Pattern L-System: Visual Representation Of Pattern Language Using L-System

Junah Yu Hanyang University
Deedee Min Hanyang University

A Pattern Language (Alexander, 1977) is renowned for providing simple, conveniently formatted, humanist solutions to complex design problems ranging in scale from urban planning to interior design (Dawes, 2017). The book contains 253 design rules for how humans interact with built forms reflecting different lifestyles, customs, and behaviors, satisfying basic human needs (Salingaros, 2014). Conceptually, A Pattern Language is useful to non-professionals as the patterns are semantic and abstract. In fact, it was initially written mainly for the public to build and develop their own pattern language (King, 1993). Despite the intention, the concept has been more widely adopted by computer science professionals rather than the community members for public space design projects (Salingaros, 2014). One of the possible reasons is the lack of visualization and interaction of the patterns making it difficult to be used hands-on by non-professionals. For this research, we aim to integrate the patterns from A Pattern Language into the L-system to visualize the ‘paper architecture’ into geometric forms. Specifically, we implement ‘Pattern L-System’, which generates diagrammatic floor plans using design rules partially based on the patterns. To achieve this goal, we first made analogical comparisons of the concepts, characteristics, and grammar structure between A Pattern Language and the L-system. From this process, we observed that these two concepts have different grammatical structures; while the L-system is a parallel and recursive rewriting system, A Pattern Language is serial and has a network structure. To resolve the dilemma regarding the discrepancy of grammatical structures between two concepts, we adopted the concept of Modular L-system (Cieslak et al., 2011). Next, we defined a geometric interpreter for drawing diagrammatic floor plans using turtle graphics which consist of geometrical rules for putting shapes together. Then, we selected four patterns applicable for rules in the L-system and reinterpreted the patterns for visualization using strings of turtle graphics letters that determine the turtle’s movements for the geometric representation of walls, columns, and doors. Using the previous definitions, we implemented ‘Pattern L-System’ using Processing. From this research process, we learned that Modular L-system does open up the possibility for making A Pattern Language more hands-on and interactive through visualization and modification. By visualizing patterns into geometric forms and using the recursive functions, we expect non-architects to increase the consistency, predictability, and satisfaction toward their designs. In future research, we plan to conduct usability experiments with non-professionals to compare the design experience when using the book and the system. Alexander, C. (1977). A pattern language: towns, buildings, construction. Oxford University Press. Cieslak, M., Seleznyova, A. N., Prusinkiewicz, P., & Hanan, J. (2011). Towards aspect-oriented functional–structural plant modelling. Annals of Botany, 108(6), 1025-1041. Dawes, M. J., & Ostwald, M. J. (2017). Christopher Alexander’s A Pattern Language: analysing, mapping and classifying the critical response. City, Territory and Architecture, 4(1), 1-14. King, I. F., & Alexander, C. (1993). Christopher Alexander and contemporary architecture (No. 8). A+U Publishing Company. Salingaros, N. (2014). A theory of architecture part 1: Pattern language vs. form language. Archdaily. [Online] [Accessed 10 December 2016].

Keywords: Sdg11, Sustainable Cities And Community, Community-Led Design, Pattern Language, L-System, Diagrammatic Floor Plan, Turtle Graphics, Geometric Forms

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