Conversions of Relief: on the perception of depth in drawings

Of the many ways in which depth can be intimated in drawings, perspective has undoubtedly been one of the most frequently examined. But there is also an equally rich history associated with other forms of pictorial representation. Alternatives to perspective became particularly significant in the early twentieth century as artists and architects, intent on throwing off the conventions of their predecessors, looked to new ways of depicting depth. In architecture, this tendency was exemplified by Modernism’s preference for parallel projection – most notably axonometric and oblique. The use of these techniques gave architects the opportunity to convey a new and uniquely modern form of spatial expression. At once shallow and yet expansive, a key feature of these drawings was their ability to support perceptual ambiguity. This paper will consider the philosophy and science of vision, out of which these preoccupations emerged. In this context, the nineteenth-century discovery of stereopsis and the invention of the stereoscope will be used to illustrate the way in which attempts to test the limits of spatial perception led to an opening up of visual experience; and provided a definition of visual experience that could encompass the representational ambiguities later exploited by the early twentieth-century avant-garde.

A Global Review on Peri-Urban Development and Planning

Urban regions worldwide are increasingly facing the challenge of dealing with highly dynamic metropolitan growth and, at the same time, institutional changes like decentralisation and globalisation. These kinds of changes express themselves most evidently in peri-urban areas, where urban and rural life meets. These peri-urban areas in particular have been the stage for rapid physical, social and economic transformations, both in developed and developing countries. Peri-urbanization takes place here. Based on literature review, this paper presents an effort to identify generic attributes of peri-urbanisation and the way in which development planning tends to reply. Three major attributes are identified: peri-urban space (the spatial expression of peri-urban development), peri-urban life (the functional appearance of land uses, activities and peri-urban innovation), and peri-urban change (a causal and temporal perspective featuring flows and drivers of change). It is also shown that prevalent institutional replies in planning and development generally fail to acknowledge the dynamic and increasingly fragmented attributes of global peri-urbanisation.