.1

.3

[index]

0.[introduction] pgs.2-10

1.[Design Operators] pgs.8-13

pgs.32-39

pgs.14-19

pgs.20-31

6.[Bibliography] pgs.68-69

4.[Digital Design Fabrication]

2.[Digital Design]6.[Summary]

5.[Case studies]

3.[Digital Fabrication]

pgs.36-59

pgs.64-67

2.1.Definition: Digital Design2.2.Frame of reference: History of disassociation2.3.Digital continuum2.4.Digital Bridging

5.1.Rapid prototyping and fabrication operator, Dritsas S.5.2.Tesselion,Philadelphia University Architecture/Marc Fornes, Adrienne Yancone/5.3.Chesa futura/ St. Moritz/ Switzerland/ Hugh Whitehead/ Foster and associates

3.1. Definition: Digital Fabrication3.2.From analogue to digital3.3.From digital to analogue3.4.Two dimensional fabrication 3.5.Subtractive fabrication3.6.Additive fabrication 3.7.Formative fabrication3.8.Assembly

1.1.Definition:Design Operators1.2.Traditional design operators1.3.Computational pro-cesses and operators1.4.Types of computational processes1.5.Documentation of Operators1.6.Rapid prototyping and fabrication operators

4.1.DDF: introduction of the digital design fabrica-tion term4.2.Design models: Design information models.Building Information Models (BIM)4.3.Component design4.4.Mass customization vs mass production4.5.The parameter of scale/ Scale-ability Construction description 6.1.Conclusions

6.2.Experiment

0.[introduction]

.05

image 01: Structural scheme of the Guggenheim Museum in Bilbao and photo from the construction phase (1997). Photo from the buidling of Watercube in Beijing (2007).

In the past few years, a new construction process has been integrated in many architectural projects. This process is supported by the integration of digital produc-tion machines in the building industry. The use of similar technologies has been common practice for many years in other construction areas, such as aeronautics. The main reason for the delay of their adaptation in architecture has been, according to W. Mitchell (Kolarevic B, 2003), the contribution of many different elements in architectural production, typically with clashing interests. Nevertheless, architecture evolved to assimilate these digital production machines and one of the first building applications is the world renowned Guggenheim museum in Bilbao (image 01). In order to better comprehend the architectural imple-mentation of this new reality, it is necessary to study digital design and the context in which it evolved. More specifi-cally, we study the development of computer environments that constitute the basis for every digital design software.

Although digital design is not a new topic in architectural discourse, many of its most important characteristics and extensions still remain untouched. The scope of this paper is to examine the reconnection of design and construction through the introduction of digital production machines in the building process. It is possible to connect the isolated practices of architect, engineer and builder under the umbrella of a cooperative work frame. This is made possible because all the con-tributors of a project can now work on a 3D digital project model that contains construction information even from the very early design stages. This possibility to manage both the design as well as the construction information through digital media supports a new design process. This process is started and developed by the architect, enriched by the engineer and transmitted to the builder through the exchange and update only of digital files. It is obvious that in this process the “design of the design” becomes the-

«We are facing a very important moment of transition, and because of that transition, we are at the same timefacing a crisis. The industrial society is being replaced by an information society, and that transition is changing completely the rules of the game-of all games, including those of architecture», notes Antonino Saggio (Kolarevic B., 2003)

image 02: Operating CNC machines (laser cutting, 5 axis milling, laser cut panel, 6 axis robotic milling)

most important part of the project. In this context, a unique opportunity appears to redefine the role of the architect in relation to construction and to establish him/her as the “information manager,” a contemporary version of the chief-mason. We aim to illustrate how the introduction of digital fabrica-tion in architecture is the missing piece that completes the puzzle of a consistent and coherent digital process, from design to construction. Furthermore, the paper will at-tempt to cast a light on the vague and unknown, for many people, area of digital design and digital production. At the same time, information will be provided on the available technologies to help those who have an interest in this field. For that reason, this paper covers not only the theoretical background that supports digital design but also presents the available technologies on digital production. The mate-rial is split in four chapters. In the first three, the theoreti-cal background is presented: first design operators are analytically described, then the concept of digital design is analyzed, and finally digital production is explored. The last

chapter discusses the concept of DDF and presents three examples/implementations.Last but not least, this paper, is the first attempt to intro-duce in the greek reality a handbook outlining the principles of digital fabrication as well as describing a series of tech-nologies and terms. Such Bibliography was not existing up until the completion of this dissertation.

.07

image 03: a) 3d scanning of a scaled model b) translation of the point cloud in a digital model , c) 3d printed physical model

1.[Design operators]

.09.09

image 04: traditional-analogue (ruler, compass, rapidograph) and contemporary-digital (CAD) design operators

1.1.Definition: Design Operators

Operators are defined as the mechanisms that offer their users the capability to control a process through different sources. William Mitchell (Mitchell, W.J, 1990) defines operators as tools/functions that assess a new design situation. In other words, an operator is a process that takes as input a specific design situation and outputs a new one. (image 04). Design operators are tools based on digital processes that give design-ers the capability to reproduce and evaluate their ideas based on the specific medium (Dritsas S., 2004).

1.2.Traditional design operators

Design operators are not new in architectural design. Architects have always been using them in every phase of design. Nowadays, though, a change is observed. The attributes of “traditional” design operators are re-evaluated, due to the introduction of computers, and are replaced by new ones. Traditional design operators comprise on the one hand a group of physical tools such as pencil and paper, ruler, design compass and navigational compass, and on the other hand a group of abstract fabrications such as axis, grid and diagram. In a computer environment, such as Computer Aided De-sign (C.A.D.), traditional operators are either of less importance or are redefined in order to adjust to the requirements of the new environment. Design opera-tors that maintain strong bonds with the attributes of their analogue medium, which has now changed, slowly become obsolete. The limited use of geomet-rical tools such as the T-square, which used to be a basic design tool for every designer but nowadays is scarcely met in architectural schools, is an example

of the new situation. Nevertheless, the functions of these operators are still in use. For that reason CAD applications have introduced commands of copying-offsetting that perform the function of parallel draw-ing of straight or curved lines and surfaces.In this context, the attribute of the T-square design medium has been redefined not only as far as the operator is concerned, which has been transformed from a tool to a command, but also in terms of its function that now refers not only to one but to many geometrical objects. Furthermore, computer as a design environment provides an ideal setting for the creation of new design operators, while at the same time gives place for an interesting discussion around this topic. As a result new design operators can be created that we could not even imagine in the traditional design setting. For example, geometric surfaces of high complexity and accuracy were unfeasible before the development of the opportunity to process sur-faces with digital design media. The conception and representation in space of such surfaces was either impossible, or extremely taxing. Today, however, the use of a computer allows us to create a design op-

erator that can analyze surfaces of high complexity. It becomes obvious that the innovation of “algorithms” that was introduced by the use of computer design processes led to an ever increasing gap between designer and design, as parts of a process with more and more undetermined operators.

1.3.Computational processes and operators

An important thing to consider with regards to computation procedures, which are typically in the background, is the fact that they actually precede the electronic computer. Computation is the trans-formation of an input to an output. Computation may be performed by people with pencil and paper, with electronic devices, with analogue and digital com-puters (Copeland, 2000). Computations performed with an electronic computer can be described as dis-crete and symbolic. Their attributes were formulated by Alan Turing in 1936 (Dritsas S., 2004) Computation and design are intricately related since the early steps of development of the electronic computer. However, since a historic retrospection exceeds the scope of this paper, their relationship will be viewed under the light of two of their basic characteristics: time compression and expansion of representation capabilities. Early computer applications can be traced in the fields of art and science, not in architecture, and are characterized by an experimental nature. Due to technical restrictions of that time, early experiments were limited to specific applications. In the field of architecture, the innovative work of Ivan Sutherland in the sixties set new horizons and expectations. His application “Sketchpad” (image 05) introduced a new way of interaction between man and machine: an invention that set the foundation for the use of computers in design (Pantazi M, 2006). It is impor-tant to state here that the nature of this development has been and continues to be two-fold: continuous, as well as intermittent. Thus, although initial explora-tions in this area were restricted by the available me-dia, the theoretical developments were outstanding. The most popular applications we use today were first created at those early stages of computer devel-opment. Nevertheless, the adaptation of these new mechanisms in design was not immediate. Designers were coming indirectly in touch with computation through CAD applications. The first tools replaced the existing pencil and paper practices, primarily in the documentation of the design product. CAD systems of previous decades were allowing not only the quick reproduction of construction drawings and their details, but also facilitated the processes of cor-rection and adaptation to new data (Dritsas S., 2004). This change of medium radically affected the means of design representation, which was now happening

digitally by the translation of the paper design sur-face onto the computer screen design surface. The introduction of digital tools in design, from that point on, constituted a decision based primarily on economic factors, such as optimization of production circles and standardization of communication, rather than aesthetic and stylistic ones. Time compression of design was not immediately achieved because, while CAD applications facilitated many processes, at the same time their use demanded the develop-ment of specialized computer training by their users. These fundamental problems were quickly surpassed as the number of computers augmented rapidly, their cost was drastically reduced and they became avail-able and affordable to the masses. Knowledge on CAD applications was accumulated and became ac-cessible. The initial use of these applications, though, could be characterized as transitional and mimic, because it only replaced through copying, existing and established design attitudes without adding something new. These characteristics, of course, al-ways accompany the early phase of medium change, as such “analogues” constitute the mental tools that allow the establishment of knowledge bridges.

