1st intercon+nental Conference of Territorial Intelligence IT-Gatineau 2011, Oct. 12-14, 2011 A landscape potential characterization: spatial template of pedestrian ambient fields within the urban fabric P. Woloszyn and T. Leduc ESO and CERMA Laboratories, CNRS, France
Outline Context and motivations Visual perception using isovists field The method we developed Use case and results Conclusion and outlook
Context and motivations : the socio-ecological transition trade-off Income distribu7on law Powerty/inequality measurements Economical NEEDS Social Entropy Socioeconomical weight Entropy RESOURCE DEVELOPMENT Econogical weight Socioecological weight Environmental Entropy Microambients economics
Focus on visual ambiences : isovists field The isovist is simply the Gibsonian optic array, with the wavelength and intensity information omitted, It describes local geometrical properties of spaces with respect to individual observation points and weight all the possible view directions equally. It is a 2D horizontal slice of pedestrians surrounding space; The set of all points in an environment of opaque surfaces that are visible from a given view-point; A useful tool to define the open space concept (= the empty space, the void, between the surrounding buildings).
Our proposal Combine: A sort of “surface ray casting” strategy (an angular abscissa sampling of the star-shaped isovist), With a tool from information theory (Shannon entropy), So as to produce: A sensory based Digital Terrain Model
Some more details sample the region of interest into a set of punctual positions in each of these punctual locations, determine the corresponding partial isovist convert all these isovists (2D star shaped polygons) into a set of function of radial distances (dimension reduction operation) lets assume that each function of radial distances represent a 1D random variable, and compute the corresponding Shannon entropy value represent all these entropy values into a raster color map
Function of radial distances and dimension reduction operation Nyquist–Shannon sampling theorem Shannon entropy computation
Conclusion and outlookDone- landscape visual space geo-topical modeling- angular perspective variability computation- spatial potential, allowing a pedestrian to diversify hisvisual landscape during his walk - advanced overview of the complexity and the richness of the urban fabricFutureChallenge is to investigate the inter-sensorial ambient-scape as a basis of a multi-sensory conception intownscape planning and design
AcknowledgementsTo:F Gonzalez Cortés (Spain) for all the developmentsperformed on the GearScape GIS.And to:Assistant Professor B Suner (from the National Schoolof Architecture of Nantes city, France) for his significanthelp in the production of the panoramic snapshots.