方向線分の固有立体値に関する研究I
1958 年 29 巻 3 号 p. 199-206
詳細
1958 年 29 巻 3 号 p. 199-206
According to Ishii (1), the three-dimensional vision of geometrical figures, such as Necker cube, Schröder staircase and others, depends upon the presence of Y and ↑ (arrow) form-factors in drawings. It must be noted, however, that these form-factors are constituted with vertical and oblique lines. Therefore the real cause of the depth impression of the Y and ↑ figures might be the three-dimensionality inherent in each single directional line-drawing.
The purpose of the present study is to investigate what correspondence is found between the degree of slant and the apparent depth impression of a single line, and also what difference there is between monocular vision and binocular one to attain the depth impression in line-drawings.
In the first experiment, the line figures of 7 slant-degrees, 10°, 20°, ……, 70°, were observed. The results are shown in Table 1 and Fig. 1. Comparing these results with those of the former experiment with the parallelogram (2), the authors concluded that a single line gives solid impression no less than a parallelogram.
In the second experiment, the figures of the shape were used, which had the vertical lines under various conditions. The first group of figures were different from each other in the length of the vertical line. In the second group the distances between the vertical lines and the inclined ones were varied. And the third group had the vertical dot-lines which were drawn with various numbers of dots. The results, as in Figs. 2, 3 and 4, show that the role of the oblique line is important, the effect of vertical line being unimportant.
In the third experiment, as in the first experiment, the figures of oblique line alone were observed with a single eye, as well as with both eyes, to compare the two cases. The results are shown in Fig. 5 and Table 6. According to these, it is clear that binocular viewing is superior to monocular one in accuracy and easiness of the depth perception of figures. The differences, however, are not so great as was expected. The above mentioned findings suggest that the depth vision of line-drawings is not due to binocular disparity.