As in most cases after the introduction of new technologies, the transitional stage is followed by a phase of acceptance and identity determination. Progressively, the tool - i.e. the computational process - started to shape its identity and to es-tablish alternative work models, beyond those of “blind” copy-pasting of existing ones. One now had the opportunity of spending more time in designing the object through the specific medium and at the same time appreciating and evaluating the mediums’ unique attributes. The emergence and establishment of digital design identity was also assisted by the gradual expansion of the capabilities of geometrical tools, which in turn allowed users to quickly make and evaluate local changes and adjustments. Based on these capabilities, designers could expand the boundaries of their creative thinking. Another step in the establishment of computational processes in design was the attempt of transition in terms of flexibility from the local to the global level, with the introduction of parametric techniques to handle geometry. An interesting observation is the fact that although these technologies had devel-oped from the early stages, their acceptance always lagged behind their development. In this way, design turned towards the logic of process after having been specifically and accurately codified, using a variety of approaches based on rules, restrictions, and relationships. Thus became feasible the ideally multiple repetition of the design action, provoked either by special or generic alterations. As a result, the word “process” became one of the most attrac-tive and popular words in architectural discourse The emerging advantages of computational design .

.11.11

image 05: Ivan Sutherland introduces the Sketchpad image 06: the code of a design operator that works within the envi-ronment of 3d program (RVB script in Rhino).

processes derive from their ability to produce a wide range of solutions, ideally infinite, where design could become an act of selection. The achieved time compression was cumulatively beneficial since it actually expanded the initial phase of design as a thought experiment, as well as the subse-quent phases of optimization and finalization. While the relationship between the time compression offered by computational processes and the larger degree of men-tal experimentation on design may initially sound tenta-tive, the fact remains that by allowing for greater “free” time, the possibility arose to obtain more and improved design solutions. At the same time, the expansion of the representation means forced us to revisit traditional design media and introduced new pathways of design

thinking. This shift in the representation methods con-tributed mostly qualitatively on design, since it placed under scrutiny both our traditional perception tools, as well as our ability to construct new ones.

image 07: visaul representation of the parameters affecting the algorithm for the production of a sheet metal table. (Clemens Weisshaar, Reed Kram).

1.4.Types of computational processes According to S. Dritsas, computational processes can be categorized based on three basic characteristics:a) Complexity.Complexity deals with the fact that inside restricted systems, even when the variables are well known, unpredicted behaviors occurs (Edmonds, 1996). Complexity in a process could be either qualitative or quantitative.

b) Accessibility has to do with the degree of control over the complexity of a process. Accessibility is similarly into theoretical or technical.

c) Compatibility follows the idea of accessibility. When accessibility is no longer an obstacle, then the process is considered transparent. The process is combined with other ones and constitutes common ground, in a way that it no longer stands out com-pared to a design, for example, intention.

1.5.Documentation of Operators

Design operators began as an experiment towards

the creation of mechanisms aiming at complexity and increased accessibility. The intention was to accomplish mechanisms of the maximum possible compatibility. The existence of such mechanisms is not a new condition in design. They constitute an at-tempt to take advantage of the computational possi-bilities offered by digital technologies and are based on the ability of these technologies to deal with the resulting complexity (Dritsas S., 2004). More specifi-cally, design operators that are based on computa-tional processes are personal design sub-processes that allow the possibility of greater design control. Depending on the design domain they focus on, dif-ferent kind of operators appear, such as environment information operators, global generative operators, rapid prototyping and fabrication operators, environ-mental sensitive operators.

1.6.Rapid prototyping&fabrication operators

In this paper, rapid prototyping and fabrication operators will be examined under the light of digital design and production. These operators are the main tools of digital design and offer new design possibili-ties. This comes as a result of their computational capability and their personalization ability, while in relation with the available technology, they provide

.13.13

image 08: translation of the algorithm into code.

an immediate connection between design and con-struction. They are based on the development of micro-applications through programming, known widely as scripting. This type of programming holds the higher degree of atraction between programming languages(images 07,08). The terms high and low describe the distance between code and machine. In other words, a programming language of high degree must be transformed many times up until it executable from a CNC machine (Dritsas S., 2004). The text-based code that the programmer writes is introduced into the programming environment (appli-cation programming interface) of an application and then, through some transformations (p-code, native code), ends up on the level where it is executable by the code of some CAM machine (machine-code, g-code). Therefore, scripting exists between an existing software environment, a CAD application for exam-ple, and its programming interface (the programming language of the specific application), and describes a way of using particular tools of the specific applica-tion based on a code and not based on the graphic interface of the application.The high degree of abstraction that characterizes scripting allow users, with limited experience in programming, to have access to the structure of the

application they have been working on, and to be able to quickly alter some of its functions. In a way, it allows users to reproduce their own personal tools. A typical CAD environment usually offers a great range of tools that the user does not have to create from scratch. Simultaneously, the time needed to adapt to this rather curious way of designing is relatively little if one considers that most of the commands the user has to “adapt” at his/her own will correspond to commands that the application offers in a graphical way with which most of the users are already familiar.New design and production processes induced tre-mendous changes in building geometry and provided unprecedented possibilities to the architects to get back/recapture the supervision of construction they once had. By unifying design, analysis, construc-tion and assembly of buildings with the aid of digital technologies architects and engineers have to rede-fine the relation between design study and design implementation. Furthermore, they have to redefine the term “chief-mason,” under the light of a common digital data basis, as their practices could now be unified bridg-ing, thus, “the gap between design and production, which arose when architects started to make draw-ings,” (Mitchell J, McCullough, 1995) .

2.[Digital design]

.15.15

“This new found ability to generate construction information directly from design information and not the complex curving forms, is what defines the most profound aspect of much of the contemporary architecture. The close relationship that once existed between architecture and construction (what was once the very nature of architectural practice) could potentially re-emerge as an unintended but fortunate outcome of the digital processes of production” Branko Kolarevic (Kolarevic B., 2003)

2.1.Definition: Digital Design New design and production processes induced tre-mendous changes in building geometry and provided unprecedented possibilities to the architects to get back/recapture the supervision of construction they once had. By unifying design, analysis, construction and assembly of buildings with the aid of digital tech-nologies architects and engineers have to redefine the relation between design study and construction. Furthermore, they have to redefine the term “chief-mason,” as under the light of a common digital data basis, their practices could now be unified bridg-ing, thus, “the gap between design and production, which arose when architects started to make draw-ings,” as Mitchell και McCullough (Mitchell J, Mc-Cullough, 1995) noticed.

The term digital design has taken different interpre-tations and during time. In architecture is, usually, connected with representation and manipulation of complex forms and spaces. Nevertheless, the concept of unique digital design processes that differ from traditional analogue ways of designing, mainly alludes a way of design exclusively embedded in a computer environment. For centuries, architects and chief-masons were one thing. The knowledge of construction techniques was connected with architectural production, while the creation of an architectural form demanded firstly the creation of its technique of construction. Design information was also construction information – the one implied the other.

2.2.Frame of reference:

History of disassociation

Chief-masons,” from the masons of ancient Greece until the masons of the Middle ages, were respon-sible for all phases of a building creation, from design studies until construction. Their ruling position in building industry was the result of their ability to deal, mostly, with stone. As time went by, the introduction of new materials and the development of building industry made the supervision of a whole building by architects/chief-masons impossible. For that reason,

they included other craftsmen in the process, a fact that made the production process even more

complex. The tradition, though, of the chief-masons did not survive the socio-politic changes of the Renaissance. Leon Battista Alberti first mentions that architecture differs from construction, setting apart architects and artists from chief-masons and crafts-men due to their intellectual education.

