91 The grasping hand as form generator Generative modelling in physical and digital media Maria Dimitriou, Sophia Vyzoviti Department of Architecture, University of hessaly - Greece Abstract. Grasping, which comprises one of humankind’s primitive relexes is considered as an instinctive gesture that calibrates and grasps materiality. Its’ material efects are illustrated with a case study in crumpling, a randomly folded surface condition whose complex geometry is generated dynamically by the force ingested by the human hand. he paper addresses combinatorial methodologies for form generation that employ both computational tools and material processes making evident a symbiosis between the two. Exploring generative processes for material driven free- form surface generation, the paper demonstrates computational models of crumpled surfaces and their fabrication potential. Keywords: design methodology, form generation, folding, crumpling, grasping Introduction Material driven form generation experiments have a long tradition in the architectural avant-garde. At the preparatory workshops led by Joseph Albers at the Bauhaus during the 20’s form generation was directly done with material handling, (Bergdoll & all 2009) intending to familiarize students with abstract spaces deriving from surface transformations caused by the stress and strength of paper. Since the mid 90s surface transformation morphogenetic studies in paper and other sheet materials have been exacerbated and associated with strategies of folding, surface manipulation and the creation of artificial terrains (Allen 2011). Material computing is a recent discipline specific term that describes the analogue form-finding processes complementing the new digital design tools that might in fact be described as quasi-physical form-finding processes (Schumacher 2007). Following the evolution of the notion of surface in contemporary architecture, we observe that digital design methodologies have paradoxically revamped physical modelling, in an expanded notion of material computing which not only complements but also challenges the overall form, distinct component, and texture generation. In this framework the paper addresses combinatorial methodologies for free-form surface generation that employ both computational tools and material processes outlining interdependencies between the two. Grasping, which comprises one of humankind’s primitive reflexes (Schott & Rossor, 2002) is considered in the context of this paper as an instinctive gesture that calibrates and grasps materiality. The grasping hand operates as a dynamic free-form surface generator, ingesting patterns of stress upon a sheet that affect its performance and may in retrospect provide guides for interaction with the material such as creases, bends, and twists.