IsoVist of Street Network Comparison

What is Isovist

A single isovist is the volume of space visible from a given point in space, together with a specification of the location of that point. It is a geometric concept coined by Clifford Tandy in 1967 and further refined by the architect Michael Benedikt.

Isovist values defination page: https://isovists.org/user-guide/4-2-1-area/

Tool Introduction

The purpose of this grasshopper tool development is to facilitate urban designers and landscape designers to compare the value of isoview on the way when the road traffic reaches the green space. The tool is different from other isoview tool in that it introduced the comparison between the most calculated distance and the specific IsoView value (Area, degree of closure, elongation, etc.), so as to facilitate the designer to compare the difference between the past and the current planning or the difference between different parts of the city.

Before Start：

• Grasshopper in rhino 6/7
• Install “caribou”plugin（You can download it through rhino's package manager or food 4rhino）＆ “Decoding scape"(https://toolbox.decodingspaces.net/download-decodingspaces-toolbox/)
• Use open streetmap download data （You can download data from this website “openstreetmap.org/#map=5/38.007/-95.844”

Color and Graphic Display：

• orange：IsoView ases on human position
• Black：berlin wall (or other city barrier)
• Green: park area
• Pink: start point
• Blue: end point

Note：

• Please try to keep the OSM file size within 100mb, too large files will cause the tool to crash or the computer crashes
• After loading the file, please give the computer a few minutes to extract the OSM data
• Users can selectively turn on the isoview GPU acceleration module according to their computer configuration to increase the calculation speed

Operating Reults

-2.mp4

01.Comparison of static spatial distance between East Berlin and West Berlin

02.Comparison of dynamic Isovist between East Berlin and West Berlin（All Values）

02.Comparison of dynamic Isovist between East Berlin and West Berlin（Specific Value）

Operating Procedures

Tool Frame Work

Step 01-Data Collection

• Use Caribou to select the main and secondary roads and sidewalks in urban traffic for analysis, and then select the park in leisure as the green space to be analyzed

Step 02-Comparison Range Selection

• The points to be analyzed are selected by splitting the Berlin Wall and the analysis range is generated, and then classified according to the east and west sides

S2.mp4

Step 03-Shortest Distance Calculation

• Project the points generated by the park and the Berlin Wall to the street network to find the nearest point, and then import these data and the optimized street data into the shortest distance component to get the shortest distance to the east and west sides

S3.mp4

Step 04-IsoView Calculation

• Use IsoView in decoding space for analysis, and finally get 17 IsoView-related values of specific points on each road

S4.mp4

Ste p05-IsoView Visulization

• Use remap and gradient and loft to visualize the process of IsoView generation

S5.mp4

Step 06-HUman UI Data Visualization Production Charts

• Use Human UI to compare the data horizontally and vertically. Including single data comparison; overall data comparison; data average comparison

S6.mp4

Reference

• https://toolbox.decodingspaces.net/tutorial-2d-and-3d-isovists-for-visibility-analysis/
• https://caribou.philipbelesky.com/
• Dangschat, Jens S. "Berlin and the German Systems of Cities." Urban studies (Edinburgh, Scotland) 30.6 (1993): 1025–1051. Web.
• Friedemann Kunst. "From Rail-Oriented to Automobile-Oriented Urban Development and Back. 100 Years of Paradigm Change and Transport Policy in Berlin." TeMA (2016): 21–34. Web.
• Rod Stephens: Find shortest paths in a network C#,2015
• Allen, Stan. Points + Lines : Diagrams and Projects for the City. 1st ed. New York: Princeton Architectural Press, 1999. Print.
• Lynch, Kevin. Good City Form. Cambridge, Mass: MIT Press, 1984. Print.
• Davis, Brian. “Landscapes and Instruments.” Landscape Journal 32.2 (2013): 293–308. Web.
• Liu, M, and S Nijhuis. “The Application of Advanced Mapping Methods and Tools for Spatial-Visual Analysis in Landscape Design Practice.” Sustainability (Basel, Switzerland) 13.14 (2021): 7952–. Web.
• Aish, Robert. “First Build Your Tools.” Inside Smartgeometry. Chichester, West Sussex, United Kingdom: John Wiley & Sons Ltd, 2013. 36–49. Web.