Nevertheless, architecture started to separate from construction towards the end of Renaissance, by one of the most brilliant inventions of the period, that of perspective drawing. However, the introduction of perspective and drafting drawings, as media of communicating the construction information created a gap between architect and craftsman. Craftsmen, so far, were used to oral communication and to the constant presence of the chief-mason and thus could not understand the new way of communication through drawings. Lastly, these new drawings gave the architects the opportunity to approach construc-tion without having immediate contact with the build-ing site.

The division between architect and chief-mason enforced the need of communicating the information through one specific medium, that of drawing (plans, facades, sections, two dimensional representations, perspective drawings), so as all the people involved in construction could communicate, given that the direct contact between them was now lost.

Towards the end of the 19th many architectural firms, such as the well known McKim, Mead and Whited, wanted to have full control of the construction. For that reason they produced a huge number of draw-ings of the building as well as construction detail drawings, while they were deciding on every detail of the building, for the quality of the materials and work and lastly for the payment of the constructors (Ko-larevic B., 2003). Thus, they were creating more and more layers between them and the building site. As Howard Davis mentions “as the system was expand-ing, the role of the general constructor became more powerful while the relationship between architect and craftsmen was diminishing.”

The 20th century brought even more complexity in design and construction, as new materials, technolo-

gies and processes were introduced in building con-struction. The increased complexity was accompa-nied by an augmented expertise and the appearance of technical consultants of different kind. While the complexity of the buildings was increasing and the time needed for design was diminishing, architects were searching ways to form security belts to avoid too much responsibility on the building site. This fact progressively removed architects’ right on making construction decisions and thus the distance between them became even bigger. The contract issued from American Institute of Architects, necessary in order to obtain a building permit, mentions that “the architect has no control, nor is responsible for the construction means, ways and methods” (Kolarevic, 2003).

2.3.Digital continuum

Digital design method could be described as a structured relationship between information and ways of representation that supports design in computer environments. This relationship could run materialization data/inputs or even computational data/inputs. Parametric design programs, such as CATIA,Solidworks,Alpha Cam,Revit, could offer in-

puts/data and representations of a design proposal as descriptions of internal functions of the construction building system(images 09-12). Current digital design definitions still differ between design environments and environments of construc-tion data. The introduction of the concepts of rapid prototyping and digital fabrication tend to diminish these differences in digital design and emphasize the design continuum, materialization and construction.

2.4.Digital Bridging

It is under discussion whereas drawing production arose in building reality due to the necessity of divid-ing design from construction or if its introduction contributed to the realization of this division. Today’s heritage, though, is the law context in which everyone that deals with construction has to accept. A heritage that often demands a great number of drawings, even

.17.17

image 09: restricting parameters for the design of Surface Bridge (Singapore) and mean curvature analysis diagrams (IJP corporation) images 10-12: 3-d representations and models of the bridge (IJP Corpora-tion)

for a project of medium size and complexity. This may seem excessive in the context of Greek reality, where an important discrepancy is been observed between the design studies/projects that follow the law and the realization of them. Nevertheless, this strict law con-text is the construction reality followed in the majority of the states of the European Union and the United States of America.

The allocation and fragmentation of responsibilities is what makes the production of shop drawings neces-sary. In other areas, such as naval engineering, de-signer and constructor often constitute a unity in the face of law. As a result, there is little, if any, need for drawings. Many shipyards have diminish their draw-ing production working directly with one accessible to everyone three-dimensional model, from design until construction. Digital geometric inputs are exported directly from this three-dimensional model and are introduced to automated construction and assembly machines.

Naval engineering and other practices such as aero-nautics directly adopted these new technologies and adjusted their construction line to the new conditions, while something similar did not happen in architec-

ture. This was the result, on the one hand of the fact that designer and constructor were most of the times a single legal entity and on the other hand because these practices did not have to deal with a structure enacted by the law as building construction reality, which is sluggish and relatively negative to drastic changes because it involves clashing interests. Bernhard Franken informs us that Boeing integrate this production method because it could reduce the production costs 20%. Obviously, apart from the rea-sons mentioned above, the economic factor was one of the main ones, if not the most important, for the introduction of these technologies.

Thankfully, digital reality that recomposed from scratches many construction fields, touched architec-ture as well. Many architects immediately responded to this reality and took advantage of the possibilities digital design provided. They could, now, reproduce and provide digital construction data to constructor and construction companies, which were now able to process and then propose accurate material estima-tions and production costs. In these new processes of direct information exchange digital design information is transformed in construction information and vice

versa without the in-between time-consuming and susceptible to mistakes stages of drawing production. The three dimensional model that is being created and controlled by the designer becomes the only source of design and construction information. It em-bodies all the necessary information for the construc-tion of a building. Layers of information are added, enriched and subtracted during the whole design and construction process from architects, engineers and constructors, which are following a predefined work plan. They are, thus, working in cooperation on one digital model from the early design phases.

Such a production model presuppose the unification of all design, analysis, representation and construc-tion tools in a coherent digital environment that could offer information for any qualitative or quantitative element, not only for the design but also for the construction phase. What was at stake from the first appearance of CAD applications, three decades ago, was how the created informational model could facili-tate a project in all stages, from the idea, through de-sign (image 13b,c,d), to construction and completion of the building, while at the same time could provide a digital environment that will allow an easy and without obstacles communication between the people partici-pating in the project.

In any case, such a working model diminishes dra-ing production and if applied in every project stage, it is estimated that there will be a benefit of 28-40% in time construction.(Kolarevic, 2004) This fact, though, presupposes changes in the law context that deter-mines construction industry, where drawings consti-tute the only area of reference of the people involved. Frank Gehry’s architectural firm is pioneer in this field as it introduced this working model in projects even from the late eighties. The huge in size “fish sculpture” in the entrance of the shopping mall of the Olympic village in Barcelona (1992), constitutes one of the first projects designed and constructed by digital media (image 13a).

Economical and temporal restrictions forced Jim Glymph, firm’s associate, to look for digital solution in construction in order to accurately produce and assembly the complex geometry of the sculpture (image). Model produced in CATIA’s (Computer Aided Three-dimensional Interactive Application) program-ming environment – design and construction program used mostly in aeronautics – are for Gehry’s firm and associates, the only source of design and construc-tion information.As an important step away from the existing situation, the three-dimensional model has a key position in construction study and is the one

.19.19

image 13: strctural schemes of: a) the “Fish Sculpture”,in Barcelona (Gehry Architects),b) the hollow of a cargo shipd) BMW “Bubble” pavillion in Germany (B. Franken Architetekten) ,d) the “Surface Bridge” in Singapore (IJP Corporation),

from which all the information are exported during the production process of the different building parts and generally of the whole construction. This fact makes the work of the specific architect extremely important for the architectural world.

3.[Digital Fabrication]

.21.21

image 14: graphic representation of the digital fabrication of a table. ( Clemens Weisshaar, Reed Kram)

3.1.Definition: Digital Fabrication

The digital period redefines the relationship between architectural design and production by introducing a direct conjunction between a design concept and its realization. Building projects are not only conceived and organized with the aid of digital media, but also realized through equivalent digital processes, known also as “file to factory.” The challenge of constructing architects’ morphological explorations of the late eight-ies transformed the question of examining the realization of certain forms to a matter of seeking appropriate tools to take advantage of digital production possibilities that started to appear.

image 15: 3d robotic digitizer “Micro-scribe”

image 16: 3d laser scanner image 17: 3d scanner for site supervision

.από το αναλογικό στο ψηφιακό

.3-dimensional scanning/τρισδιάστατη σάρωση αντικειμένων

Για πολλούς αρχιτέκτονες, κατά την φάση του σχεδιασμού, η αμεσότητα ενός προπλάσματος είναι σαφώς προτιμότερη από την επίπεδη επεξεργασία επιφανειών και γραμμών στο χαρτί ή στην οθόνη του υπολογιστή. Ιδιαίτερα λοιπόν στα αρχικά στάδια ανάπτυξης τους οι ψηφιακές τεχνολογίες χρησιμοποιούνταν λιγότερο ως μέσο πρόσληψης μιας ιδέας αλλά περισσότερο ως μέσο μετάγραφής της από τον φυσικό χώρο, όπου είχε την μορφή προπλάσματος, στον ψηφιακό, ως κωδικοποιημένη πλέον γεωμετρική πληροφορία. Η διαδικασία αυτή της μεταγραφής είναι το αντίστροφο της κατασκευής με ψηφιακά μέσα. Με την βοήθεια τεχνικών τρισδιάστατης σάρωσης, παράγεται μια ψηφιακή αναπαράσταση ενός φυσικού μοντέλου. Μια ομάδα σημείων, γνωστή και με τον όρο «σύννεφο σημείων» (point cloud), συλλέγεται μέσω της σάρωσης και στην συνεχεία μεταγράφεται σε σημεία έλεγχου μιας επιφάνειας η οποία περιγράφει κατά μεγάλη προσέγγιση την γεωμετρία του προπλάσματος.Μια κοινή μέθοδος τρισδιάστατης σάρωσης περιλαμβάνει την χρήση ενός εργαλείου ψηφιοποίησης το οποίο ανιχνεύει στοιχεία της επιφάνειας του προπλάσματος (εικόνα 15). Η διαδικασία αυτή μπορεί να γίνει είτε χειροκίνητα με έναν ψηφιοποιητικό βραχίονα των οποίο ο χειριστής εφαρμόζει σε πολλαπλά σημεία, είτε αυτόματα με την χρήση μιας συσκευής μέτρησης συντεταγμένων, η οποία μέσω ενός σένσορα διατηρείται μηχανικά σε επαφή με την επιφάνεια του υπό σάρωση αντικειμένου(εικόνα 16).

