THE EXECUTED AND THE OBSERVED IN SKETCHES: VISUALAND COMPUTATIONAL PROCESSING FOR EXPLORATIVE DRAWINGS Onur Y. GÜN Massachusetts Institute of Technology, Cambridge, MA, United States oyucegun@mit.edu Abstract. Drawing is expressing. The mind’s eye works with the drawing to materialize ideas via transforming them into visual abstractions. The genuine supremacy of drawing emerges from its potential to evoke, not from its ability to represent. Computers are harbingers of unprecedented and enriching draw- ing environments. Yet they also introduce ambivalences because they suppress drafter’s bodily and perceptual engagement with drawings. This paper aims to delineate the similarities and differences between hand drawing and (via-com- puter) algorithmic drawing for design. The goal is to discuss the altering role of eyes and hands in long-contrasted virtual and material environments of drawing. The outlined comparisons of algorithmic and hand sketching should encourage research for blending digital and analogue modes of sketching. Keywords. Drawing; computation; sketch; algorithmic; design; studio; visual; calculation. 1. Story of “Two Squares”, Four and a Half Centuries Apart The oldest preserved architectural drawings date back to the Gothic Era. Most of the drawings are generated for representative reasons, and it is hard to determine whether they were produced prior to or after construction. These drawings are not to scale, they don’t feature shade and shadow, and a sense of depth is hardly per- ceivable. Gothic drawings highlight the vertical linearity, and are flat in nature (Branner, 1997). In some drawings buildings almost disappear under the domi- nantly drawn ornamental elements. However, a limited number of instructional set of drawings such as the ones included in Roriczer’s Booklet Concerning Pinnacle Correctitude, represent different characteristics. In the second half of the 15 th century, Mathes Roriczer (aka Matthäus Roritzer), a German master builder of cathedrals, prepared a design booklet to elaborate on what he called the “proper way of designing and building pinnacles” for Gothic R. Stouffs, P. Janssen, S. Roudavski, B. Tunçer (eds.), Open Systems: Proceedings of the 18th International Conference on Computer-Aided Architectural Design Research in Asia (CAADRIA 2013), 801–810. © 2013, The Association for Computer-Aided Architectural Design Research in Asia (CAADRIA), Hong Kong, and Center for Advanced Studies in Architecture (CASA), Department of Architecture-NUS, Singapore. 801