Actualizing Ornament with Shape Grammars

by Magdalena Pantazi

In the past two decades, a shift in perception of the notion of ornament has occurred in architecture. Ornament, which was almost exiled from design for about a century, reappeared in architectural discourse and began to participate actively in the design process. The development of computer software seems to have had a significant impact on this shift: the use of new digital means in the design process introduced novel ways of approaching ornament design problems and, more specifically, renewed the architect’s interest in using algorithms to solve these problems. The use of algorithmic processes is expected to expand the potentialities of ornament design, leading to unique and novel artifacts. So far, however, little research has been done in this field and the reasons that led to the resurfacing of ornament in architectural design remain vague. This paper will examine the reappearance of ornament in architectural discourse and will argue that the emergence of computation facilitated this return. In order to examine how computation influenced the design of ornament I will study the way that shape grammars – a visually based computational design technique – introduce ornament into design. In this framework, I will attempt to develop a grammar for ornament design. In order to study the possible combination of the rules application and to produce many different results I will use the computer-based programming language processing.

Introduction

The current architectural building production reveals the reappearance and active participation of ornament in the design process. This is in fact the result of a shift in the perception of the notion and function of ornament that has occurred in architecture over the past two decades. Toyo Ito’s Serpentine Pavilion in London and Herzog and de Meuron’s Library in Eberswalde, Germany, as well as the Prada store in Tokyo are only a few examples that demonstrate this change in the perception of ornament. In these works ornament is no longer just a piece of sculpture, but rather a piece of textile, a piece of structure, a piece of surface or a piece of image adjusted to the building’s surface. In this new context, architects experiment with ornament in an attempt to construct new aesthetic effects. In the Prada store, a diagrid with carefully selected concave glass panels gives a quilted effect to its exterior, while in the Eberswalde Library the repetition of images on the building surfaces creates a serial effect. The Serpentine Pavilion project creates a differentiation effect by combining ornament with structure in a construction “based on an algorithm that produces an irregular pattern that is then cropped.”1 As opposed to what was the case several years ago, ornament is used today as an element that underlies certain characteristics of the building and attempts to improve the architectural results.

Until now, however, little attention has been paid to the reasons that led to the reappearance of ornament in architectural discourse. In this paper, I will argue that the emergence of computation facilitated the return of ornament in architectural design.

Ornament is defined as “a thing used to adorn something but usually having no practical purpose.”2 This definition best illustrates the general perception of ornament in architecture: decoration elements added to an existing structure. During the course of the last two centuries architects used ornament as an additional embellishment layer in the overall structure of the building. The role of the Modernist movement along with its aesthetic premises of clarity, simplicity and hygiene was especially influential in this direction.

The status of ornament in architecture, however, was different before the eighteenth century. The Italian architects Vitruvius and Alberti considered ornament to be an essential part of the building that revealed the “creativity and the beauty of the cosmic order.”3 Furthermore, the possible ways through which ornament was related to buildings, for example the various transformations and applications of shapes that resulted in different architectural products, expressed the potential ways that a building could be realized. Antoine Picon’s view on the work of ornament in architecture sheds some light on the way ornament has participated in the architectural compositions and on the way it contributes to the creation of potential architectural results. He defines ornament as a “virtual dimension of work in architecture.”4

It is this characteristic of ornament, its “virtual dimension,” that brought ornament back to the center of current architectural discourse. The interest in this topic is renewed today because of the wide use of advanced computer software in architectural design process. Computer based design tools that are available for architects today, such as Computer Aided Design (CAD), expand the architect’s ability to experiment with various forms and their potential combinations. Additionally, the equipment that accompanies computers, such as 3D printers and laser cutters, provides the possibility of actually creating those forms with high accuracy. Along with the new means of design expression comes a new challenge for the architectural design process: the perception of design as an algorithmic process, “a computational process for addressing a problem in a finite number of steps. “5 The above changes, on both the practical and theoretical level, influence and may in fact determine the use of ornament in design.

