Volume 05 (1986)
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Item 5th EUROGRAPHICS UK Conference: University of East Anglia, Norwich: 13-15 April 1987(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item Algorithms for Handling the Fill Area Primitive of GKS(Blackwell Publishing Ltd and the Eurographics Association, 1986) Shinde, Yogesh N.; Mudur, S.P.The fill area primitive of GKS (Graphical Kernel System)1 is one of the more powerful features which differentiates it from earlier device independent graphics software and systems. Its specification is extremely general in the form of a closed boundary, possibly self-intersecting, and whose interior can be filled in a variety of styles. However a complete implementation of this primitive is very complex. It is difficult to find a single graphics workstation incorporating this primitive in hardware or firmware. Most GKS implementations will have to include software for simulating the appearance of this primitive on the commonly available displays and hard-copy graphics devices. Correct and efficient algorithms are necessary for developing this software. Because of the generality many of the existing algorithms are not directly applicable. In this paper we describe:1. a new algorithm for clipping a fill area polygon, using what we have named as the Bridge Technique.2. implementation of a plane sweep algorithm, by Nievergelt and Preparata,2 for solid filling and hatching, particularly applicable to vector devices.3. extension of the plane sweep algorithm for filling with any given pattern on raster as well as vector devices.The algorithms have been designed to work for all special cases as well. In fact they have been implemented having in mind the fill area set primitive of GKS-3D extension.3 All these algorithms have been very successfully implemented in a commercially available GKS implementation, namely indoGKS.Item Anti-Aliasing of Computer-Generated Images: A Picture Independent Approach(Blackwell Publishing Ltd and the Eurographics Association, 1986) Chryssafis, A.A scheme is described which blurs the jagged edges of a binary picture, when it is shown on a raster display possessing a gray scale.A jagged edge is hereby defined as a one pixel discontinuity, which would result from the rounding error of vector to raster conversion.Item Artificial Intelligence in Three-Dimensional Computer Animation(Blackwell Publishing Ltd and the Eurographics Association, 1986) Thalmann, D.; Magnenat-Thalmann, N.Recent developments in hardware and software have led to the production of complex computer-generated images and films. Sophisticated algorithms like ray-tracing, fractals or particle systems allow the generation of very realistic natural scenes. However, the design of images and films is still a painful task for designers, because of the inadequacy of person-machine interfaces. A large number of parameters is necessary to build objects (curves, surfaces) to define their properties (orientation, size, colour, transparency, texture, reflectance), to specify the viewing angle, to control the lights and shadows, to define and synchronize motions.The technology of artificial intelligence and more specially knowledge engineering makes possible the development of intelligent human-machine interfaces for image synthesis and animation. Designers may communicate with design and animation systems using natural language. Basic geometric rules may be given to the computer, making it an expert in 3D geometric modeling. Languages based on the concept of frame simplify the intelligent description of complex objects. Expert systems allow the designer to specify the conditions of an image using goal-directed specifications for cameras and lights. Scripts and actors are particularly appropriate for the description of motions- the impact of these concepts on 3D computer animation is considerable. Finally, the complex problem of animation of articulated bodies may be solved using knowledge-based animation. Examples are presented using our new language EXPERTMIRA. This language is based on MIRA and PROLOG and incorporates concepts of artificial intelligence, image synthesis and animation.Item The Association for Computing in Art and Design Education (ACADE)(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item Ausgraph -86(Blackwell Publishing Ltd and the Eurographics Association, 1986) Hopgood, F.R.A.; Duce, D.A.Item Beyond Hershey: A Representation of Fonts for Computer Graphics(Blackwell Publishing Ltd and the Eurographics Association, 1986) Gossling, T.H.Hershey-s "Repertory of Occidental Fonts" is well known in the field of computer graphics, as a set of character-forms which is superior to the cruder representations used when space was at a premium. This paper gives a method of extending Hershey-s format to include true curves, thus giving near typographical quality.Item Biom orphs: Computer Displays of Biological Forms Generated from Mathematical Feedback Loops(Blackwell Publishing Ltd and the Eurographics Association, 1986) Pickover, C.A.A computer graphics algorithm is used to create complicated forms resembling invertebrate organisms. These natural morphologies are generated through the iteration of mathematical transformations. Several illustrations are chosen as examples of the diversity of biological structures which result from this technique.Item Book Reviews(Blackwell Publishing Ltd and the Eurographics Association, 1986)Book reviewed in this article:1. COMPUTER GRAPHICS - A Programming Approach2. Computer Graphics3. User Interface Management SystemsItem Calendar of Events(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item Calendar of Events(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item Calendar of Events(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item Calendar of Events 1987(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item Call for Contributions(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item CALL FOR PAPERS(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item Computer Graphics and CAD Literature A Keyword-Indexed Bibliography(Blackwell Publishing Ltd and the Eurographics Association, 1986) Owen, JonItem Displaying Relevant Features of Protein Molecules(Blackwell Publishing Ltd and the Eurographics Association, 1986) Poet, Ron; Milner-White, E. JamesWe present a novel type of computer generated picture in which the positions of the main chain alpha carbon atoms are averaged and the different types of hydrogen bonds between main chain atoms are represented by lines of different colours and thicknesses joining the alpha-carbon atoms. This allows various types of helices, beta-sheets, beta-bulges and turns to be visualized. One beta-hairpin turn exhibits a structural feature at the loop end that has previously been described as a G1 beta-bulge. It occurs in another protein by itself, and can thus be said to be a new sort of turn.Item EDITORIAL(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item EDITORIAL(Blackwell Publishing Ltd and the Eurographics Association, 1986)Item EDITORIAL(Blackwell Publishing Ltd and the Eurographics Association, 1986) Arnold, David; Enderle, Guenter