Issue 4
https://diglib.eg.org:443/handle/10.2312/11
Regular Issue2024-03-28T14:46:22ZGKS Programming in a PHIGS Environment
https://diglib.eg.org:443/handle/10.2312/5469
GKS Programming in a PHIGS Environment
Arnold, David B.; Hall, Gillian; Reynolds, Graham J.
GKS is an international standard for the functional interface to 2D graphics, whilst PHIGS is currently an ISO work item for 2D and 3D graphics. In addition, PHIGS allows improved control over structuring graphics data in the system. With a new work item, the upwards compatability from GKS to PHIGS is being called into question. This paper is an attempt to give direction to these discussions by listing the implications of introducing a software layer between a GKS application program and a PHIGS environment on which this application is to be run. It is intended to highlight differences between the systems and to answer questions such as, "How compatible?", "Is it possible?", "How much does the software layer have to do?", etc.
1985-01-01T00:00:00ZAn Interpolant with Tension Defined over Triangles
https://diglib.eg.org:443/handle/10.2312/5470
An Interpolant with Tension Defined over Triangles
de Floriani, Leila; Dettori, Giuliana
A C1 interpolation scheme is described, which is defined over triangular grids. The interpolant is computed on the basis of curves with tension, which permit local control over the shape of the resulting surface.
1985-01-01T00:00:00ZMoving Picture Synthesis at Linkoping University
https://diglib.eg.org:443/handle/10.2312/5472
Moving Picture Synthesis at Linkoping University
Fahlander, Olov
We believe that in the future we will see a diverse variety of applications in the now emerging technology of real time computer animation. Such animations impose stringent computational and bandwidth demands on the underlying system. It is important to investigate carefully the methods best suited to the particular requirements of animation when motion is involved.1,2,3 In this paper we describe a system - Retina - which is now operational. We discuss the underlying concept of parameterization, which is of fundamental importance to the software design. Some timing data for this system will be given. A short description of the 3D editor, which is currently under development, is also given.
1985-01-01T00:00:00ZArbitrary Area Filling in a Fast Procedure
https://diglib.eg.org:443/handle/10.2312/5471
Arbitrary Area Filling in a Fast Procedure
Ying, Dao-Ning; Feng, Xing
A representation for area filling is described which allows shading of an area that may have both straight lines and circular arc edges and include holes within its boundaries. For efficiency an elimination algorithm which has a waiting line list and a currently active line list is adopted. For calculating intersections, a more time saving method is used. The algorithm and some practical examples are discussed. The main features of the algorithm are execution with high speed and less storage requirement. The program is written both in BASIC and FORTRAN 77 and could be executed on a microcomputer such as APPLE II, IBM-P/C etc. The sample outputs shown in this paper are generated by the APPLE II with high efficiency.
1985-01-01T00:00:00Z