Complex Systems

Implementing Cellular Automata for Dynamically Shading a Building Facade Download PDF

Machi Zawidzki
Department of Architecture and Engineering
Ritsumeikan University
Noji-Higashi 1-1-1, Kusatsu, Japan


We present a practical cellular automaton (CA) implementation from the field of architecture that drives the modular shading system of a building facade. Some CAs produce patterns that seem to live their own life and may therefore please the human eye. Probably the most important quality of a good design is integrity of elements. By nature, a CA is an essence of integration, where all elements are interconnected and locally related to each other. Due to the computational irreducibility of CAs [1], controlling them to perform purposeful actions [2] is often challenging. Nevertheless, visual effects in the patterns created often develop intriguing complexity that is difficult to achieve by means of artistic will, whim, or chance. The four classes of CA behavior are presented with conjunction to the problem of average grayness of a pattern. Two CA classes are analyzed for potential practical use: 2-color, 1-dimension, range-1 (2C-1D-R1) and 2-color, 1-dimension, range-2 (2C-1D-R2). One problem discussed is the linear gradual change of average grayness as a function of the sequence of initial conditions. Another problem discussed is choosing a sequence of initial conditions to cause a desired change in the opacity of the shading array. A proposed realization includes a mechanical scheme that could be made inexpensively by using coupled polarized film. A rotation of one polarized film by 90 degrees causes a change in the element's transparency.