Εναλλακτικά χρησιμοποιούνται οι εξ’ αποστάσεως μέθοδοι σάρωσης, οι οποίες απαιτούν τη χρήση δαπανηρών συσκευών, αλλά είναι σαφώς πιο γρήγορες, ακριβείς και λιγότερο κουραστικές στη χρήση. Οι συσκευές αυτές, ανά διαστήματα προβάλλουν ακτίνες laser στην επιφάνεια του προπλάσματος, δημιουργώντας συστάδες σημείων ή γραμμών σε αυτήν, οι οποίες καταγράφονται από δύο συνήθως κάμερες. Από τις καταγεγραμμένες εικόνες, μέσω τεχνικών φωτογραμμετρίας παράγεται ένα τρισδιάστατο ψηφιακό μοντέλο, το οποίο μπορεί να εξαχθεί σε διάφορους τύπους αρχείων για την περαιτέρω ψηφιακή του επεξεργασία.Η τρισδιάστατη σάρωση, πέραν της περίπτωσης ενός προπλάσματος, μπορεί να εφαρμοστεί για την αποτύπωση μιας χτισμένης οικοδομής ή ενός ολόκληρου τοπίου, ενώ πρόσφατα η χρήση της απαντάται και σε εργοτάξια ως ελεγκτικός μηχανισμός για την ακριβή τοποθέτηση των δομικών στοιχειών (εικόνα 17) αλλά και για την παρατήρηση τυχόν αποκλίσεων και σφαλμάτων κατά την φάση της κατασκευής (Kolarevic B., 2003)

3.2.From analogue to digital

.3-dimensional scanning/

During design, many architects prefer working with models, because they provide a three-dimensional view of the project, rather than working in the two dimensional surface of paper or computer screen. Therefore, in the first stages of their development, digital technologies were used mainly as means of translating a model form physical to digital space through coded geometric information and not as a means of conceiving an idea. This translation process is the opposite of digital design construction. The use of three-dimensional scanning technologies aids to produce a digital representation of a physical model. During scanning process a group of points, known also as “point cloud,” is being selected and is then translated to the control points of a surface, which can describe the scanned object in great detail.

A common method of three-dimensional scanning comprises the use of a digital tool that traces ele-ments on the model’s surface. This process could happen either by hand with a digital arm that the user apply in multiple points, or automatically by a device that counts coordinates, which by a sensor stays mechanically in touch with the surface of the scanned object.

Alternatively, distance scanning methods that demand the use of expensive machines are used. These ma-chines are faster, more accurate and less stressful in use and they work by periodically projecting laser rays onto the surface of the model, which create clump of points or lines onto it. This process is usually record

ed by two cameras. Three-dimensional scanning, apart from the models, could be applied to imprint an existing building or a site. Also technologies like MRI (Magnetic resonance imagin) scanning, mostly used in medicine to visual-ise body’s internal structures are being introduced for scanning materials/ Last but not least, has been used in construction sites as control mechanism not only for an accurate placement of the building elements but also for observing and preventing mistakes and deviations during the construction process.

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image 19: SLA 3d printer image 18: “3DP scribe” 3d printer

3.3.From digital to analogue

.digital fabrication/

The longstanding use of Euclidian Geometry led to the creation of design tool-operators, such as the ruler and compass, for the production of lines and circles on paper and the equivalent machines for their mate-rial production / materialization. Consequently, as Branko Kolarevic ( Kolarevic B., 2003) mentions “the conception of an architectural form entailed the con-ception of its method of construction and vice versa .”

A typical example of this condition is the dome of Santa Maria del Fiore cathedral in Florence, for which the period’s available techniques and methods did not allow its design and construction, as it was exceed-ing even the size of Pantheon’s dome Rome. Filipo Brunellesci provided a solution based on his invention of a machine to elevate materials. Therefore, archi-tects designed what they could construct and vice versa. Representation and architectural production had a mutual relationship, which still exists in the digi-tal era. What changes in time is the level of consis-tency between them.

Thus, contemporary architects take advantage of the new construction technology possibilities; being able to design with them provide a better overview of the architectural production and the project overall. Basi-cally, computer offers an alternative view in design process, which many architects consider it to be more complete. This happens because it is now possible the three-dimensional model to contain information that constructors may translate and use directly as data to manipulate digitally controlled construction

machines. An increasing number of projects, of differ-ent size and budget, are accomplished with the aid of new technologies based on this principal in reason-able time and financial boundaries.

This direction is generally known with the term digital fabrication. This field incorporates technologies of Rapid Pro-totyping for design and CAD-CAM (computer aided design/computer aided manufacturing) for construc-tion (Kolarevic, 2003).

Rapid Prototyping (RP) was first applied in the mid eighties by product designers for design ideas’ presentation through physical models in 1:1 scale that were functioning as construction prototypes. The conventional way to create a construction model starts from a three-dimensional model from which a special file type is exported that is then recognizable by a machine. This machine builds the model in one or two days. RP uses machines that constitute a small replica of the machines that are used in industry.The term CAD/CAM basically refers to industrial object reproduction from digital models. It describes the technology that sends on the construction of a model in 1:1 scale and not only the construction of a prototype.

Στα μηχανήματα τεχνολογίας CNC, ένα υπολογιστικό σύστημα διαχειρίζεται την κίνηση και τις λειτουργίες της κεφαλής χρησιμοποιώντας ένα σύνολο κωδικοποιημένων οδηγιών.Η γεωμετρία εισάγεται σε ένα λογισμικό επεξεργασίας δευτέρου βαθμού, (post-processing software) το οποίο αναπαράγει αριθμητικά τις οδηγίες οι οποίες μετά δίνονται ως δεδομένα στην συσκευή. Οι υπολογιστικές, αριθμητικά ελεγχόμενες οδηγίες (computer numeri-cally controlled) ελέγχουν την κίνηση, την ταχύτητα και τη συχνότητα περιστροφής της κεφαλής και των κατευθυντήριων μοτέρ, καθώς επίσης και την αλλαγή αρίδων, την παροχή ψυκτικού και άλλες λειτουργικές παραμέτρους της συσκευής. Καθώς η αφαίρεση όγκου για την μορφοποίηση ενός στερεού μπορεί να γίνει με πολλαπλούς τρόπους, η αναπαραγωγή ενός κατάλληλου “πλάνου” διαδρομής της κεφαλής, δεν είναι απλή υπόθεση. Το πλάνο αυτό εκφράζεται με ένα CNC πρόγραμμα, το οποίο δεν είναι κάτι άλλο από μια σειρά κωδικοποιημένων εντολών τις οποίες το μηχάνημα εκτελεί (G code).Τα CNC προγράμματα είναι φτιαγμένα από εντολές, οι οποίες αποτελούνται από λέξεις, καθεμία από τις οποίες έχει ένα γράμμα ως διεύθυνση και μια σχετική αριθμητική τιμή. Οι αποκαλούμενες προεργαστικές λειτουργίες, οι οποίες για παράδειγμα ελέγχουν την κίνηση της κεφαλής σημαίνονται πολλές φορές με το γράμμα G. Σε ένα τυπικό CNC πρόγραμμα, η πλειοψηφία των “λέξεών” είναι οι προεργαστικές αυτές λειτουργίες. Για τον λόγο αυτό, ο CNC κώδικας, πολλές φορές αναφέρεται ως κώδικας-G, μεταξύ των χειριστών μηχανημάτων CAM ( computer aided manufacturing).