The purpose of this paper is to reveal the influence of advanced computer software and of computational techniques on ornament design. The paper will explore the work of computational techniques in relation to ornament and will investigate how ornament is imported into architectural design through the study of a computational method of visual-based design, that of shape grammars6. In this framework, I will examine two ways that shape grammars address the ornament design problem: they facilitate the analysis and understanding of an existing style and aid in the creation of an original composition. Furthermore, I will develop an example that refers to the second way that shape grammars addresses ornament design, that of creating an original composition. Through this example I will examine a possible application of shape grammars in the programming language Processing.

Ornament: a virtual dimension

In his 2003 article “Architecture, Science, Technology and the Virtual Realm,” Antoine Picon discusses architecture as a non-static condition. He perceives architecture as a “creative principle enabling the constant exchange between the built reality and the domain of knowledge, precepts and rules.”7 Therefore, architecture is always in a state of change, and in that sense attached to “virtual reality”, a term that is used here in a way that is different from the current common usage. Picon defines virtual reality as “nothing but a potential awaiting its full actualization”8 and describes architecture in a similar way, as a condition that embodies tensions and potentials that wait to be actualized. Among these tensions and potentials, he places ornament and defines it as a “virtual dimension” at work in architecture.

Etymologically the word “virtual” derives from the Medieval Latin word virtualis that sequentially derives from virtus/virtue; “the capacity or power adequate to the production of a given effect; energy; strength; potency.”9 Thus, the term “virtual” describes production, effects or potentials that wait to be actualized. Very often, people use the term “virtual reality” as a way to describe something that is not real, such as an image or an environment on a computer screen. This, however, is misleading. Virtual reality is by no means the opposite of the real; rather it refers to the potential states of reality that wait to become actual. Pierre Levy makes clear the distinction between "realization," which is the transformation of the possible to the static, and "actualization," which "implies the production of new qualities a transformation of ideas, a true becoming that feeds the virtual in turn.”10 Thus, “virtual reality” describes potential realities; some of them can be realized and some of them actualized.

In this framework, ornament is a characteristic of architecture that embodies potentiality; in the abstract conception of the form of various motifs, natural or geometrical, ornament encloses a variety of possible applications. It is in the different combination of these motifs and in the possible positions that these could take in the construction that the virtual dimension of ornament lies. A designer actualizes one of these choices and underlies with this action a design intention.

Architects and designers always search for techniques and devices that could address and finally fulfill the desire for variety, potentiality, novelty and continuous change of ornament design. The ensuring of a variety of possible combinations and thus, a variety of ornament potentialities is crucial in the process of ornament design. Additionally, techniques that codify these potentialities and provide ways of organizing and further developing them, help architects to understand and handle the design information. If a designer has a wide range of choices and is able to experiment with them, it is likely that he/she would find the one that best underlies the design intention.

Computers in the ornament-design process

As defined before, ornament belongs to the sphere of virtuality, an abstract field of thoughts that does not necessarily refer to specific and static forms, but rather to the potential results of their combinations. Designers expressed the ideas produced by the above process through sketches and drawings and further explored and improved the initial results by the same graphical means. The images and the environment that surrounded designers was their field of inspiration, a field that they tried to capture and translate into various ornament forms. Some designers were endowed with the ability to actually “see” the various form arrangements around them: that could discern the elements that consist these forms, detach them from the existing synthesis and combine them in a novel form of ornament. In many cases, however, the creation of ornament had nothing to do with novelty and rather referred to a mere copying process of existing forms. In the first case, designers explored the logic that governs a form so as to understand it and then applied it, transformed or not, to new synthesis, a process that led the architect and ornamental designer Owen Jones to the conclusion that “ in the best periods of art, all ornament was rather based upon an observation of the principles which regulate the arrangement of form in nature, than in an attempt to imitate the absolute form of those works.”11

Although there were cases where designers succeeded in understanding the logic of a form, the development of the work was limited to the methods of representation that were available at that time, such as sketches, drawings, plans, sections, facades or perspective and axonometric designs. Even in the creation of a physical model, the available materials and tools of each period were not always adequate in helping the designer to express himself/herself fully and develop further the ideas on the synthesis of ornament. As a result, some complex and complicate ornament arrangements were not expressed in their full potential.

