Interactive Graphics Language Research Articles

The map geometric transformation

A geometric transformation useful for the positioning, orientation, and shape alteration of graphical objects is introduced. The form of its invocation in the language for interactive graphics (LIG) is described. The approach can easily specify complex transformations and functions effectively in combinations. Sample applications showing two styles of use and a description of the mathematics used to implement the transformation are included.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Group decision analysis and its application to combining opinions

This paper is about the graphical depiction of the set of feasible gains-in-utilities accruing to three Bayesians involved in the joint estimation of a multivatiate normal mean vector. The basic theory for this problem is sketched. Then a suitable parametrization of surface contours is developed. These contours allow the surface to be mapped and graphically displayed. This is done with the LIG language for interactive graphics. As the opinions of the three Bayesians diverge, the illustrations contained in the paper show how the initially smooth balloon shaped structure develops and ‘clicks’ through a flat spot and eventually becomes highly irregular with a central indentation. The result provides insight into the nature of disensus where explicit mathematical analysis is extremely difficult.

Geometric structural modelling: A promising basis for finite element analysis

Desirable features of a geometric language are discussed. The reasons behind the development of GPRIME, an interactive graphics language for structural modeling employing the cubic B-spline function as the single internal data representation for all curves and surfaces and the forces leading to particular implementation features are presented in conjunction with illustrating computer drawn graphic output. Future development of the GPRIME language and the ultimate goal of the effort are discussed.

Design For A High Level Graphics Language Machine

AbstractThis paper describes a design, evolved at Bell-Northern Research, for a high level computer that executes directly the statements of the interactive graphics language GRAPPLE. After a brief introduction to high order computers, interactive graphics, and GRAPPLE the discussion will centre around the structure of the machine in terms of stacks, registers, and functional elements, with a view to describing a functionally complete machine.

IMAGE

This paper addresses itself to the problems involved in programming an interactive computer graphics display. A list of graphical programming facilities considered necessary for an interactive graphic programming language is presented. An examination of several application programs, written in a variety of existing languages, revealed that many of these facilities are usually lacking.This paper presents the design of a new interactive graphics language 'IMAGE', developed specifically to satisfy the above criteria. The language places particular emphasis on providing a graphics application programmer the ability to program graphical interaction. The 'IMAGE' language utilizes the better features of several current graphic languages and combines these features with a unique interaction control structure. This OBJECT / ACTION control structure, the display picture description syntax and the hardware independent handling of input devices are the main features of the language, providing excellent graphical input response and drawing facilities. The device independent input / output structure permits the implementation of a portable language syntax, since there are no references to display hardware devices. All display references are performed through a virtual terminal. This paper contains a detailed description of the main features of the language and these features are illustrated in an example 'IMAGE' program.

Man-Computer Graphics in Preliminary Ship Design

The Naval Ship Engineering Center through its Computer Aided Ship Design and Construction Office is working toward maximum effective use of computers in the Navy's ship design process. Many batch type analyses were developed but certain naval architectural problems, such as ship hull form creation and arrangements, cannot readily be handled by the computer without human intervention. Hence, interactive graphics developments were required. The existing interactive graphics programing languages were applicable only to the hardware for which they were written. To minimize conversion problems of inevitable hardware configuration changes, a portable interactive graphics language was developed and used. The active graphics programs described herein are under continuing development and in use for hull form generation, deck and bulkhead location, and topside and internal room arrangements. In their present form, they are applicable to early stage feasibility and preliminary design. The Integrated Ship Design System (ISDS) is being developed to allow communication of all types of design programs, including interactive graphics through a common data base; so that all applicable preliminary ship design tasks can be done within the computer environment.