Now showing items 21-40 of 114

    • 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 ...
    • 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. ...
    • 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 ...
    • 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 ...
    • A Model for Description and Synthesis of Heterogeneous Textures 

      Englert, Gabriele; Sakas, Georgios (Eurographics Association, 1989)
      Existing texture models either describe textures as a non-hierarchical surface property (by means of Markov chains, time series and other stochastic methods) or distinguish only between micro and macro textures. Besides ...
    • Visualisation in Astrophysics 

      Ertl, T.; Geyer, F.; Herold, H.; Kraus, U.; Niemeier, R.; Nollert, H.- P.; Rebetzky, A.; Ruder, H.; Zeller, G. (Eurographics Association, 1989)
      This paper reports on progress we have made in modelling cosmic X-ray sources on supercomputers. The results we present are meant to serve as an example for the fact that sophisticated visualization techniques play a crucial ...
    • Visualisation of Digital Terrain Data 

      Thiemann, Rolf; Fischer, Joachim; Haschek, Guido; Kneidl, Gerald (Eurographics Association, 1989)
      Visualisation technology has found practical application in the field of terrain data processing. A raster data base (RDB-) concept will be introduced, i.e. a multi-dimensional concept of terrain data using elevation data, ...
    • Deformation of Solids with Trivariate B-Splines 

      Griessmair, Josef; Purgathofer, Werner (Eurographics Association, 1989)
      Solid geometric models can be deformed to free-form solids by the use of trivariate B-splines. This paper describes the problems of implementing such transformations for shaded rendering. The surfaces are subdivided into ...
    • A Parallel Image Computer with a Distributed Frame Buffer: System Architecture and Programming 

      Potmesil, Michael; McMillan, Leonard; Hoffert, Eric M.; Inman, Jennifer F.; Farah, Robert L.; Howard, Marc (Eurographics Association, 1989)
      We describe the system architecture and the programming environment of the Pixel Machine - a parallel image computer for 2D and 3D image synthesis and analysis. The architecture of the computer is based on an array of ...
    • Adding Parallelism in Object Space to the Rendering Pipeline 

      Chapman, Paul A.; Lewis, Eric (Eurographics Association, 1989)
      This paper analyses the problem of adding parallelism to the rendering pipeline and discusses the reasons for advocating an object-space partition. Consideration of the methods of work distribution and the rendering ...
    • 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 ...
    • 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, ...
    • A VLSI Chip for Ray Tracing Bicubic Patches 

      Bouatouch, Kadi; Saouter, Yannick; Candela, Jean Charles (Eurographics Association, 1989)
      This paper deals with the integration of a VLSI chip dedicated to ray tracing bicubic patches. A recursive subdivision algorithm is embedded in this chip. The recursion stops when the termination conditions are met. A ...
    • Two Object-Oriented Models to Design Graphical User Interfaces 

      Hübner, Wolfgang; Gomes, Mario Rui (Eurographics Association, 1989)
      Object-oriented concepts are well-suited to deal with the characteristics of user interfaces. Up to now several attempts to integrate the object-oriented paradigm in user interface models were evolved and led to distinctive ...
    • Components, Frameworks and GKS Input 

      Duce, D. A.; Ten Hagen, P.J.W.; Van Liere, R. (Eurographics Association, 1989)
      This paper was inspired by the Components/ Frameworks approach to a Reference Model for computer graphics, currently under discussion in the ISO computer graphics subject committee. The paper shows how a formal description ...
    • On the Software Structure of User Interface Management Systems 

      Burgstaller, Johann; Grollmann, Joachim; Kapsner, Franz (Eurographics Association, 1989)
      Specific systems for the development of user interfaces (Uls) are used today for coping with the increasing problems of human-computer communication. Some of those systems are based on well-defined models for humancomputer ...
    • 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 ...
    • Accelerated Radiosity Method for Complex Environments 

      Xu, Hau; Peng, Qun-Sheng; Liang, You-Dong (Eurographics Association, 1989)
      As form-factor calculation costs about 90% of the computing time when applying radiosity approach for realistic image synthesis, it is of great significance to reduce the required computation, An accelerated radiosity ...
    • The Structure of Tube - A Tool for Implementing Advanced User Interfaces 

      Hill, Ralph D.; Herrmann, Marc (Eurographics Association, 1989)
      Good user interfaces are very costly to implement and maintain. As user interfaces become more advanced, moving to various forms of direct manipulation, they become even more expensive and difficult to implement. In the ...
    • 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. ...