Παρακάτω αναφέρονται αναλυτικά οι τέσσερις τύποι μηχανημάτων CNC καθώς επίσης και η διαδικασία της συναρμολόγησης, η οποία αποτελεί αναπόσπαστο κομμάτι του digital fabrication.

Υπάρχουν τέσσερις κοινοί τύποι συσκευών Rapid proto-typing και CAD/CAM. Τους τύπους αυτούς περιγράφουμε εν συντομία με τον όρο, συσκευές CNC (computer numerical control)/cutting and milling devices. Αναφορικά είναι οι εξής:-2D cutting devices (vinyl, laser cutters)/ (εικόνα 22)-subtractive devices (milling machines)/ (εικόνα 19)-additive manufacturing devices / -formative manufacturing devices/

Η τεχνική της ογκοαφαίρεσης (εικόνα 19) είναι η παλαιότερη μορφή ψηφιακής κατασκευής. Τα πρώτα παραδείγματα με την χρήση της τεχνικής αυτής στον τομέα της αρχιτεκτονικής συναντώνται στις αρχές του 1970 στην Αγγλία για την παραγωγή αρχιτεκτονικών μοντέλων. Μεγάλα αρχιτεκτονικά γραφεία στις Ηνωμένες Πολιτείες όπως οι Skidmore, Owings and Merrill’s (SOM) από το Σικάγο, έχουν χρησιμοποιήσει εκτεταμένα τεχνικές CAD-CAM για την παραγωγή αρχιτεκτονικών μοντέλων και για μελέτες κατασκευαστικών συναρμογών. Στις αρχές της δεκαετίας του 1990, αυτοματοποιημένες συσκευές όγκο-αφαίρεσης χρησιμοποιούνται για την επεξεργασία οικοδομικών υλικών, όπως τις πέτρες για τον καθεδρικό του Αγ. Ιωάννη στη Νέα Υόρκη, και τις κολώνες της Sagrada Familia στην Βαρκελώνη. Η μελέτη του Frank Gehry για ένα συναυλιακό κέντρο της Walt Disney στο Los Angeles αποτελεί το πρώτο παράδειγμα χρήσης τεχνολογίας CAD/CAM για την παραγωγή λιθοδομής. Για το αρχικό μοντέλο ενός τμήματος του κτιρίου με διπλή καμπυλότητα, πέτρινα panel κόπηκαν και επεξεργαστήκαν σε κλίμακα 1:1 στην Ιταλία και εν συνεχεία μεταφέρθηκαν μέσω θαλάσσης στο Los An-geles ,όπου και συναρμολογήθηκαν επί τόπου πάνω σε μεταλλικό σκελετό.Η τεχνολογία CAD-CAM εφαρμόζεται πλέον με ποικίλους τρόπους στην αρχιτεκτονική όπως για την κατασκευή καλουπιών (εκτός εργοταξίου) και την επί τόπου χύτευση τους, καθώς επίσης και για την μορφοποίηση υαλοπινάκων με πολύπλοκη γεωμετρία.

There are four common types of Rapid prototyping and CAD/CAM machines that are condensed under the term CNC (computer numerical control)/cutting and milling devices.

-2D cutting devices (laser,water jet cutters etc)/-subtractive devices (milling machines)/-additive manufacturing devices / -formative manufacturing devices/

The technique of mass extracting is the oldest form of digital construction/fabrication. In the field of architecture, the first examples of this technique use happened at the beginning of the seventies in Eng-land for architectural model production. Well known architectural firms in United States of America, such as Skidmore, Owings and Merrill’s (SOM) in Chicago have extensively used CAD-CAM techniques for architectural model creation and for studies on con-struction assemblies.

At the beginning of nineties, automated machines of mass-subtraction are used for processing building materials, such as the stones for Saint John’s Cathe-dral in New York, and Sagrada Familia’s columns in Barcelona. Frank Gehry’s study for Walt Disney con-cert hall in Los Angeles constitutes the first example of using CAD-CAM technology for stonework con-struction. For the initial model of a building part with double curvature, stone panels were processed in 1:1 scale and were milled in Italy. They were then trans-ported through sea to Los Angeles where they were assembled on site on a metal frame.

CAD-CAM technology is now applied in multiple ways in architecture; constructing molds (outside the

building site) and in situ casting concrete into them or morphing glass panels with complex geometry.

In CNC (computer numerically controlled) machines a computational system deals with the movement and the functions of the head by using a group of coded guidelines. The geometry is introduced in a post-processing software that numerically reproduces the guidelines that afterwards serve as device inputs. The computational, numerically controlled guidelines check movement, speed and frequency of the head evasion and the directional motor, as well as the mill-ing bit change, the refrigerant supply and other func-tional device parameters. As morphing a solid object through mass-subtraction could happen in multiple ways, the reproduction of a suitable toolpath for is not an easy case. This toolpath is expressed through a CNC executable program that is no more than a sequence of coded commands the machine runs.

CNC programs are made of word commands, each one of which has a letter as address and a relative numerical value. The so called procedural functions, which for example control the movement of the head, are usually denoted with the letter G. In a typical CNC program, the majority of “words” are these procedural functions. For that reason, the users of CAM (comput-er aided manufacturing) machines often refer to CNC code as G-code.

In the following parts, four CNC machine technologies will be described as well as the process of assembly, Both constitute an important part of digital fabrication.

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image 22: CNC plasma cutter

image21: Laser cutterimage 20: CNC milling machine

image 23: 2d vinyl cutter

image 25: water jet nozzle and diagrammatic section

image 26: Movement analysis diagram of the head of a 3 and 5-axis milling machine.

image 24: Waterjet cutter

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3.4.Two dimensional fabrication-2D cutting devices (laser,water-jet,vinyl cutters)

Two-dimensional cut with CNC machines is the most common type of digital fabrication. CNC machines range in size and accordingly the surfaces they can process are of different sizes (image). The existing cutting technolo-gies, such as the laser-cutter, the water-jet-cutter and the plasma-cutter allow movement in two directions, either of the head-cutter or of the surface upon which the material is placed (placed on panels of specific dimensions) or a combination of the two. In plasma-cutter, an electric arc is transmitted through a motor jet of compressed gas to the head cutter. In that way the gas is transformed to plasma with the aid of high temperature (25000F), which is then retransformed into gas as it transfers the heat to the cut-ting area.

In water-cutter, a motor of high pressure transmits wa-ter in combination with solid polishing particles into a small diameter end effector (nozzle). Thus, the mixture is transformed to a focused beam that causes immediate erosion. As a result, clear and accurate cuts are being produced.

In laser-cutter, a high frequent bundle of infra-red light is being used in combination with a motor of ejecting gas of high pressure (CO2) to locally melt or burn the cut mate-rial.

In between these technologies, huge differences exist as far as the material that could be processed, the maximum cutting depth and the time needed are concerned. Thus, while the laser -cutter machines could cut materials that absorb light radiation (i.e. wood), water-cutting machines could cut almost all material. Laser-cutter machines could cut efficiently and in short period of time cross-sections of 16mm, while water-cutting machines could cut larger cross-sections (until 38cm) of even hard materials, such as titanium.

3.5.Subtractive fabrication -subtractive devices (milling machines)

The mass-subtraction machines function upon the subtraction of specific material mass from solids, by using electro-chemist-mechanic-subtractive procedures (multi axis milling) (image). The material milling could be axis, surface of mass restricted. In the axis restricted devices, such as the lathe, the part of the material that is under process could be moving around an axis of evasion, while the head has two axis of movement. The surface restricted devices work exactly as the cutting devices men-tioned above.

The milling process of three-dimensional solids is the direct development of two-dimensional cutting. Furthermore, three-dimensional material subtraction is possible with the addition of the head’s ability to move in another axis. Due to the inherited attri-butes of the three-dimensional material milling, the range of the forms that could be produced with the aid of these machines is limited. For that reason, machines with 4 and 5 directional movements have been imported. In the machines of 4 directions, another evasion axis is added either to the head or to the devices’ working surface. In the machines of 5 directions, both head and working surface have evasion ability, maximizing, thus, the ways the head could be adjusted to the solid. In that way, a wider range of shapes could be provided.

Tools that are placed in the head vary in size de-pending on the work phase. Milling tools of larger cross-section are used for material subtraction, while ones of smaller cross-sections are used for surfacing/finishing. The speed of the end effector could be adjusted according to hardness or other material attributes.

