Showing papers on "Computer graphics published in 1972"

Computer generated animation of faces

Abstract: This paper describes the representation, animation and data collection techniques that have been used to produce "realistic" computer generated half-tone animated sequences of a human face changing expression. It was determined that approximating the surface of a face with a polygonal skin containing approximately 250 polygons defined by about 400 vertices is sufficient to achieve a realistic face. Animation was accomplished using a cosine interpolation scheme to fill in the intermediate frames between expressions. This approach is good enough to produce realistic facial motion. The three-dimensional data used to describe the expressions of the face was obtained photogrammetrically using pairs of photographs.

Winged edge polyhedron representation.

Abstract: A winged edge polyhedron representation is stated and a set of primitives that preserve Euler''s F-E+V = 2 equation are explained. Present use of this representation in artificial intelligence for computer graphics and world modeling is illustrated and its intended future application to computer vision is described.

A System to Generate a Solid Figure from Three View

Abstract: Three view type drawing has been used widely for a long time, and it plays an important role in the field of design engineering. Recently, computer graphics has been developed and applied to practical use, but there are many serious problems remaining unsolved, for example, problems concerning the method to feed the three dimensional information accumulated as a three view type drawing into a computer and so on.In this paper, the author presents a formulation of the process to generate a solid figure from a three view type drawing automatically by machine. According to this formulation, a practical system was built up for the case of polyhedra. Executing several experiments the auther confirmed the effectiveness of this formulation. He points out a "Ghost Figure Problem" of a wired figure obtained during the procedure of this system and presents a method to solve it. Furthermore, he proposes a method to solve a "Hidden Line Problem".

The Efficiency of Computer Algorithms for Plant Layout

Abstract: This paper presents the results of comparing experimentally the performance of four of the more promising computer algorithms for the plant layout problem. CDC 3600 computer programs are tested wit...

The impact of computer graphics.

Abstract: This article outlines some of the problems associated with the use of computer graphics and describes some applications in the physical and biological sciences.

Computer graphics matrix multiplier

Abstract: A matrix multiplier is disclosed for rotating, translating, and scaling multi-dimensional drawing definitions (vectors), the system having particular applicability to the field of computer graphics. The multiplier registers an additional dimension over that of the vectors undergoing computation, whereby to accomplish both the transformations of translation and rotation. Specifically, a multiplier is disclosed to accommodate a four-by-four matrix for use in three-dimensional transformations. Furthermore, the multiplier incorporates a cubic-array register for registering plural matrices as a push down stack, along with structure for variously delivering elements therefrom. Individual matrices may be multiplied to provide composite transformations. The system also incorporates structure for providing curve and surface information by iterating difference equations.

The use of the inner zone electron model AE-5 and associated computer programs

Abstract: A users guide to the inner radiation zone electron model AE-5 is introduced. The guide covers a description of the model, the forms in which it is available, directions on how to use the model, and a discussion of its limitations. Computer programs MODEL and ORP are described. These are major programs needed to use the electron models AE-4 and AE-5 and the smoothed proton models.

Microprogramming for computer graphics

Abstract: Interactive computer graphics (graphics) is the construction, storage, retrieval, manipulation, alteration and analysis of pictorial data, using an on-line display console with manual input (interaction) devices. Among such input devices are the alphanumeric and function keyboards for typing text and activating preprogrammed subroutines respectively, and the light pen and data tablet for identifying and entering graphic data by means of pointing and drawing.

Visual simulation of dynamic three dimensional systems using the vector network

Abstract: This paper describes briefly a digital simulation program developed at the University of Waterloo, Canada. The program accepts the description of a dynamic three-dimensional mechanical system as input (presently limited to particle masses) and then formulates and integrates the equations of motion of the system. The resulting dynamic response is displayed on a CRT screen for observa tion. The theoretical basis for the program is the vector-network model, a recently-developed formula tion process based on graph theory. The computer graphics subroutines include a novel package for previewing and photographing the dynamic sequences on 16-mm motion-picture film. With some further development, the program could become a useful engineering tool for the design of dynamic mechanical systems.

Pictorial pattern recognition and the phase problem of x-ray crystallography

Abstract: The availability of interactive, three-dimensional, computer graphics systems coupled to powerful digital computers encourages the development of algorithms adapted to this environment. Pictorial pattern recognition techniques make possible a number of approaches to X-ray structure determination based on molecular model building, i.e. the use of chemical information to frame “structural hypotheses” which can computationally be tested and refined by reference to the experimental data.Application of standard pattern recognition algorithms is hindered by the fact that the cross-correlation between a model and the correct structure cannot be computed because of a fundamental incompleteness in the measured data. However, it is possible to compute an upper bound to such a cross-correlation. A simple example demonstrates that this information can be the basis of a technique for structure determination that can make effective use of an interactive graphics system.Model building by cross-correlations has intrinsic advantages over usual crystallographic techniques based on the autocorrelation or Patterson function, especially for large structures. This is significant, for crystallography of biological macromolecules has been and will continue to be a field of intense interest.

