View-oriented three-dimensional visual analysis models for the urban environment

Abstract

This paper reports on two view-oriented visual analysis models for the urban environment that aim at capturing the three-dimensional (3D) urban reality. One of the models described focuses on coastal urban environments evaluation, where the orientation of the preferred view is evident. The visual openness is measured at different levels of the built volumes, relating mostly to the private domain, and from the street level relating to the public spaces. This model could easily be described as a view-oriented multi-level ISOVIST. The visual analysis and evaluation is applied to three selected case studies from around the world, and enables comparative evaluation and ranking. Another model presented is the 'spatial openness index' (SOI). It is a quantitative metric - expressed in terms of 3D visual spatial information: it measures the volume of free spaces potentially seen from a given point. In addition, it enables the simulation of weighted landscapes for a more realistic estimation of the view. This model can also be described as a 3D ISOVIST. It enables the ranking of alternative built-up configurations. The objective of such analysis and evaluations is to examine and characterize morphological principles of urban morphologies that are more permeable to the view for future planning and design research and practice. © 2005 Palgrave Macmillan Ltd.