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Now showing 1 - 5 of 5
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    A Means to Improve the GKS-3D/PHIGS Output Pipeline Implementation
    (Eurographics Association, 1987) Herman, Ivan; Reviczky, Janos
    The output pipeline of GKS-3D/PHIGS isexamined to find some possible points where the implementation could be improved to raise efficiency while remaining strictly within the scope of the Standards. Some interesting results are presented in the paper which have led to a 25-30% improvement in speed when compared to a more conservative implementation.
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    On The Projective Invariant Representation of Conies in Computer Graphics
    (Blackwell Publishing Ltd and the Eurographics Association, 1989) Herman, Ivan
    A general formulation for conies and conic arcs for the purpose of computer graphics is given, based on principles and theorems of projective geometry. This approach allows the approximation of these curves by line segments to be postponed in the graphics output pipeline- it results in a more compact storage, faster approximation algorithms and smoother outlook of the curves.
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    2.5 Dimensional Graphics Systems
    (Eurographics Association, 1989) Herman, Ivan
    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 itself. The resulting system might be very advantageous for large application programs which have their own three dimensional facilities.
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    Modelling Clip: Some More Results
    (Blackwell Publishing Ltd and the Eurographics Association, 1990) Hubl, Josef; Herman, Ivan
    The modedling clip of the PHIGS ISO Standard is mathematically analysed. The most important result of this analysis is the fact that the projective image of a modding clip body (that is a not necessarily bounded convex body in space) is simply the union of two convex bodies. Furthermore, it will also be proved that in some cases one of these two bodies is empty. This fact makes the implementation of the modelling clip fairly straightforward and makes it also possible to use all already existing results on clipping against general convex bodies without change.
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    New Methods for Improving the GKS Fill Area Output Primitive
    (Blackwell Publishing Ltd and the Eurographics Association, 1987) Herman, Ivan; Reviczky, Janos
    The fill area primitive is one of the most powerful primitives of GKS and its derivatives (GKS-3D, PHIGS etc.). Since its specrfication is extremely general, it is important to explore new approaches to achieve higher performance in its implementation. In this paper fast algorithms are presented for special situations, which can be included, together with appropriate tests, into a complete GKS output pipeline. As a result, a speed improvement With a factor of two may be achieved in important practical cases.