.additive fabrication/ προσθετική κατασκευή/

/additive manufacturing devices/

H προσθετική κατασκευή εμπεριέχει την κατά βήμα μορφοποίηση ενός αντικειμένου με την πρόσθεση υλικού σε επίπεδα, ακλουθώντας την αντίστροφη διαδικασία από αύτη της όγκο-αφαιρετικής κατασκευής. Αναφέρεται συχνά ως layered manufacturing, rapid prototyping, solid free form fabrication ή desktop manu-facturing. Όλες οι τεχνολογίες προσθετικής κατασκευής μοιράζονται την ίδια λογική όσον αφορά την ανάλυση του ψηφιακού μοντέλου σε επίπεδα-στρώσεις. Η πληροφορία για το κάθε επίπεδο-στρώση μεταφέρεται στην κεφαλή της συσκευής και το φυσικό μοντέλο παράγεται σε αλληλεπίθετα στρώματα.Μετά την εισαγωγή στο εμπόριο μιας συσκευής βασισμένης στον παραπάνω τρόπο λειτουργίας, γνωστό επίσης και ως στερεολιθογραφία, από την εταιρεία 3d systems, μια σειρά αντίστοιχων συσκευών έχει εμφανιστεί. Οι συσκευές αυτές χρησιμοποιούν μια πλειάδα υλικών και διαδικασιών πήξης με βάση την φωτεινή ακτινοβολία, την θερμική ακτινοβολία και την εφαρμογή χημικών.

-Η στερεολιθογραφία/SLΑ βασίζεται σε πολυμερή στοιχεία υγρής μορφής, το οποία στερεοποιούνται όταν εκτίθενται στην laser ακτινοβολία. Η ακτίνα της κεφαλής διαγράφει μια τομή του μοντέλου, μέσα σε ένα δοχείο με το ευπαθές στην ακτινοβολία υγρό πολυμερές. Στην περιοχή που έχει δεχτεί την ακτινοβολία, στο “ίχνος” δηλαδή της κίνησης της κεφαλής, δημιουργείται ένα λεπτό στρώμα στερεού υλικού. Το στερεοποιημένο τμήμα, το οποίο ακουμπά πάνω σε μια βυθισμένη επιφάνεια, υποβαθμίζεται κατά ένα βήμα μέσα στο δοχείο και η ακτίνα διαγράφει την επόμενη τομή του μοντέλου. Η διαδικασία αυτή επαναλαμβάνεται για όλα τα επίπεδα στα οποία έχει αναλυθεί το μοντέλο μέχρι ολοκλήρωσης του (εικόνα 31). Στο τέλος της διαδικασίας η επιφάνεια με το στερεοποιημένο μοντέλο ανασύρεται από το δοχείο, το μοντέλο πήζει περαιτέρω και αφαιρείται τυχόν επιπλέον υλικό.

-Στην selective laser sintering/SLS (επιλεκτική συμπύκνωση με laser) τεχνολογία, η ακτίνα laser διαγράφοντας πάλι την τομή ενός αντικειμένου, συμπυκνώνει ανά στρώματα σκόνη μετάλλου, μορφοποιώντας έτσι το αντικείμενο (εικόνες 28,29).-Στην 3d printing/3DP τεχνολογία στρώσεις κεραμικής πούδρας συγκολλούνται με την ίδια λογική για να δημιουργήσουν το αντικείμενο (εικόνα 27).-Στην Laminated object Manufacture/LOM τεχνολογία, φύλλα υλικού (χαρτί ή πλαστικό), είτε σε μορφή ρολού συγκολλούνται μεταξύ τους (τεχνική της φύλλωσης-lamination), και στην συνέχεια κόβονται με laser-Στην Fused Deposition Modeling/FDΜ τεχνολογία κάθε τομή του υπό κατασκευή αντικειμένου παράγεται με την τήξη ενός πλαστικού νήματος, το οποίο στερεοποιείται με την έκθεση του σε κρύο αέρα (εικόνα 30).-Στην Multi-jet Manufacture/MJM τεχνολογία μια τροποποιημένη κεφαλή εκκρίνει λιωμένο θερμοπλαστικό κερί σε πολύ λεπτές στρώσεις, την μια μετά την άλλη, για την δημιουργία τρισδιάστατων στερεών σωμάτων.

Λόγω βέβαια του περιορισμένου μεγέθους των αντικειμένων που μπορούν να παραχθούν με τις παραπάνω τεχνολογίες αλλά και τους παρατεταμένους χρόνους κατασκευής, έχουν περιορισμένη εφαρμογή στον αρχιτεκτονικό σχεδιασμό και κατασκευή. Στον σχεδιασμό κατά κύριο λόγο χρησιμοποιούνται για την παραγωγή ογκομετρικών με πολύπλοκη καμπύλη γεωμετρία, ενώ στην κατασκευή για την μαζική παραγωγή εξαρτημάτων, όπως μεταλλικά στοιχεία ελαφρών μεταλλικών κατασκευών.Πρόσφατα βέβαια, διεξάγεται έρευνα για την κατασκευή μεγαλύτερης κλίμακας δομικών στοιχειών με τον ψεκασμό κονιάματος. Έτσι, καθώς ο ψεκασμός του υλικού ελέγχεται ψηφιακά, είναι δυνατή η ακριβής πρόσθεση υλικού σημειακά για λόγους ενίσχυσης αλλά και λοιπών στοιχείων, όπως αισθητήρες και θερμοπομπούς, οι οποίοι μπορούν έτσι να ενσωματωθούν στην κατασκευή με ένα πλήρως αυτοματοποιημένο τρόπο.

3.6.Additive fabrication-additive manufacturing devices

Additive fabrication describes the step by step morphing of an object by adding material in layers, following the reverse process of the mass-subtrac-tive fabrication. Often it is mentioned as layered manufacturing, rapid prototyping, solid free form fabrication or desktop manufacturing. All additive fabrication technologies share the same concept as far as it concerns the digital model analysis in lay-ers. The information for each layer is transferred to the device’s head and the physical model is being produced in successive layers. The most common additive fabrication technologies are:

-SLA (Stereo-lithography). 3d-systems Company was the first to introduce in the market a device based on the above way of function. After that, a succession of similar devices appeared. These devices use multiple materials and clot processes based on light and/or thermal radiation as well as chemicals’ application.The technology is based on polymer liquid materials, which become solid when exposed to laser radiation. Head ray creates a section of the model inside a vat that contains the susceptible to radiation liquid polymer. The trace of the nozzle’s toolpath, is the area where radiation is being applied,and solidifies in a rougly 1/10 mm increment. This layer, which rests on a “sinking” surface, is moved one step lower into the container and the ray creates the next model section. This process is repeated for all layers, in which the model is analyzed, until its completion. Towards the end of the process the surface with the solid model is taken out of the container, the model further clots and the excess material is being subtracted.

-SLS technology (Selective Laser Sintering), in this technology the laser ray creates sections of an object and then condenses in successive layers metal powder, forming, thus, the object. -3DP technology, layers of ceramic powder are con-nected, in the same concept, to create an object. -LOM technology ( Laminated Object Manufactur-ing), material either in sheets (paper of plastic), or in rolls are connected (lamination technology) and are

then cut with laser.-FDP technology (Fused Deposition Modeling), In this technology a semi-liquid material -- and most usually a hot thermoplastic -- is extruded from a temperature-controlled print head to produce fairly robust objects to a high degree of accuracy. A key benefit of this technique is that objects can be made of out of exactly the same thermoplastics used in traditional injection moulding. Most FDM 3D print-ers can print with both ABS (acrylonitrile butadiene styrene), as well as a biodegradable bioplastic called PLA (polylactic acid) that is produced from organic alternatives to oil

-MJM (Multi-jet Manufacturing). As an alternative to FDM, a technology, developed by Objet, is Multi-Jet-Manufacturing or Polyjet Matrix. This jets two liquid photocurable polymers from a multiple nozzle print head. Each object’s layer is cured by a UV light immediately after it has been printed. One of the key benefits of this process is that it allows printing to take place in multiple materials simply by varying the combination of the photocurable polymers jetted from the print head. You can learn more about this very impressive technology

The above mentioned technologies since their in-troduction in the 80’s have had limited applications in architectural design and construction due to the narrow range of object sizes they could produce and the prolonged construction time needed. They are used, though, in design mostly for the production of solids with complex curvy geometry and in construc-tion for the mass production of components, such as metal parts of light metal constructions. Since some years now, there is an ongoing research on the construction of bigger scale structural parts by spraying mortar. Therefore, as the deposited material is digitally controlled, it is possible not only to accurately add material in specific points for strengthening reasons, but also to alter its mechani-cal properties locally (i.e. elasticity) as well as add other parts such as sensors and thermo-transmit-ters, which could be now incorporated to the con-struction with a totally automated technique.

