Dynamic Perception of Transparency in Architecture: Mechanisms of the Proper Recognition of Light Permeable Surfaces

Abstract

This paper examines the issue of transparency recognition in architecture from a dynamically changing point of view. A simple and intuitive pictorial model of the transparent surface appearance is presented, followed by a discussion of the transparency processing (mid-or high-level). Two zones of perception that determine the proper perception of light-permeable surfaces are distinguished, each with their own phenomena responsible for the formation of transparency perception cues (transmittance/absorbance or reflectance). The main visual processing mechanisms are discussed, and some parallels to machine vision are found. Finally, a short checklist is presented to provide practical advice for architects dealing with large surfaces of glass in their projects.Contemporary architectural transparency seems to go beyond all previously formulated definitions. It involves new materials and technologies, as well as new ways to assess the visual perception of architecture. With the introduction of the study of the dynamic perception of architecture, previously neglected qualities of transparent materials (e.g., reflectance and refraction) have become important factors in the perception of space, and these factors are processed on different levels in the recognition of transparent materials. The approach presented here stems from architecture-based experience, but is approached from the perspective of optics and vision science. The general principles are illustrated via diagrams and individual case studies.It must be noted that the issue known as motion transparency, where "two overlapping surfaces move transparently over each other" (Snowden & Verstraten, 1999, p. 369), in other sources defined as "perception of more than one velocity field" (Qian, Andersen, & Adelson, 1994, p. 7357) is beyond the scope of this paper (Stoner, Albright, & Ramachandran, 1990). Optics of TransparencyTransparent materials are perceived differently than opaque materials. In the case of opaque objects, the phenomenon of occlusion occurs: "visible contours of the more distant object terminate at the outer boundary of the nearer one" (Wilson & Keil, 1999, p. 844). Panes-large flat thin surfaces-of transparent materials are usually so smooth that the luminous fluxes that strike them are partially reflected, partially transmitted, and partially absorbed (absorption/transmission are linked). Each transparent object absorbs part of the luminous flux energy, but simultaneously also generates specular reflections upon its surface. The optical model that approaches transparency from the position of reflected vs transmitted luminous flux balance (meaning: real and virtual images con-fused) seems to be sufficient and appropriate in consideration of optical cues distinctive for the visual system in the kinetic perception of transparency. A real/virtual image model is adopted for the sake of simplicity, as-due to the scale of the pane in architecture-other phenomena like "total internal reflection, and wavelength related effects (chromatic aberrations) cau...

There or not there? A multidisciplinary review and research agenda on the impact of transparent barriers on human perception, action, and social behavior

“…Such correspondence is not uncommon in architectural settings in which large glass panels fill a person’s entire field of view. Under such conditions, visual information about the transparent structures’ borders and edges remain inaccessible, making their detection particularly difficult ( Brzezicki, 2014 ). Unsurprisingly, undetected transparent barriers can pose a serious health and safety risk.…”

“…Although the use of transparent structures in architecture is nowadays expected to be accompanied by a careful assessment of their visibility from different viewpoints and under different lighting conditions (daytime, nighttime, backlighting; Brzezicki, 2014 ), several important questions regarding the topic remain unanswered. For instance, rather than reflecting an inborn talent, the ability to perceive transparency seems to be actively acquired during the first months of one’s life ( Johnson and Aslin, 2000 ).…”

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“…A recent trend in modern architecture is to provide maximum transparency to the building interior by reducing visual obstructions of the structural frame and envelope [1]. This movement includes the increased use of self-supporting glass structural elements and large glass panels for the façade of the buildings.…”