In the last two decades, the ornament-design condition has changed tremendously. Advanced computer software has transformed architecture from a manually driven tool-based design to a computer-driven form-based design. This change occurred in sequential steps, with the role of computer differing each time. When computers were first introduced to architecture, the idea was that they could replace designers. This goal was abandoned, and from 1970 the machine was seen as architect’s assistant, a medium with which the design process, and as a consequence ornament design, could evolve.

On the practical level, new means of expression appear within the realm of the digital medium. First is Computer Aided Design, the well-known CAD system of design, that had as initial goal to speed up the design process and free the designer from the repetitive and monotonous parts of the design process. Additionally, CAD had the ambition of providing the means to explore beyond the manual design process. Secondly, the development of Computer Aided Manufacturing (CAM) and of prototyping machines provided another advantage to the designer in the construction of physical models. Designers were now able to construct a physical model of almost any shape in great accuracy. Through this process the designers were able to test issues related to construction strength, sustainability, friction and thus improve the model.

The development of design tools at the practical level is also reflected in the design of ornament. The introduction of new means of expression provides the designer with the possibility to represent complex forms and experiment with them both in the digital and in the physical world. The Advanced computer technology, however, has not yet reached its full potential. Its use in ornament design mostly refers to design representation and does not address to the development of a design idea. Therefore, the question is how advanced computer technology can go beyond representation and help in design composition. In order to answer this question, designers turn to theory and focus on the procedures that animate the development of form. The understanding of ornament design process becomes very important because “a procedure tells us how to carry out computations of a certain kind”12 and thus provide a deeper understanding of how form is defined and interpreted. Thus, the crucial question for designers is how and to which extent the abstract process of ornament design could be codified and translated into rules so as to create an appropriate input for the machine.

All this research on computational processes has renewed interest in algorithms. Although the algorithm may seem to be a new notion in architecture, that is not the case. On the contrary, algorithms are familiar to architecture; rules of designing, such as building regulations, instructions, or the program for a building, are few of the ways that architects use algorithms to address a design problem. Furthermore, algorithms can be used in design to solve, organize or explore problems with increased visual or organizational complexity; the use of algorithms allows the codifying of information, creating the rules in order to address a design problem. Thus, a computer device is not necessarily needed in an algorithmic process. However, if architects can transfer this process to a computer, they may produce interesting and unexpected results faster.

In this framework, various computational techniques have developed that tried to apply rules and create an algorithm so as to address the issue of ornament design. One of these approaches, that of shape grammars, tries to establish a different language of ornament design by finding different ways of arranging shapes and different ways of describing designs in an algorithmic process. The property of shape grammars is that the created algorithms are based on visual observations of form arrangements. This fact has a great impact on ornament design, because ornament is by default based on the visual effects of architectural compositions. The application of shape grammars on ornament design aims to explain design so as to improve its visual effects

Visual Based design -- The case of Shape Grammars in the design of ornament.

When someone uses the term “algorithm” and “algorithmic design,” he/she usually refers to a computational system of text, symbols and the equations between them. Design, however, mostly relates to points, lines and their possible arrangements to planes and solid geometries. Shape grammars were invented over twenty-five years ago by George Stiny and James Gips in order to combine these two seemingly contradictory fields, mathematics and design; shape grammars propose a way of calculating with shapes. Shape grammars were “one of the earliest algorithmic systems for creating and understanding designs directly through computations with shapes, rather than indirectly through computations with text or symbols”13. This language was invented so as to carry out spatial computations visually. It is a system that uses production rules so as to generate shapes and designs. A basic principal for the creation of these rules is that they are based on what we see. Shape grammars, thus, introduces a new way of approaching design through calculation and shows new paths of experimentation.

Ornament design deals by default with shapes and their possible arrangements in space. Very often the creation of ornament follows specific rules in respect to harmony and order of the composition. These rules, however, are not always obvious or are not consciously followed by the designer. Shape grammars provide a way of codifying the composition information in rules, through which form understanding is easier. Furthermore, new combinations of shapes and rules can result in different and novel ornament compositions.

Shape Grammars: Description

A shape grammar consists of rules and an initial shape.14 The rules apply to the initial shape and to shapes produced by previous rule applications to generate design. Thus, the basic components of a grammar are shapes of any kind, one dimensional, two-dimensional or three-dimensional. The arrangement of these shapes in space defines the spatial relations, which lead to the creation of rules that form the shape grammar. There are four possible spatial transformations that can occur between shapes: translation, rotation, reflection and scale. This process results in different designs.

