EG1985 Proceedings (Technical Papers)

Permanent URI for this collection

https://diglib.eg.org/handle/10.2312/13303

Browse

Now showing 1 - 20 of 36

HUTWINDOWS: AN APPROACH TO USER INTERFACE DEVELOPMENT
(The Eurographics Association, 1985) Koivunen, Marja-Riitta; Mntyl, Martti; C.E. Vandoni
The design and implementation of good graphical user interfaces is a difficult task requiring good taste and proper tools. The HutWindows system under development at Helsinki University of Technology is intended to be an easy-to-use set of tools for implementing a graphical user interface to an application having a simple text-oriented interface. It provides a single input channel for interleaved input from a collection of non-overlapping windows, and output primitives for the display of text and graphics. All details of the user interface are effectively hidden from the application, and can be modified by the user without touching the application code.
A Three-Dimensional Shaded Display Method for Voxel-Based Representation
(The Eurographics Association, 1985) OHASHI, Toshiaki; UCHIKI, Tetsuya; TOKORO, Mario; C.E. Vandoni
In this paper, methods for displaying solid objects represented by a three-dimensional array of voxels are described. The Linear Interpolating Projection Method is proposed as a method by which such objects can be projected onto the screen in perspective. In order to shade the projected images, the Depth only Shading Method is proposed. These methods are so simple that three-dimensional perspective images with shading can be produced rapidly. This paper also describes an architecture based on these methods for generating animation interactively.
DETERMINATION OF LOCAL COORDINATE SYSTEMS FOR TEXTURE SYNTHESIS ON 3-D SURFACES
(The Eurographics Association, 1985) MA, SONG DE; GAGALOWICZ, ANDRE; C.E. Vandoni
We propose and compare three types of local coordinate systems and describe their geometric properties Several results of texture synthesis on 3-D surfaces using these local coordinate systems are presented The synthesis procedure is driven by a texture model including only a small amount of statistical parameters
FRACTIONAL BROWNIAN RELIEF : AN EXACT LOCAL METHOD
(The Eurographics Association, 1985) FELLOUS, A.; GRANARA, J.; HOURCADE, J. C.; Vandoni, C. E.
Fractional Brownian process has been widely used for computer rendering of terrain models. The implementation constraints in Computer Graphics have led to the use of recursive methods, based on some local properties of this model. We present in this article s mathematical study of these local properties and propose a local model for fractal modeling based on strict observance of fractional Brownian probability law.
MODEL DRIVEN SYNTHESIS OF NATURAL TEXTURES FOR 3-D SCENES
(The Eurographics Association, 1985) GAGALOWICZ, ANDRE; MA, SONG DE; C.E. Vandoni
This paper presents a new method for the synthesis of textures on 3-D surfaces. With the exception of fractals, graftals and particle systems used for very restricted types of textures, one basic technique for the faithful reproduction of textures has been presented in the literature up to now. In this standard method, textures are synthesized by mapping a rectangular template onto a patch of the curved surface. In the method proposed here, the synthesis is achieved continuously on the surface by interpolating only statistics of the texture which have a much narrower spectrum than the texture itself so that there are no aliasing effects. A vast class of textures can be reproduced with a visual appearance similar to the reference texture used. The method applies for any 3-D surface and is relatively quick and easy.
VIEWING SOLID MODELS BY BINTREE CONVERSION
(The Eurographics Association, 1985) Koistinen, Petri; Tamminen, Markku; Samet, Hanan; C.E. Vandoni
A hidden surface algorithm is presented for viewing constructive solid geometry representations of solids (CSG trees) by converting them implicitly into a 3-d recursive spatial subdivision (bintree). The algorithm prunes the CSG tree to its minimal representation within each bintree block and does not evaluate it in regions of space (bintree nodes) that are totally hidden to the observer.
GRAPHICS PROGRAMMING FOR KNOWLEDGE-GUIDED INTERACTION
(The Eurographics Association, 1985) Tibbert, Lee; Bergeron, R. Daniel; C.E. Vandoni
This paper describes a design approach that combines knowledge engineering techniques with an interactive graphics program. A prototype for specifying computer systems interactively is used to demonstrate the design approach. The program incorporates a rule-based knowledge engineering module which allows for both data base consistency and the ability to guide the user through an interactive dialogue.
PIPELINE APPROACH FOR BUILDING THE PRESENTATION GRAPHICS SYSTEMS
(The Eurographics Association, 1985) Klimenko, S.V.; Kochin, V.N.; Samarin, A.V.; C.E. Vandoni
A pipeline approach is suggested for building up presentation graphics systems from modules performing elementary transformations of graphics objects. Different ways of composing pipelines are discussed which allow the minimal system configuration and the best use of graphics hardware capabilities. It is shown that the pipeline model of a virtual graphics device yields drivers, minimal in size and simple to implementation.
Colour Section
(The Eurographics Association, 1985) -; C.E. Vandoni
Colour Section
THE USE OF GRAPHICAL SYMBOLIC COMMANDS (ICONS) IN APPLICATION PROGRAMS
(The Eurographics Association, 1985) Woodgate, H. Sam; C.E. Vandoni