Computer graphics in geophysics

Abstract: It has become increasingly apparent that the large quantities of geophysical data being collected by modern instrumentation must be efficiently stored, processed, and displayed before meaningful interpretation can be undertaken. To meet these needs a man‐machine interactive computing system has been developed to provide the geophysicist with a direct communication link to the digital computer and methods for providing two‐ and three‐dimensional representations of geophysical data on cathode‐ray tubes (CRT). Gravity, magnetic, resistivity, and induced‐polarization responses have been modeled on the interactive system and displayed on a CRT. The interactive modeling processes allow the direct interchange of geophysical variables and data followed by the display of the recomputed models and corresponding theoretical responses. Model parameters can be monitored visually and continuously adjusted for a better solution. In addition, color‐shaded perspective views of three‐dimensional surfaces representing aerom...

The design of interactive graphics aids to mask layout

Abstract: Recently a number of interactive graphics aids to integrated circuit mask layout have been described. A review of the particular problems involved in implementing programs of this kind will be given with a description of hardware and software techniques available for their solution. Some features of these previously described programs will be compared and used to illustrate the range of solutions available. A program, IMP, will be described that uses some software techniques, not previously employed, to provide a capable and highly flexible mask layout facility on relatively inexpensive graphics terminals.

Increasing Capabilities in Interactive Computer Graphics Terminals

Abstract: The earliest interactive computer graphics terminals were closely coupled to their central computers and placed heavy loads upon them for resource allocation. Two marked trends in the evolution of terminals have been a reduction of central computer load and exploitation of the increasing performance/cost ratio for terminal equipment. The trends have led to graphics terminals that operate on a stand-alone basis. The history of these trends is traced and particularly illustrated by the cases of the fully interactive, refreshed CRT GRAPHIC 21 and the simply interactive, storage CRT GRAPHIC 101 terminals.

A report on the use of FORTRAN-coded EXPLOR for the teaching of computer graphics and computer art

Abstract: A FORTRAN-coded version of my EXPLOR language (for the production of images from explicit patterns, local operations and randomness) has been used to teach computer graphics and computer art to a collection of undergraduate students in art and computer science at the University of California at Santa Cruz. My conclusions are (1) that this particular language makes it possible for relatively inexperienced programmers readily to produce a wide variety of interesting designs, (2) that a rather significant scope and quality of computer graphics can be done with simply a line printer as the output device (other equipment became available during the program) and (3) that teaching of the important concepts of computing can be facilitated by the use of graphic output - i.e. graphics can be considered an effective approach to computing as well as vice versa.

Interactive computer graphics and macromolecular structures

Abstract: In 1964 on Project MAC at MIT, Levinthal and Langridge first applied interactive computer graphics to molecular model building (1, 2). Since then a number of laboratories have developed computer graphics systems to suit their particular needs (3, 4, 5, 6).I shall begin by describing the system that we have developed in the Princeton University Computer Graphics Laboratory during the past year to investigate macromolecular structures.

Increasing capabilities in interactive computer graphics terminals

Abstract: The earliest interactive computer graphics terminals were closely coupled to their central computers and placed heavy loads upon them for resource allocation. Two marked trends in the evolution of terminals have been a reduction of central computer load and exploitation of the increasing performance/cost ratio for terminal equipment. The trends have led to graphics terminals that operate on a stand-alone basis. The history of these trends is traced and particularly illustrated by the cases of the fully interactive, refreshed CRT GRAPHIC 21 and the simply interactive, storage CRT GRAPHIC 101 terminals.

Generation of interactive displays from FORTRAN using the PDP ‐ 10/LDS‐1 computer graphics system

Abstract: The PDP-10/LDS-1 combination is a powerful and versatile computer graphics system. A package of programs described here permits the generation of displays and interaction with them by means of simple calls from FORTRAN programs. This makes computer graphics available to individuals who know a little FORTRAN but no assembler language. It serves also as a useful introduction to the LDS-1 for experienced programmers who intend to learn the assembler language and to write their own programs Experience with the language has shown that it is learnable quickly by the class of users at which it is aimed. In addition, the same package has been used by more experienced programmers as a powerful research tool in the study of conformations of biological macromolecules, such as proteins, DNA and RNA.

An interactive computer graphics space allocation system

Abstract: An interactive graphics space allocation system is described with which a designer at the console of an IBM 2250 can generate and edit preliminary building layouts.