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image 27: working diagram of 3DP 3d-printerimage 28,29: working dia-grams of a SLS 3d printer

image 30: working diagram of a FDM 3d printerimage 31: working diagram of an SLA 3d printer

image 32: Production of foam molds with CNC machine for the in situ casting and digital controlled assembling of wall panes for the Zollhof office building complex in Duesseldorf (Gehry Architects)

.formative fabrication/ μορφοποιητική κατασκευή/

/formative manufacturing devices/

Στη μορφοποιητική κατασκευή μηχανικές δυνάμεις, περιοριστικά καλούπια, θερμότητα ή ατμός εφαρμόζονται πάνω στο υπό επεξεργασία υλικό. Ο σκοπός είναι να προσδώσουν την επιθυμητή μορφή μέσω του ανασχηματισμού ή τη παραμόρφωσης, ως προς έναν άξονα είτε ως προς μια επιφάνεια αναφοράς. Για παράδειγμα, το ανασχηματισμένο υλικό μπορεί να έχει υποστεί πλαστική παραμόρφωση μέσω διαδικασιών όπως η πέραν της ελαστικής του αντοχής στρέβλωση. Πιθανή είναι ακόμη η σημειακή θέρμανση του και κατόπιν η κάμψη του. Η μορφή σύνθετων επιφανειών με διπλή καμπυλότητα μπορεί να προσεγγιστεί με την περιγραφή της γεωμετρίας τους από σειρές, ρυθμίζομενων καθ’ ύψος, αριθμητικά ελεγχόμενων καρφιτσών. Κάθε καρφίτσα αντιστοιχεί σε ένα σημείο της πολύπλοκης γεωμετρικά επιφάνειας. Η τεχνική αυτή χρησιμοποιείται για την μορφοποίηση υαλοπινάκων, ελασμάτων πλαστικού καθώς και καμπύλων μεταλλικών επιφανειών (εικόνα 32). Καμπύλες επιφάνειες, κατά μια μόνο διεύθυνση, μπορούν να παραχθούν με την αριθμητικά ελεγχόμενη κάμψη λεπτών ράβδων, σωλήνων, ή λωρίδων κάποιου ελαστικού υλικού (π.χ. ατσάλι, ξύλο), που λειτουργούν ως οδηγοί για την μορφοποίηση του εκάστοτε υλικού.

3.7.Formative fabrication-formative manufacturing devices

In formative manufacturing mechanical forces, restricting molds, heating or steam are applied on the processed object. The aim is to achieve the desired shape by causing the plastic defor-mation of the material in one or multiple axis. For example, lateral forces above steel’s elas-ticity limit might be applied to a reinforcement so that it can be permanently shaped into a desired form. Another common technique is the application of high temperature locally and the direct bending of the exposed area. The shape of doubly curved surfaces can be approximated with the description of any planar geometry by a gird of adjustable in height metallic pins. Each pin corresponds to the UV (contol) point of a given surface. This technique is mostly used for the morphing of glass panels as well plastic and metal sheets. Surfaces that are curved along on axis can be fabricated by the numeric control of thin rods, pipes or stripes of an elastic material (i.e. wood, steel), which serve as guides for the morphing of a corresponding material

3.8.Assembly-assembly devices and mechanisms

The assembly process constitutes an essential part of digital fabrication and refers to the com-position of the different building components of an object (i.e. building, furniture) in one piece. It functions as a control process for fabrication, as it directly reveals possible weak connecting points even from the early stages of the design process. At the same time it introduces a very important design factor; the ability to design parts with multiple connection possibilities. he in situ digital manipulation of a building assembly increases the concept of its digital fabrication.

The use of digital models could facilitate the accurate placement of every structural object to the appropriate position. Traditionally, builders consulted drafting drawings for dimensions and coordination and by in situ measurements (me-ter, plumb etc), suitable inscriptions and started to build. Nowadays, in many construction sites all over the world, new digital controlled tech-niques, such as the electronic levelling and area measuring that are based on a universal refer-ence system (GPRS) are used for the accurate assembly of structural elements.

Annette LeCuyer, which was involved in the construction of Guggenheim Museum in Bilbao, informs us that “the building was constructed without in situ measurements ”. During the pro-duction phase of the structural elements

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image 32: Production of foam molds with CNC machine for the in situ casting and digital controlled assembling of wall panes for the Zollhof office building complex in Duesseldorf (Gehry Architects)

of the building each one of them was coded (with the use of a bar-code) and the important intersection points with other building compo-nents were mentioned.

Afterwards, at the construction site, the place-ment of each component, recognized from the bar-code, were directly given by the three-di-mensional model (CATIA). Special preview laser equipment, directly connected to the digital model, was scanning the under construction building and was ensuring the accurate place-ment of all parts, as was defined by the model. Annette LeCuyer mentions that “these tech-niques, despite being relatively new in building construction, constitute common practice in aeronautics and ship-building.”

Furthermore, the information exported from a three-dimensional model, as far as the geom-etry is concerned, could be given as inputs for controlling the movement of an industrial ro-botic arm that could execute a series of actions in a construction site. In Japan, a series of robot ic devices have been developed specialized in transporting and assembling parts.

4.[ Digital design fabrication/DDF ]

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4.1.Definition: Digital Design Fabrication

Digital design fabrication, a term that has been extensively analyzed by Larry Sass (Sass, L., 2006) professor in architectural department of MIT, could comprise all the information mentioned so far. DDF aims to compose the flexibility of traditional design on paper, the accuracy and modeling ability of digital design and the direct con-nection with construction that digital fabrication offers. The goal is to create an environment that will support design – through interaction – with the production of structural elements and physical models. This will be sup-ported by being in direct contact with the flexibility, accuracy and manipulation ability of the information that the describing objects’ environments have. The combination of two opposing characteristics is being provided; on the one hand the necessary freedom and flexibility of the design process and on the other hand the accuracy and ability of a detailed described fabrication process that characterize CAD-CAM devices

4.2.The notion of digital design fabrication:Design models,Design in-formation models,Building Information Models (BIM)

DDF process produces two model types. On the one hand design models exist as one and only object. On the other hand design information models exist as an object constituted by parts that follow construction restrictions. In mass-ing models of early design phases one studies the arrangement of volumes in relation to the space requirements implied by a given brief. They are described by volumes or surfaces in CAD and are quickly produced by rapid proto-typing machines. These small in size models are valid for volumetric and morphological assump-tions. They do not follow a specific construction method, nor are described by any material. The second model type refers to the assembly of the different parts. Depending on their design level, they are characterized by variety in the degree of detail and the construction information they carry. Design information models consti-tute an abstract way to describe buildings as design products (Eastman, 1999). In this model type a degree of complexity starts to arise, as they could be shaped from many materials and have relatively big size. These models offer the possibility of evaluating design and construction process of some details, while they could pro-vide a sense of the interior space. This depends on their scale that could vary according to the design phase. They cover all the phases between the first schematic design models and the final model as well. The developement of such digital models is quite time consuming as does their production from RP machines. An advantage of DDF is its ability to provide models in all in-between stages, from the early design phases until the BIM (building information model). The latter concentrate on representing a design project in 1:1 scale, without causing

important changes in model’s geometry, only adding on that more information. The goal of this method is to record construction information from data bases on a three-dimensional object of design information that sequentially ends up being the construction model. With the term structural unit we refer to any part that structurally participates to a building, such as for example a brick. Alternatively the term component is used, which is closer to mechani-cal engineering. This is not necessarily out of context as it is possible in the near future the construction of a building to be considered simi-lar to a machine assembly. The term component is most commonly used to refer to a structural unit. The design of structural units is a signifi-cant parameter of DDF that is also connected to the assembly properties. This lies in the fact that the use of rapid prototyping machines is possible to produce structural elements that are directly related to design and thus customized, as well as multifunctional. Therefore, the aim is to model and construct “smarter,” parametrically controlled structural units that can offer multiple ways of i.e connecting. Furthermore, it is es-sential for these units to have the same global behavior, but not necessarily same local cross-section or form. The goal for these units is to be able to respond to the construction restrictions that the available technology (CAM) and as-sembly methods provided, while they could be unique for each project. This comes as a con-sequence of the introduction of CNC machines, as it is equally easy and economically efficient to produce 1000 unique components and 1000 identical ones. The possibility of unique structural component mass production re-introduced the term mass customization in the field of architec-tural design and construction.

