Orientation and Wayfinding: Measuring Visibility

Abstract

In this chapter, we explain how the analytical logic of space syntax is applied for visibility analysis. In the previous chapter, the focus was on presenting all public spaces as axial sightlines. The individual axial line is a one-dimensional (1D) representation of public space and is useful for analysing the interrelationship of public spaces on a citywidescale. At the neighbourhoodscale, a two-dimensional (2D) representation of spatial elements can be useful. In particular, the public realm, such as public squares, parks, and wide streets, benefits from a 2D spatial analysis with a visual field using araster-based as well as an all-line modelling approach. In order to explain visibility analysis in space syntax, we start with the well-known 2D geographical visibility analysis ‘isovist’ as a field of vision. We build upon and explain visibility point-depthanalysisand visual graph analysis. Further, we demonstrate how the simple point-depth calculations contribute to a theory on space and urban centrality. In addition, we discuss 3D isovists. Furthermore, we also demonstrate and discuss the use of the all-lineanalysis. Finally, we expound upon agent-based modelling. Exercises are provided at the end of this chapter.