has accrued from the use of such applications has been the ability to refine the efficiency of systems such as production lines in manufacturing facilities.

Hardware. The computational requirements of graphics can quickly exceed the capabilities of any particular computer system. This is especially true of PCs. Modern graphics technology in this area makes use of separate graphics processing units (GPUs) to handle the computational load of graphics display. This allows the PC's central processing unit (CPU) to carry out the other computational requirements of the application without having to switch back and forth between graphic and nongraphic tasks.

Many graphics boards also include dedicated memory for exclusive use in graphics processing. This eliminates the need for large sectors of a PC's random access memory (RAM) to be used for storing graphics data, a requirement that can render a computer practically unusable.

Another requirement of hardware is an instruction system to operate the various components so that they function together. For graphics applications, with the long periods of time they require to carry out the calculations needed to render a detailed image, it is essential that the computer's operating system be functionally stable. The main operating systems of PCs are Microsoft Windows and the Apple macOS.

The huge amounts of graphics and rendering required for large-scale projects such as motion pictures demand the services of mainframe computers. The operating systems for these units have a longer history than do PC operating systems. Mainframe computers function primarily with the UNIX operating system, although many now run under some variant of the Linux operating system. UNIX and Linux are similar operating systems, the main difference being that UNIX is a proprietary system whereas Linux is open-source.

Motion Pictures and Television. Graphics technology is a hardware- and software-intensive field. The modern motion picture industry would not be possible without the digital technology that has been developed since 1980. While live-action images are still recorded on standard photographic film in the traditional way, motion picture special effects and animation have become the exclusive realm of digital graphics technologies. The use of computer generated imagery (CGI) in motion pictures has driven the development of new technology and continually raised the standards of image quality. Amalgamating live action with CGI through digital processing and manipulation enables film-makers to produce motion pictures in which live characters interact seamlessly with virtual characters, sometimes in entirely fantastic environments. Examples of such motion pictures are numerous in the science-fiction and fantasy film genre, but the technique is finding application in all areas, especially in educational programming. In addition, motion capture technology combines graphics with recorded human movement to create an animated character.

Video Gaming and Virtual Training. The most graphics-intensive application is video gaming. All video games, in all genres, exist only as the graphic representation of complex program code. The variety of video game types ranges from straightforward computer versions of simple card games to complex three-dimensional virtual worlds.

Many graphics software applications are developed for the use of game designers, but they have also made their way into many other imaging uses. The same software that is used to create a fictional virtual world can also be used to create virtual copies of the real world. This technology has been adapted for use in pilot- and driver-training programs in all aspects of transportation. Military, police, and security personnel are given extensive practical and scenario training through the use of virtual simulators. A simulator uses video and graphic displays of actual terrain to give the person being trained hands-on experience without endangering either personnel or actual machinery.

Social Context and Future Prospects

Graphics technology is inextricably linked to the computer and digital electronics industries. Accordingly, graphics technology changes at a rate that at minimum equals the rate of change in those industries. Since 1980, graphics technology using computers has developed from the display of just sixteen colors on color television screens, yielding blocky image components and very slow animation effects, to photorealistic full-motion video, with the capacity to display more colors than the human eye can perceive and to display real-time animation in intricate detail. The rate of change in graphics technology exceeds that of computer technology because it also depends on the development of newer algorithms and coding strategies. Each of these changes produces a corresponding new set of applications and upgrades to graphic technology systems, in addition to the changes introduced to the technology itself.

Each successive generation of computer processors has introduced new architectures and capabilities that exceed those of the preceding generation, requiring that applications update both their capabilities and the manner in which those capabilities are performed. At the same time, advances in the technology of display devices require that graphics applications keep pace to display the best renderings possible. All of these factors combine to produce the unparalleled value of graphics technologies in modern society and into the future. With advances in 3D computer graphics and products like smart glasses in the 2010s, graphics technologies have become even more immersive, allowing for a continually growing range of functions from education to game play. In 2022, Intel released a new graphics technology, mobile graphics cards. While the cards were designed for ultra thin laptops, the company also planned to release the mobile cards for desktops.

Bibliography

Abrash, Michael. Michael Abrash's Graphics Programming Black Book. Albany, N.Y.: Coriolis Group, 1997.

Brown, Eric. “True Physics.” Game Developer 17, no. 5 (May, 2010): 13-18.

Condon, Stephanie. "Nvidia's Latest Graphics Research Takes Images from 2D to 3D Almost Instantly." 2DNet, 25 Mar. 2022, www.zdnet.com/article/nvidias-latest-graphics-research-takes-images-from-2d-to-3d-almost-instantly/. Accessed 6 June 2022.

Jimenez, Jorge, et al. “Destroy All Jaggies.” Game Developer 18, no. 6 (June/July, 2011): 13-20.

Oliver, Dick, et al. Tricks of the Graphics Gurus. Carmel, Ind.: Sams, 1993.

Painter, Lewis. "Intel Arc Mobile Graphics Card: Everything You Need to Know." Tech Advisor, 10 Mar. 2022, www.techadvisor.com/article/744537/intel-arc-mobile-graphics-card-everything-you-need-to-know.html. Accessed 6 June 2022.

Ryan, Dan. History of Computer Graphics: DLR Associates Series. Bloomington, Ind.: AuthorHouse, 2011.