This paper describes the use of Graphical Symbols (Icons) as a means of communicating operating commands between application program and users. detailed in the paper is the operational command system for a "Spread Sheet Calculator" which was &signed to be driven entirely by Graphical Symbols using a "point and activate" command method. 83 Graphical Symbols were required to operate the program and these were developed using a "graphical symbol generator". The example User experiences are also discussed.
MULTI-DIMENSIONAL GRAPHICS
(The Eurographics Association, 1985) Inselberg, Alfred; C.E. Vandoni
AN IMPROVEMENT OF THE RAY-TRACING ALGORITHM
(The Eurographics Association, 1985) COQUILLART, Sabine; C.E. Vandoni
This paper describes an improvement of the ray-tracing algorithm. The new method takes advantage of a data structure which allows us to consider only the closest objects to the path of the ray. This technique can be applied to primary and secondary rays. Using this method, the run-time depends more on the complexity of the generated picture than on the complexity of the scene.
An illumination model for ray-tracing
(The Eurographics Association, 1985) MONTCEL, Bruno TEZENAS DU; NICOLAS, Alain; C.E. Vandoni
PIPEMATIC: A DISTRIBUTED SYSTEM FOR THE DESIGN OF GEOMETRICALLY TIGHT PIPING STRUCTURES
(The Eurographics Association, 1985) Sulonen, Reijo; Tikkanen, Matti; C.E. Vandoni
The main principles of an interactive design system intended for the solution of 3D geometric placement problems are described. The first applications for the system will be related to the design of machine rooms in ships where a large number of geometric objects must be placed and connected together with appropriate piping structures. However, the system is application independent. The emphasis of this paper is on the systems structure, algorithmic problems are not dealt with. Implementation of the system is currently underway.
GEOMETRIC MODELLING USING EXACT OCTREE REPRESENTATION OF POLYHEDRAL OBJECTS
(The Eurographics Association, 1985) Brunet, Pere; Navazo, Isabel; C.E. Vandoni
In the last few years, octrees have been proposed for the representation of solids in Geometric Modelling systems. Using them, boolean operations are simple; however, they use a great amount of memory and it is very difficult to obtain smooth graphical outputs from them or to recompute the boundary model. In the present paper, a new class of Octtrees is introduced, which allows face, edge and vertex nodes as well as the classical white, black and grey nodes. The required amount of storage is less than in the case of classical Octtrees, and boolean operations are also simple. Futhermore, there exists an algorithm for the exact recomputation of the boundary model.
Graphics Programming with "Archetypes" - A Preliminary Study -
(The Eurographics Association, 1985) Martins, Fernando Mar io; Oliveira, Jose Nuno; C.E. Vandoni
This paper is a brief report on the initial phase of the formal development of a graphics programming system. At this stage of the specification, the system architecture is just outlined and attention is focussed on the conceptual level. The abstract notion of a graphic 'archetype' is introduced and proposed as a basis for the style of graphics programming to be implemented. The formal description of this meta-concept of the system is sketched.
AN INTERACTIVE RENDERING TECHNIQUE FOR 3-D SHAPES
(The Eurographics Association, 1985) KONDO, Kunio; KIMURA, Fumihiko; TAJIMA, Taro; C.E. Vandoni
This paper describes an interactive rendering technique for giving an impression of 3-D shapes. The following points are discussed : 1) The classification of continuous tone patterns 2) Methods of drawing pictures to enhance 3-D shapes 3) Rules of rendering for the representation of 3-D shapes. The following results are obtained: The use of the rendering rules and CARP facilitates the clear representation of these characteristics and is proved to be effective in creating a picture in which the shapes of bodies are clearly defined,
GKS Inquiry Functions within Prolog
(The Eurographics Association, 1985) Sykes, Pete; Krishnamurti, Ramesh; C.E. Vandoni
This paper discusses the semantics of the GKS inquiry functions within a Prolog environment and illustrates the flexibility built into a proposed Prolog binding.
CREATING CSG MODELLED PICTURES FOR RAY-CASTING DISPLAY
(The Eurographics Association, 1985) CORDONNIER, E.; BOUVILLE, C.; DUBOIS, J.L.; MARCHAL, I.; C.E. Vandoni
30-picture synthesis systems used for instance in the audiovisual field or networked services require the implementation of easy-to-use aids to composition. This particular composition software realizes the sizing and locating of even complex CSG objects in a simple and direct manner. The Ray-casting method is used for display and designation.
BICEPS - THE INTERACTIVE GRAPHICS AIDED SYSTEM FOR BI-DIMENSIONAL GEOMETRY YODELING, NESTING AND FLAME CUTTING TECHNOLOGY
(The Eurographics Association, 1985) Kobvlinski, Wiktor J.; C.E. Vandoni
An essential condition for effective usage of numerically controlled devices is their correct and efficient programming. Especially in cutting applications every nesting layout requires a new control program tape. The BICEPS system referred here has been implemented in work shops with both: batch production - very stable one and simple part cutting in repair shops where every day new parts are manufactured. In both cases significant material savings (by narrow nesting) and reduction of production preparation time are obtained. The present paper deals with the very first step of production preparation process: modeling of the geometry of Bi-dimensional (2D) contours of Darts manufactured.

Browse

Browsing EG1985 Proceedings (Technical Papers) by Issue Date

Results Per Page

Sort Options