There are two types of shape grammars: standard grammars and parametric grammars. The case of standard grammars refers to fixed spatial relationships; each rule is defined explicitly by a pair of shapes separated by an arrow. The shape on the left side of the arrow determines the part of a shape to which the rule may apply, whereas the shape on the right side of the arrow describes the shape that results after the application of the rule. On the other hand, parametric grammars allow a variation of spatial relations; instead of a specific shape rule, a wider rule in the form of schemata defines the shape relation implicitly. In this case characteristics of the shapes, such as line-length or angles between lines, can vary. The rules that control this variation result from values that are assigned to those variables.

Application of Shape Grammar to Ornament Design

The use of shape grammar in design addresses two architectural design problems. Firstly, shape grammars help designers to analyze and understand an existing style. Secondly, they allow the development of an original design composition, a process which involves the definition of new languages of design from scratch.

In the first case, shape grammars help the designer to construct the rules that will generate the existing designs and at the same time provide a field for creating new ones in the same style. Therefore, a designer first analyzes an existing shape, and then codifies this information into a set of rules – a grammar – that can be used to generate more shapes in the same general pattern. This property of shape grammars has beneficial effects on the design of ornament.

Ornament is attached to culture. Motifs, combinations of shapes, colors, exaggeration of forms or complete absence of them, all denote the expression of people, an expression related to the social and cultural condition of a geographical area in a specific chronological period. The design of ornament follows these cultural changes and adjusts its values to the social conditions and to the style of each period. Thus, design evolves in time; the act of passing from one stage to the next is followed by the loss of certain design characteristics, the addition of others, or the invention of completely new ones. In most cases, the basic rules that govern the synthesis of ornament remain the same for a long period of time, while their transformations serve as characteristics of areas of specific chronological period of time. The analysis and understanding of a specific style make possible the observation of the style’s travel through time and can result in its reuse in a new context in a new way.

The example of the “meander” motif on Greek geometric pottery is a very nice example that illustrates the beneficial effects of using shape grammars to analyze an existing style. A meander motif used in the ancient Greek period is transformed and used again in the twentieth century, in a new context. The only way to prove the connection between the two motifs is to find the common rules that characterize the two seemingly different compositions. The development of a shape grammar for the Greek meander, discussed on Knight’s article “Transformations of the meander motif on Greek Geometric Pottery,” reveals the basic rules that govern the synthesis of the simple meander design, which marks the beginning of the Geometric style. Knight presents the development of the meander motif through time and examines its transformations. She concludes that the use of the meander motif did not end in ancient Greek period, but continued and reached the twentieth century. The rules that define the basic meander motif made possible the recognition of a motif variation used by the Swiss architect Le Corbusier in his plans for the theoretical project “Radiant City.” The transformation of the meander motif, called redent, was the basic pattern for apartment buildings in the Radiant City. More complex patterns from the redent were produced in the same way that the Late Geometric Potters produced complex meanders: “rows of redents are stacked one on top of another and then shifted by different amounts to create different designs.”15 The second problem that shape grammars deal with is that of original design composition. In this process, the designer defines a vocabulary of shapes and a set of spatial relations between these shapes. Having as a starting point these spatial relations, the designer will try to generate designs by combining them in different ways. The implementation of this process in ornament design -- that is, the application of rules in a set of shapes -- could result in very interesting ornament compositions.

Ornament design deals with shapes and their possible combinations in new compositions. Shape grammars propose a combination technique, which defines a vocabulary of shapes with which the designer wants to experiment. The definition of certain relations in terms of rules between them may lead the designer to new compositional paths. A designer for example can select two rectangles as initial shapes and define a spatial relation between them . Various motifs could be generated in this way. Furthermore, if the designer carries out this computational technique in a computer with the help of the advanced designing programs, then he/she could quickly produce different results. Additionally, the computer can produce other complex motifs in new arrangements in space, motifs and arrangements that the human mind might not think of.

