Exploration of Isovist Fields to Model 3D Visibility With Building Facade

Abstract

Visibility of a space have been defined in several different ways: such as the axial line covering a convex space, a convex space defining the fattest shape in a space and an Isovist field formed by a field of vision at a given vantage point. Isovist fields are referred to as a descriptive medium to describe a movement by reviewing and analyzing geometric properties in them. Many descriptive methods for analysis of three-dimensional isovist are applied to analyzing the morphological properties in a 3D space more realistically. Although these models are regarded as a more advanced method for describing spatial properties, they have pros and cons such as complex mathematical calculations and somewhat arbitrary calibration in addition to huge consumption of memory space. These difficulties lead to the development of a three-dimensional visual accessibility model that explores the implication of building shape on the calculation of isovist fields drawn on a 2D plane. We propose a conceptual framework of how to measure the isovist field not as a 3D volume but as a combination of 2D plane on the ground with the 3D building shape of it's facade.