a4 - woloszyn et leduc. caractérisation du potentiel paysager par le dimensionnement spatial des...
TRANSCRIPT
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
1st intercon+nental Conference of Territorial Intelligence IT-Gatineau 2011, Oct. 12-14, 2011
Outline
Context and motivations Visual perception using isovists field The method we developed Use case and results Conclusion and outlook
Powerty/inequality measurements
Social Entropy
Environmental Entropy
Microambients economics
Economical Entropy
Income distribu7on law
Econogical weight
Socioecological weight
Socioeconomical weight
DEVELOPMENT
NEEDS
RESOURCE
Context and motivations : the socio-ecological transition trade-off
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 pedestrian's 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)
let's 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
Use case
Place Royale square
Position #1 H=0.77
Position #2 H=0.78
Position #3 H=0.86
Position #4 H=0.87
Position #5 H=0.88
Conclusion and outlook
- landscape visual space geo-topical modeling
- advanced overview of the complexity and the richness of the urban fabric
- spatial potential, allowing a pedestrian to diversify his visual landscape during his walk
Challenge is to investigate the inter-sensorial ambient-scape as a basis of a multi-sensory conception in townscape planning and design
- angular perspective variability computation
Future
Done
Acknowledgements
To: F Gonzalez Cortés (Spain) for all the developments performed on the GearScape GIS.
And to: Assistant Professor B Suner (from the National School of Architecture of Nantes city, France) for his significant help in the production of the panoramic snapshots.
References