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IEEE Computer Graphics and Applications

Issue 1 • Jan. 1990

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Displaying Results 1 - 7 of 7
  • Automatic tension adjustment for interpolatory splines

    Publication Year: 1990, Page(s):10 - 17
    Cited by:  Papers (1)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    The authors deal with anomalous oscillations often exhibited by cubic spline interpolating curves. These oscillations, which are not suggested by the data, can be treated with a shaping parameter called tension, which is introduced by generalizing the cubic spline formation in some fashion. The authors consider the associated problem of estimating the magnitude of the tensions necessary to achieve... View full abstract»

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  • Antialiasing scan-line data

    Publication Year: 1990, Page(s):18 - 30
    Cited by:  Papers (1)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1189 KB)

    The output of a scan-line visible-surface algorithm is a collection of scan-line segments with associated simple shading functions, which together define the shading as a function of a continuous variable along each scan line. A hybrid antialiasing method that uses this information fully is presented. The method extends to the case where an image transform maps the scan lines into slanted lines in... View full abstract»

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  • Visualizing functions over a sphere

    Publication Year: 1990, Page(s):32 - 40
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (819 KB)

    Techniques for the visualization of a scalar-valued function defined over a spherical domain are discussed. Functions of this type arise, for example, in the fitting of measured data on the surface of the earth. Methods for contouring and for displaying the graph of a function are presented, along with several examples. The projected graph technique can also be considered as a method for modeling ... View full abstract»

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  • Visualizing radiation patterns of antennas

    Publication Year: 1990, Page(s):41 - 49
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1002 KB)

    An efficient computer graphics tool for investigating the radiation patterns of antennas as functions of their design parameters is presented. Radiation patterns (or the magnitudes of field distributions) of antennas are treated as three-dimensional surfaces, since the magnitudes of the far-field distributions are functions of polar and azimuthal angles. Two-dimensional GKS (Graphics Kernel System... View full abstract»

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  • Bezier surface/surface intersection

    Publication Year: 1990, Page(s):50 - 58
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (697 KB)

    The computational requirements and accuracy of two methods for finding the intersection of Bezier surfaces are examined. In both methods, the existence of an intersection curve is confirmed by using the convex hull property of such surfaces. The first method evaluates the intersection by recursive subdivision of two patches with overlapping hulls. The second method detects a point on the intersect... View full abstract»

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  • Geometric continuity of parametric curves: constructions of geometrically continuous splines

    Publication Year: 1990, Page(s):60 - 68
    Cited by:  Papers (21)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (815 KB)

    Some observations are made concerning the source and nature of shape parameters. It is then described how Bezier curve segments can be stitched together with G/sup 1/ or G/sup 2/ continuity, using geometric constructions. These constructions lead to the development of geometric constructions for quadratic G/sup 1/ and cubic G/sup 2/ Beta-splines. A geometrically continuous subclass of Catmull-Rom ... View full abstract»

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  • Triage tables

    Publication Year: 1990, Page(s):70 - 75
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    The author considers the application of the principle of triage to computer graphics to speed up certain types of algorithms. He describes a very simple data structure that he has used to keep track of triage information in several situations. He applies his method to Warnock's algorithm and to a hidden-line-elimination problem.<> View full abstract»

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Aims & Scope

IEEE CG&A bridges the theory and practice of computer graphics. From specific algorithms to full system implementations, CG&A offers a unique combination of peer-reviewed feature articles and informal departments, including product announcements.

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Editor-in-Chief
L. Miguel Encarnação
University of Iowa