On-photo Restitution and Management of an Angular Size-Illusion's Behaviour Experienced in Architectural/Urban Spaces

Abstract

An angular size-illusion refers to a contradictory effect related to a seeming size-decrease of focused objects as the observer approaches them. This paper continues the research in this field, trying to establish fundamental principles of how to: (a) efficiently perform an on-photo restitution of an illusion's behaviour (expressed by illusion descriptors) when it is experienced in architectural/urban spaces during movement under the influence of available triggers (represented by illusion determinants of physical nature), and (b) manage it computationally so as to be sustainable for contemporary professional practice. To explain that conceptually, one simple architectural/urban matrix is chosen and digitally photographed. Images are photogrammetrically processed and determinants-related data obtained. Subsequently, descriptors-related outputs are calculated by applying derived mathematical equations (expressed in function of those determinants-related data). Then, behaviour-charts are created and corresponding illusion-characteristics read-off. Finally, it is illustrated how to manage (intentionally modify) the restituted behaviour by varying values of acquired determinants-related data. Given results allow also to "design a new illusion" (to programme and control it) by simulating in digital VR/AR environments. Thus, any cause of unwanted/unpredictable visual impression degradations of important architectural/urban structures can be prevented or minimized (by planning and performing adequate spatial/physical interventions on existing/reconstructed/newly designed matrices).