Integration of Immersive Walking to Analyse Urban Daylighting Ambiences

Abstract

The urban environment is defined as the interaction between the city's morphological characteristics and its physical behaviour based on human interpretation. Contemporary psychology emphasizes the relation between perception and action and confirms that perception can be enhanced by the receptor's motion. Basing this study on these principles, it is assumed that virtual reality techniques bring both immersion and interaction to static computer generated images and they can be used to study sunlight effects as well as daylight ambience. This paper shows the methodology of ‘sunlight effects’ analysis of both real and virtual worlds and builds a framework for a comparison.

Notes

1. The ‘Gestalt theory’ proposes to define the principal of perception, it is a movement founded by Wertheimer (1912), Köhler (1929) and Koffka (1935). It is based on a several laws of organization: Law of proximity, law of similarity, law of closure, law of good form, law of good continuation.

2. I² is an abbreviation of the key concepts of Virtual Reality: Interaction and Immersion.

3. Radiosity is a rendering method that simulates light reflecting off one surface and onto another. It is a more accurate method of rendering light and shadows than ray tracing. Radiosity produces the soft shadows from multiple reflections and light sources that exist in the real world.

4. This compromise was determined by taking into account:

The observer must be close to the screen in order to improve his field of view;

He should not be too close in to order to maintain a small perception angle of the screen pixels and to avoid a hotspot effect due to the projectors (avoided thanks to the use of a Fresnel lens screen);

The range of the localization sensors is about 1 metre.

5. On a dark street, the facades on a side of the street mask a part of the opposite facades, which produces the ‘imprint effect’ and invite the observer to modify his point of view to look for illuminated zone either to the top of the facades or towards the bottom of the street. This is called the ‘visual fight effect’.