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Parameteris a common term used to identify a characteristic, a feature, or a measurable factor that can help in defining a particular system.1 In mathematics functions, a parametric equation defines the relation of parameters and variables. For instance, the following shows a simple math equation that defines a line with X and Y values. In this equation, X is a variable, while A and B are two parameters.
Y = AX + B
1.1 PARAMETRIC DESIGN IN ARCHITECTURE
Parametric design in architecture is a design approach that generates geometric solutions based on a family of related parameters. It emphasizes on the geometric relations between parameters and forms and uses variables and algorithms to quantify such geometric relations. For instance, designers can use 3-D software and apply parametric design methods to generate division pointson a surface. Once the points have been defined, the surface is populated with a set of connecting triangles that have no overlap. This process leaves a triangulated surface determined by the number of division points. In architectural design, each triangle can be used to design a fat panel. A paneling system can thus be created and controlled through a few parameters, such as the number of divisions. The paneling system can possess a higher level of complexity by introducing new variables into the equation such as the size of openings to create perforated panels.
Parametric design software provides architects with a series of tools to evaluate ideas in the early design phase. One of the design challenges when designing with digital models is how to evaluate the relation between a form and its performance. For instance, the geometric shape of a sunshade will affect how it casts shadows and blocks sun light. When a digital sunshade model is constructed with a set of parameters, these parameters can be modified to design the sunshade to achieve certain performance. There is an emerging design method to analyze various performance-related parameters and optimize them according to predefined rules. Designers can use parametrically controlled variables to produce alternative solutions for comparison. This approach completely transforms the design process and allows for performance-driven design and simulation to be integrated into the design process.
Parametric design also extends the digital practice into the materialization and fabrication field. Through parametric methods, highly complex architectural forms can be digitally constructed and controlled by a set of parameters. Designers can parametrically modify the digital model and prepare it for fabrication, while simultaneously evaluating its performance based on environmental, structural, or other design constraints. The parametric method revitalizes the design worldâs interest in iterations because it offers greater variations through a set of controlled mathematical parameters. This file-to-factory process enables the information flow from representational format directly to the drawings for fabrication and construction.
1.2 COMPUTATIONAL AND NONLINEAR THINKING
This book describes various methods of using parametric techniques associated with architecture design. With a set of parameters and a series of operations, a parametric model provides opportunities for designers to revisit early design decisions or generate design alternatives without redoing all the subsequence operations. Parametrically negotiable solutions can be improved through this nonlinear procedure and can achieve diversity and complexity in form generation. It is the integration of the qualitative evaluation from human brain and the powerful computation capacity of software that offers greater potentials in the exploration of innovative design solutions. By using the nonlinear design pipeline, iterations are explored by defining a network of operation nodes and variables.
âThe outcome of parametric design procedure surpasses traditional views of an optimized single solution that travels down a linear pipelineâarchitect, engineer, contractor, and fabricatorâ to seek approval from various design professionals. The computation approach offers a non-linear process that contains parameters that perform actions based on the quantifiable relation in an open-end design loop.â2
Geno Roof. In this roof modeling experiment, a prototype matrix was created to drive the deformation of a target geometry mesh. A large quantity of children roof surfaces was produced from each pair of roof parents. The first child was identical to parent A, while the last child was identical to parent B. Other children were the mixture of parent A and B with different weight combinations.
The gap between digital and physical realms is narrowing with the rapid development of digital fabrication technologies such as computer numerically controlled (CNC) mills, laser cutters, 3-D printers, and others. Designers can integrate various parameters, such as material property, tolerance, deformation, and cutting time, into the parametric equations and examinethe cost, structure, responsive performance, as well as other related information in digital format. This nonlinear procedure works as an interactive learning tool for construction prototyping and serves as an efficient way to transfer the end result of digital forms into full-scale manufactured parts.
1.3 PERFORMANCE BASED DESIGN (PBD)
Computation and nonlinear thinking promote performance-based design (PBD). âPowerful parametric tools provide both geometric modeling and analysis functions within a procedurally controlled network. The performance data, such as heat gain, stress, and solar radiation, can be easily quantified and defined to interact with other parameters.â3 Oxman describes it as design informed by internal evaluation. âPerformance driven design is a process to create a system of parameters which can be verified, validated and evaluated with facts. Supported by the modeling and simulations, Performance Based Design (PBD) uses evidence and data as the essential design driver, rather than architectâs intuition.â4 In nonlinear computation, the performance simulation is no longer simply a way to evaluate the final form,...
