Journal of Graphic Science of Japan
Online ISSN : 1884-6106
Print ISSN : 0387-5512
ISSN-L : 0387-5512
Volume 24, Issue 1
Displaying 1-9 of 9 articles from this issue
  • Nobuyasu ISHII, Kunio KONDO
    1990 Volume 24 Issue 1 Pages 1-8
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    In this paper we imtroduce a new display method to from a real time three-dimensional graphics using functions of ‘sprite’ and ‘raster interruption’ for high-speed movement and high-speed transformation respectively. The display method is a quasi-display method, which substitute basic solid figures for any solid figure and display them by sprites. It was realized by dynamic sorting for sprites. To display a complex solid figure, it is necessary to transform basic solid figures. The transformation was performed by the raster interruption and movement of each sprite.
    The method proposed here is found to be feasible for low-level computers e.g. a personal computer, and it is more realistic than wire-frame display methods. Moreover, those are showing the possibility of realization of the real time three-dimentional graphics.
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  • Hirotaka EBISUI
    1990 Volume 24 Issue 1 Pages 9-14
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    In this paper we present three matters. First we show that the cross sections of two circular cones, which are the spatial curve of the ovals of Descartes, can be defined by three dimensional parametric formula. These formula were derived so that we can easily obtain the perspective drawings of the spatial curve with computer graphics. Secondly, we present that the ovals can be defined by orthopoles that satisfy some conditions. This defintion indicates the geometrical composition of the ovals, and we present its proof. Finally, we describe the method to draw the normal line of the ovals and also give its proof. Thus additional new properties on the ovals are shown.
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  • —1. A Method of Three-dimensional Measurement—
    Emiko TSUTSUMI
    1990 Volume 24 Issue 1 Pages 15-20
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    The shape of the segmental living subjects, viz. right side half trunks of 28 female were measured three-dimensionally using a moiré camera and a mirror unit, and described with aid of geometrical modeling. The surface of the trunk was marked with netted measurement points which covered any anatomical landmarks so as to retain anthropometrical meanings in the following shape analysis. These points also included peak of concavity and convexity on the surface. The whole trunk surface of the marked subjects was measured with moire contours and the coordinates of the netted points were interpolated from the discrete value on the contours. For the description and shape analysis of the trunk, a geometrical model was generated putting measurement points as control points for Bézier paches. The results showed that the geometrical model approximated appropriate aspects of the original shape of the subject.
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  • Kenjiro SUZUKI, Sakiko WAKITA, Saburo NAGANO
    1990 Volume 24 Issue 1 Pages 21-28
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    It is widely believed that one of the main purposes of an early under graduate graphics curriculum is to improve the student's ability to visualize and solve spatial problems (hereafter we call this ability as VSSP ability) . There are, however, few studies on the evaluation of the im-provement of the student's VSSP ability through the curriculum. Therefore, it is not exactly clear whether the educational purpose is well accomplished or not. In order to resolve this question and to improve on the curriculum, it is necessary to develop methods of measuring the VSSP ability and to make pre and post test to the curriculum. As an attempt to gain some insight into these problems, we gave intuitive tests to the students before and after the descriptive geometry course. In the intuitive tests, the students are asked to determine the true cutting views after being given pictorial views of objects and cutting planes. The scores of the pre and post intuitive tests, together with the scores of the term-end test on descriptive geometry, were statistically analyzed. The analysis shows that the student's VSSP ability was improved through the education of descriptive geometry.
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  • [in Japanese]
    1990 Volume 24 Issue 1 Pages 29-32
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    Download PDF (229K)
  • [in Japanese]
    1990 Volume 24 Issue 1 Pages 33-36,42
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    Download PDF (731K)
  • [in Japanese]
    1990 Volume 24 Issue 1 Pages 37-42
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    Download PDF (865K)
  • [in Japanese]
    1990 Volume 24 Issue 1 Pages 43-47
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
    Download PDF (736K)
  • [in Japanese]
    1990 Volume 24 Issue 1 Pages 49-53
    Published: 1990
    Released on J-STAGE: August 25, 2010
    JOURNAL FREE ACCESS
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