In both cases, shape grammars use a clearly defined set of rules to address the design of ornament. The repetition, however, of a specific set of rules and shapes, in the form of tiles, patterns and motifs, may lead to a monotonous ornament composition. Architects claim that the strict rules of shape grammars leave no space for ambiguity, which is an important characteristic of design, and thus may easily lead to meaningless repetition. It is this characteristic of shape grammars that serves as a main point of critique against them. Monotony, though, can be avoided if something unexpected happens – if, for example a new shape emerges.

Although shape grammars include by default the notion of “emergence” -- the appearance of something that is not explicitly identified in the rules that generated it -- Stiny and Gips did not refer to this notion from the beginning; it was not clear what was happening and thus they referred and treated anything unexpected as a “surprise”. It was only after Stiny realized that emergence is an essential part of design and thus a necessary condition for design that he started to examine possible ways that emergence could occur in shape grammars. Therefore, in shape grammars an “emergent shape is a shape that is not predefined in a grammar, but one that arises or is formed, from the shapes generated by rules applications.”16 In shape grammars, emergence involves not only the creation of an unexpected shape but also the appearance of parts of shapes in a computation process. That means that a shape is not perceived as a definite unit, but as a sum of many indefinite parts. For example, someone can see different shapes in the first shape in figure 9: two squares, four triangles, K shapes, polygons or various lines. According to Knight, this kind of emergence goes along with ambiguity where “shapes can be constructed from certain parts and then decomposed into their parts that become the basis for continuing the computation.”

In most of the cases, when a rule is applied on shapes, the results cannot be defined completely; we cannot predict all the possible derivations. The shapes overlap, intersect and combine their parts in many ways. As a result, new shapes appear that give an impetus for further exploration and experimentation. If it is true that “delight lies somewhere between boredom and confusion”17 then emergence is the vehicle with which we find delight in ornament design.

Practicing shape grammars with Processing.

As mentioned above, shape grammars provide a way of calculating with shapes. The designer defines the rules and then explores their various combinations. Although shape grammars is a computational method that do not necessarily needs a computer as it can be done manually, the use of computer facilitates the process because it produces different results faster and makes possible all kinds of combinations.

Today, the existence of various computer software gives designer the possibility of choosing the one that best fulfill his/her expectations. The present example uses the programming language named Processing, which is based on java and thus it is an object-oriented program. The aim of this attempt was to create a new ornament composition by applying shape grammars in the environment of Processing. The process of creating an original ornament composition needs a vocabulary of shapes and set of spatial relations between these shapes. In the present example the shapes are points, lines and planes. The set of rules defines geometric relations between these shapes.

A secondary goal of this project was to examine the possibility of finding rules and specific geometries in random composition. For this reason the process starts from a random arrangement of shapes and then the rules are applied in sequential steps.

The Process

At the beginning a random arrangement of shapes occurs. The example uses line as the initial shape. Then, the goal is to find relations that derive from the specific arrangement of lines. The process follows sequential steps. Although each step refers to the previous one, it creates a composition of each own, from which a new rule derives. Through this process the composition passes from points to lines and finally results to planes. The first step is to find the intersection points between the random arrangement of lines. Then the lines are erased and a geometric relation that links the points is defined. Each point is connected with a line with two other points: the nearest and the farthest. In the next step the intersection points are erased and pairs of lines are selected. The selection of each pair of lines is between lines of the maximum or the minimum distance. As the process goes on, a quadrilateral is created between the four points of the pair of lines and it is then filled with color. In the last step the lines are erased and I end up with a composition of planes.

Random arrangement of lines Find the intersection points Erase the lines_Keep the points
Create two lines from each point: Erase the intersection points. Select two lines The selection is between
To the nearest and to the farthest point. Keep the lines. the lines with the lines of min or max distance.
Create a quadrilateral between the four points Erase the lines.
of the selected lines_Fill it with color.

Conclusions

Ornamentation, seemingly absent for almost a century, has resurfaced in architecture in a new context and is leading to new forms. With the passing of the design of ornament from a manual driven process to a computer-driven, form-based process, new opportunities arise. In particular, the actualization of the ornament design process through the use of computational techniques, and more specifically the use of algorithms, increases the range of potential compositions of ornament that can occur. As a result, today, more than ever, ornament seems to have many more potentialities that wait to be actualized and is thus closer to fulfilling its “virtual dimension.”

