Browsing EG1989 Proceedings (Technical Papers) by Issue Date

Now showing items 21-40 of 42

    • Blending Rational B-Spline Surfaces 

      Bardis, L.; Patrikalakis, N.M. (Eurographics Association, 1989)
      A method for blendin non uniform rational B-spline surface patches, either open or periodic, is developed. he blending surface is expressed in terms of an integral, bicubic B-spline patch. The blend ensures position and ...

    • Toward Realistic Formal Specifications for Non-Trivial Graphical Objects 

      Fiume, Eugene (Eurographics Association, 1989)
      Formal specification has long been advocated in programming methodology, and is becoming increasingly popular in computer graphics to characterise the semantics of components of graphics systems. Unfortunately, formal ...

    • Supporting Graphical Languages with Structure Editors 

      Szwillus, Gerd (Eurographics Association, 1989)
      Graphical editors are used in numerous application fields for purposes like specification, design, modelling, or description of structures of various kinds. These editors handle the graphical representations based on objects ...

    • Anti-Aliasing by Successive Steps with a Z-Buffer 

      Ghazanfarpour, D.; Peroche, B. (Eurographics Association, 1989)
      We present a method allowing to solve the three problems arising when a scene is displayed with the z-buffer algorithm. The proposed algorithm only requires one extra memory bit per pixel and delivers good quality images. ...

    • A Topological Map-Based Kernel for Polyhedron Modelers: Algebraic Specification and Logic Prototyping 

      Dufourd, Jean-Francois (Eurographics Association, 1989)
      This paper deals with the topology of surfaces, in the boundary representation of three dimensional objects. Orientable, not orientable, closed or open surfaces are efficiently described and handled when considered as ...

    • Hierarchical Texture Synthesis on 3-D Surfaces 

      Bennis, Chakib; Gagalowicz, Andre (Eurographics Association, 1989)
      This paper presents a new method for synthesizing hierarchical textures on 3-D surfaces. This method utilizes both a mapping technique for rendering the macroscopic structure on the surface and a generalization of the ...

    • On Reducing the Phong Shading Method 

      Claussen, Ute (Eurographics Association, 1989)
      Today, the shading method of Phong plays an important role in the design of realtime image generation systems. Often, the model has been used in combination with a color interpolation, suppressing a main property of this ...

    • The Macro-Regions: An Efficient Space Subdivision Structure for Ray Tracing 

      Devillers, Olivier (Eurographics Association, 1989)
      Ray tracing is the usual image synthesis technique which allows rendering of specular effects. The use of space subdivision for ray tracing optimization is studied. A new method of subdivision is proposed : the macro-regions. ...

    • Forest of Quadtrees: An Object Representation for 3D Graphics 

      Kaufman, Arie; Bandopadhay, Amit (Eurographics Association, 1989)
      A forest of quadtrees is proposed as an alternative data structure for representing and manipulating 3D and 2.5D graphics. A data representation of a forest offers space savings over common quadtrees by concentrating the ...

    • MICRO-UIDT: A User Interface Development Tool 

      Mao, Qijing (Eurographics Association, 1989)
      A user interlace development tool called Micro-UIDT is described. Micro-UIDT provides an interactive design environment fur the user interface designers. The designing language for defining user interfaces are visual and ...

    • An Analysis of Modeling Clip 

      O Bara, Robert M.; Abi-Ezzi, Salim (Eurographics Association, 1989)
      Modeling clip gives an application the ability to remove sections of an object in order to view internal detail. The clipping volume defied by modeling clip can be concave and disjoint, and is composed of a set of volumes ...

    • Algorithms for 2D Line Clipping 

      Skala, Vaclav (Eurographics Association, 1989)
      New algorithms for 2D line clipping against convex, non-convex windows and windows that consist of linear edges and arcs are being presented. Algorithms were derived from the Cohen-Sutherland 's and Liang-Barsky s algorithms. ...

    • Non-Planar Polygons and Photographic Components for Naturalism in Computer Graphics 

      Hofmann, Georg Rainer (Eurographics Association, 1989)
      The measuring of natural objects like landscapes and already existing (not simply planned!) buildings produces natural data. That data of hue geometry typically consists of Non-planar Polygons. These may be triangulized, ...

    • Ray Tracing Polynomial Tensor Product Surfaces 

      Giger, Christine (Eurographics Association, 1989)
      With regard to ray tracing algorithms for polynomial tensor product surfaces, the most timecritical step is to find an intersection point of a ray and a surface. In this case it proves to be very difficult to decide whether ...

    • Graph Grammars, A New Paradigm for Implementing Visual Languages 

      Goettler, Herbert (Eurographics Association, 1989)
      This paper is a report on an ongoing work which started in 1981 and is aiming at a general method which would help to considerably reduce the time necessary to develop a syntax-directed editor for any given diagram technique. ...

    • Highlight Shading: Lighting and Shading in a PHIGS+/PEX-Environment 

      Poepsel, J.; Hornung, C. (Eurographics Association, 1989)
      Todays graphics standard for the rendering of scenes with illumination and reflection is defined by PHIGS+ . PEX is a proposal to integrate that functionality into the window environment of X. This paper first describes ...

    • Representing Tolerance Information in Feature-Based Solid Modelling 

      Falcidieno, Bianca; Fossati, Bruno (Eurographics Association, 1989)
      In this paper a system for defining dimensions and tolerances is presented which deals with the geometric representation of the objects in a coherent and compact way. This model is a combination of a hierarchical boundary ...

    • 2.5 Dimensional Graphics Systems 

      Herman, Ivan (Eurographics Association, 1989)
      The outline of an extension of traditional 2D graphics systems is given. This extension is aimed at supporting a three dimensional application program, without incorporating full viewing into the general graphics system ...

    • GKS, Structures and Formal Specification 

      Duce, D. A. (Eurographics Association, 1989)
      There are now three International Standards for application program interfaces for computer graphics programming, GKS, GKS-3D and PHIGS. In this paper a simplified model GKS-like system is described and a 2D PHIGS-like ...

    • Message-Based Object-Oriented Interaction Modeling 

      Breen, David E.; Kühn, Volker (Eurographics Association, 1989)
      This paper describes a message-based object-oriented tool for exploring mathematically-based interactions which produce complex motions for computer animation. The tool has been implemented as an object in the object-oriented ...