The syntactic structure of the isovist: Thresholds, depth, and distributedness

A new way of analysing the individual isovist is proposed. We show how to identify ‘thresholds’ which divide the isovist into an inner area and multiple outer areas, sometimes visible in successive layers of visual depth and sometimes extending in different directions. Thus, the ideas of depth and distributedness, fundamental to the descriptive theory of space syntax, are brough to bear on the spatial structure of the individual isovist. Furthermore, the idea of ‘thresholds’ suggests new ways of partitioning space. The paper concludes that egocentric and allocentric, subjective and objective, descriptions of environment can be systematically linked as our descriptive theories are refined.