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Volume 17 (1983)
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- Issue 1 Pages 1-
Volume 17, Issue 1
Displaying 1-6 of 6 articles from this issue
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Kazuhiko TAKEYAMA1983 Volume 17 Issue 1 Pages 1-6
Published: 1983
Released on J-STAGE: August 25, 2010
JOURNAL FREE ACCESSParallel projection is classified into orthogonal projection and oblique projection. Therefore, the orthogonal projection and oblique projection must be considered as a whole. In this paper, the author shows a general formula in which the distortion factors belonging to axonometric axes and the angles between any two axonometric axes in an oblique projection are expressed by the direction cosines of the perpendicular of the image plane and the direction cosines of the projecting line. This formula is applicable to the well-known formula in the orthogonal projection as a particular case.
Transformation of an image in parallel projections should be considered as a rotation of the image plane around one of the axes of axonometry. The author also shows a general formula of the axonometric axes which are projected onto any one of the planes holding an axis in common with the original plane. In order to clarify the distortion of an oblique projection from the orthogonal projection, the above-mentioned direction cosines, distortion factors and angles, expressed as the function of the rotation angle of the image plane, are described through the medium of the example on the isometric projection.View full abstractDownload PDF (404K) -
Eiichi Ohta, Kazuichiro Minami1983 Volume 17 Issue 1 Pages 7-10
Published: 1983
Released on J-STAGE: August 25, 2010
JOURNAL FREE ACCESSTo draw a perspective, we have to draw many straight lines passing through a vanishing point. If the vanishing point exist outside of the drawing board, it is difficult to draw them without instrument. We devised a drafter useful in such a case. This drafter has two sliding guide ways by both sides of the drawing board. A slider A moves along the right guide way. Two sliders B and C move along the left guide way. The positions of slider A and B are determined by a straight bar which turns round a fixed point inside of the drawing board. The displacements of A and B are in the opposite direction and the ratio of these is constant. The sliders B and C are connected by pulleys and a belt, so their displacements are equal in length and opposite in direction. Then, the displacements of A and C are in the same direction and the ratio of these is constant. The elongation of the straight line connecting the sliders A and C passes through a fixed point outside of the darwing board. Therefore, we can draw many straight lines passing through a vanishing point outside of the drawing board.View full abstractDownload PDF (2086K) -
Masayuki Ikeuti1983 Volume 17 Issue 1 Pages 11-16
Published: 1983
Released on J-STAGE: August 25, 2010
JOURNAL FREE ACCESSThe purpose of this note is to find an adequate conception of properties of space curve by straightedge and compass methods. The horizontal trace of the osculating plane coincides with the tangent line of the locus which is drawn by the horizontal trace of the tangent line moving along the space curve. The radius of curvature, torsion, and the osculating sphere can be found using the projection of the osculating plane. The projection of the center of the osculating sphere can also be drawn using the projection of the osculating plane.View full abstractDownload PDF (415K) -
[in Japanese]1983 Volume 17 Issue 1 Pages 17-22
Published: 1983
Released on J-STAGE: August 25, 2010
JOURNAL FREE ACCESSDownload PDF (380K) -
[in Japanese]1983 Volume 17 Issue 1 Pages 23-24
Published: 1983
Released on J-STAGE: August 25, 2010
JOURNAL FREE ACCESSDownload PDF (142K) -
[in Japanese]1983 Volume 17 Issue 1 Pages 25-32
Published: 1983
Released on J-STAGE: August 25, 2010
JOURNAL FREE ACCESSDownload PDF (484K)
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