A Discussion on Evaluating Indicators of the Sense of Physical Oppression and the Sense of Openness Using Imaging Experiments

Abstract

This is a study on identifying three indicators to evaluate the following senses of physical oppression and of openness in urban spaces-configuration factors, solid angles, and space quantity. These senses of physical oppression and openness were evaluated by students of architecture for images of 3DCG modeling streets in the Sangenjaya area of Tokyo�s Setagaya ward. Heights of special buildings on 3DCG modeling images are changed and fixed images toward the special buildings and moving images showing the whole a street were evaluated. The images were analyzed using the relationship between the three indicators and the senses of physical oppression and of openness influenced by changes of buildings� height. The results show that first, three indicators show high correlation for evaluating those senses of physical oppression and of openness for both fixed and moving images. Second, as the spaces evaluated expand from part to whole, the correlation of solid angle are higher than the correlation of configuration factor and the result shows that solid angles connotes the concept of space quantity. Therefore, the solid angle is suggested as the most reasonable indicator for evaluating the senses of physical oppression and of openness in urban spaces.

Measuring oppressiveness of streetscapes

“…5 presents a significant increase in oppressiveness perception when a building's solid angle increases. This finding is consistent with those of Asgarzadeh et al (2009), Byun et al (2011), Hwang (2007, and Takei and Oohara (1978). Since the solid angle is directly related to the building mass in a streetscape, the higher the building rises, the larger the solid angle becomes.…”

“…9 in comparison to Fig. 10 (R 2 = 0.508) confirms the results of the research of Byun et al (2011) and Hwang (2007) that solid angle is a better physical index in comparison to configuration factor to measure oppressiveness. However, these results contradict the findings of Takei and Oohara (1978) and Takei and Fukushima (1983) who suggested that configuration factor is a better physical index to measure the oppressiveness.…”

“…Takei's research concluded that configuration factor (see Appendix for details) is the most effective predictor for oppressiveness and suggested that ω = where ω is the perceived oppressiveness of a streetscape and is the configuration factor. More current research (Byun, Yoshizawa, Munakata, Koga, and Hirate, 2011) concluded that solid angle is the better explanation and suggested that ω = ˝ where ˝ is the solid angle of the buildings. Since configuration factor and solid angle are closely mathematically related, this research will therefore focus mainly on the solid angle.…”