Grasshopper reach analysis toolkit interactive parametric syntactic analysis

Abstract

Peponis, Bafna, and Zhang (2008) proposed three measures of street connectivity-metric reach, directional reach, and directional distance-to evaluate the potential of access to individual road segment in a street network. A Java program has already been developed at Georgia Tech as an ArcGIS plug-in for calculating the above measures. Although the Java program is suited for analysing large maps coming in GIS file formats, the editing of the input data is often done with other software packages which impedes a smooth dialog between the design exploration and the spatial analysis. We recently developed a toolkit for conducting reach analysis based on the platform of Rhino Grasshopper, allowing users not only to control the various parameters for the analysis in an interactive manner but also to integrate the reach analysis as an essential part of the design formulation process. With the wide recognition and popularity of Rhino Grasshopper for doing parametric design in the design community, this toolkit can also be taken as an analysis component which produces and feeds the result back into the generative component to help find the satisfying or even optimal design solution. This paper explains the data structures and algorithms that we implemented to carry out the various kinds of reach analysis, including details about how we tackled problems encountered in analysing some special street configurations. At the end, it introduces the basic functionalities of the toolkit with a simple example.