A crucial point in this algorithmic process is how the ornament design information can be codified so that the designer can better understand and thus control the final results. The visual based computational technique of shape grammars provides a system of shapes and rules that attempts to answer the above question and introduce new directions in the design of ornament. The analysis and understanding of existing styles through the creation of appropriate rules provides the designer with the tools to develop new motifs in a new context. With shape grammars and their codification of forms and available shapes, the notion of diversification is intensified in design as opposed to the modernistic trope of homogenization. In addition, the creation of a vocabulary of shapes and rules from scratch could actually serve as the starting point for a novel ornament design, where ornament is not merely decorative style but a language to be communicated. This can be attained through shape emergence and ambiguity that defy any effort of classification and categorization when actualized.

In this framework, the combination of shape grammars with programming languages, such as processing could possible provide an answer to the crucial question of the codification of the ornament design information. Further research on the possible ways that these two techniques of approaching ornament design could be combined needs to be done, in order to achieve compositions characterized by specific logic. The properly structured starting rules will set the designer free to create different kind of compositions by combining the rules in various and infinite ways.

Decrease the number
of the starting lines
Increase the number
of the starting lines
Different results depending on the number of the number of the starting lines.


1 Farshid Moussavi and Michael Kubo, ed., The Function of Ornament (Barcelona: Actar, Harvard University,
Graduate School of Design, 2006).
2 The Collaborative International Dictionary of English, v.048, http://www.dict.org, accessed April 26, 2007..
3 Antoine Picon and Alessandra Ponte ed., Architecture and the Science (New York: Princeton Architectural Press,
2003), 298.
4 Ibid., 297.
5 Kostas Terzidis, Algorithmic Architecture (Burlington: Architectural Press, 2006), 65.
6 George Stiny, Shape Grammars (Cambridge: MIT Press, 2006).
7 Antoine Picon, "Architecture, science, technology and the virtual realm," in Architecture and the Sciences
Exchanging metaphors, ed. Picon A. and Ponte A. Ponte (New York: Princeton Architectural Press, 2003), 298.
8 Ibid., 295.
9 http://www.m-w.com/dictionary, accessed April 26, 2007.
10 Pierre Levy, Becoming virtual: Reality in the Digital Age (NY: Plenum Press, 1998), 58.
11 Edgar Kaufmann, “Architectural coxcombry* or the desire for ornament,” Perspecta vol.5 (1959): 11.
12 George Stiny, “Computing with Form and Meaning in Architecture,” Journal of Architectural Education vol.39
No.1 (1985): 7.
13 http://www.mit.edu/~tknight/IJDC/frameset_abstract.htm.
14 George Stiny, “Computing with Form and Meaning in Architecture,” Journal of Architectural Education vol.39
No.1 (1985): 8.
15 Terry Knight,”Transformations of the meander motif on Greek Geometric pottery,”
http://web.mit.edu/neri/Public/Stiny, accessed May 1, 2007.
•16 Terry Knight, “Computing with Emergence,” Environment and Planning B: Planning and Deign 30 (2003): 125–
155.
17 Ernst Hans Gombrich, The Sense of Order (Oxford: Phaidon Press Limited, 1984): 9.
Pictures
1. http://www.liaoyusheng.com/archives/architecture_design/.
2. http://www.nai.nl/e/extras_e/webfile_hdm/hdm_artists.html.
3. http://www.arcspace.com/books/architecture_now_3/architecture_now_3.html.
4. George Stiny, “Computing with Form and Meaning in Architecture,” Journal of Architectural Education vol.39
No.1 (1985): 8.
5. Terry Knight, ”Transformations of the meander motif on Greek Geometric pottery,” 152.
http://web.mit.edu/neri/Public/Stiny.
6. Ibid., 140.
7. ibid. 167.
8. “fixlecture1slides_final”, http://gb-server-1.mit.edu/search, accessed May 1, 2007.
14
9. George Stiny, “How to calculate with Shapes,” in Formal engineering design synthesis, ed. Cagan J. and
Antonsson E. (NY: Cambridge University Press, 2001), 1-2.

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