image 35: dome studyscaled model of structural compo-nents assembly (Saas L)

image 34: dome study-3d printed building components, (Saas L)

.component design/ σχεδιασμός δομικών μονάδων/

Με τον όρο δομική μονάδα αναφερόμαστε σε οποιοδήποτε στοιχείο συμμετέχει δομικά σε ένα κτίριο όπως για παράδειγμα ένα τούβλο. Εναλλακτικά, χρησιμοποιείται και ο όρος εξάρτημα ο οποίος βέβαια μας παραπέμπει στην μηχανολογία. Αυτό δεν είναι απαραίτητα άτοπο αν αναλογιστεί κανείς πως δεν αποκλείεται στο κοντινό μέλλον η κατασκευή ενός κτιρίου να θεωρείται εφάμιλλη με τη συναρμολόγηση μιας μηχανής. Ήδη στην ξένη βιβλιογραφία με τον όρο του εξαρτήματος/compo-nent αναφέρονται και σε αυτόν της δομικής μονάδας. Ο σχεδιασμός δομικών μονάδων είναι μια σοβαρή παράμετρος του DDF που συνδέεται και με την διαδικασία της συναρμολόγησης/ assembly (εικόνες 35,36). Αυτό έγκειται στο γεγονός πως με την χρήση συσκευών rapid prototyping είναι η δυνατή η παραγωγή δομικών στοιχειών, τα οποία δεν είναι τυποποιημένα, σχετίζονται άμεσα με τον σχεδιασμό και μπορούν εν δυνάμει να πραγματοποιήσουν παραπάνω από μια λειτουργιά.

Επιδιώκεται λοιπόν η κατασκευή «εξυπνότερων» τούβλων, παραμετρικά ελεγχόμενων, τα οποία έχουν την ικανότητα όχι μόνο να στοιβάζονται, ενώ δεν είναι απαραίτητο να έχουν την ίδια διατομή ή μορφή παρά μόνο την ίδια συμπεριφορά. Στόχος είναι τα στοιχεία αυτά να ανταποκρίνονται στους κατασκευαστικούς περιορισμούς που επιβάλει η διαθέσιμη τεχνολογία (CAM) και μέθοδοι συναρμολόγησης τους ενώ μπορεί να είναι μοναδικά για κάθε μελέτη. Αυτό έγκειται στο γεγονός ότι είναι το ίδιο εύκολο και οικονομικά αποδοτικό για ένα μηχάνημα CNC να παράγει 1000 μοναδικά εξαρτήματα όσο και 1000 ταυτόσημα. Η δυνατότητα μαζικής παραγωγής μοναδικών δομικών στοιχείων, διαφορετικών μεταξύ τους, εισήγαγε τον όρο του mass customization στο πεδίο του αρχιτεκτονικού σχεδιασμού και παραγωγής.

4.3.Component design

With the term structural unit we refer to any part that structurally participates to a building, such as for example a brick. Alternatively the term component is used, which is closer to mechanical engineering. This is not necessarily out of context as it is possible in the near future the con-struction of a building to be consider similar to a machine assembly. In foreign bibliography, they already use the term component to refer to a structural unit. The design of structural units is a significant parameter of DDF that is also connected to the assembly properties. This lies in the fact that the use of rapid prototyping ma-chines is possible to produce structural elements that are not customized, are directly related to design and could perform more than one function. Therefore, the aim is to construct “smarter,” parametrically controlled bricks that have more abilities than being piled up. Furthermore, it is essential for these bricks/units to have the same behavior, but not necessarily the same cross-section or form. The goal for these units is to be able to respond to the con-struction restrictions that the available technology (CAM) and assembly methods provide, while they could be unique for each project. This comes as a result of the fact that for a CNC machine is equally easy and economically efficient to produce 1000 unique components and 1000 alike. The possibility of unique structural component mass production introduced the term mass customization in the field of architectural design and construction.

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4.4.Mass-customization VS mass-production

The ability to mass-produce one-off, highly differenti-ated building component with the same facility as standardized parts, introduced the notion of “Mass customization” into bulding design and production.Mass production, the Post-Fordian paradigm for the economy of the 21st century ,was defined by Joseph Pine as the mass production of individually-customised goods and services, thus offering a tremendous increase in variety and customization without corresponding increase in costs (Kolarevic, 2003). Under this light, mass customization offers not only a remarkable increase in variety, but also a possibility of personalization without increasing the production cost. The term was established by Stan Davis in Future Perfect (Davis, 1987), while Alvin Toffler perceived it as a technological capability in 1970 (Kolarevic, 2003).

Modernism principles of the 20th century mostly followed fordism model of industrial production and joined construction production with concepts such as standardization, prefabrication and in situ place-ment. The logic of industrial production imposed geometric simplicity over complexity and repetitive use of low cost mass produced components. The existing characteristics of this production type have been altered as digital controlled devices can pro-duce unique and complex in shape components, the cost of which remains affordable. In other words, variety does not stand opposite

economic efficiency. It is therefore obvious that mass customization is appropriate for construction pro-duction, as most of the buildings could be consid-ered as original products that are hardly mass pro-duced. Thus in a typologically simple building, such as an office tower, design coding and parameterizing hides a retaliation, that of getting a wide range of design solutions by making small changes in design. For example, it is possible to produce structural elements, which could range depending on the local conditions and the forces that they curry. Digital design mass customization initiates a new se-quential concept in architecture that could be based upon the spatial variety and difference. Modern aesthetics considered residence as a constructed housing machine, which through mass customiza-tion could make design a privilege of the people and not only of the elite. The modern translation of this concept does not impose a homogenous condition nor establishes a prototype that covers all situations (one size fits all), but suggests the uniqueness and difference that could be accomplished through the digitally controlled variety and the at will parameter-ization. We should keep in mind that this condition, to a certain level, has been applied. Nike, for ex-ample, through its Nike ID project offers the con-sumer the possibility of selecting color and material on specific products in the same price with the rest of its products. We may soon have the possibility of altering the design or even creating a personal one.

00001N005 G54 G90 S400N01 G00 X1 Y1N015 G43 H01 Z1 MN020 G01 Z-125 F3.5N025G00 Z-1N030 X2.N035 G01 Z-1 M09N040 G00 Z-1 Z0N050 M30N055 M35N060 G00 Z-2 M08N065 G55 G95 S450N070G00 Z-1N0G00 Z-1

image 38: part of a code controlling the direction of a CNC (G-Code) and analysis of the motion workflow of an RP device.

.περιγραφή της κατασκευής

Ένα ακόμη βασικό στοιχείο του DDF, είναι το γεγονός πως η άμεση σύνδεση του σχεδιασμού με την παραγωγή π.χ. εξαρτημάτων εισάγει άμεσα την παράμετρο της αποτελεσματικότητας. Οι τεχνικές παραγωγής και οι μέθοδοι λειτουργίας των μηχανημάτων αποκτούν μια σημαντική θέση στον σχεδιασμό αφού εξασφαλίζουν την καλύτερη ροή των εργασιών. Ιδιαίτερα σημαντικός κρίνεται φυσικά και ο τρόπος περιγραφής του σχεδιασμού, καθώς η μετάφραση του μοντέλου σε κώδικα G εισάγεται ως δεδομένο για την υλοποίηση από τα μηχανήματα CNC(εικόνα 39). Έτσι μια συσκευή κοπής laser, απαιτεί την δυσδιάστατη περιγραφή μιας τρισδιάστατης γεωμετρικής φόρμας, ενώ μια συσκευή additive fabrication απαιτεί την τρισδιάστατη περιγραφή του κελύφους και μόνο μιας γεωμετρικής φόρμας. Η περιγραφή αυτή εκτός των γεωμετρικών δεδομένων περιέχει και το μονοπάτι που θα ακολουθήσει η κεφαλή του μηχανήματος, πράγμα που προσθέτει άλλον έναν παράγοντα κατά την φάση του σχεδιασμού.

.η παράμετρος της κλίμακας

Πριν την εισαγωγή των τεχνολογιών των συσκευών rapid prototyping και CAD-CAM, υπήρχε ένα χάσμα στα ψηφιακά σχεδιαζόμενα μοντέλα τα οποία πρακτικά δεν είχανε κλίμακα. Έτσι πολλές φορές οι αρχιτέκτονες αντιμετώπιζαν το πρόβλημα της προσαρμογής του ψηφιακού μοντέλου στην πραγματικότητα. Με την εισαγωγή του DDF, επιβάλλεται ο άμεσα συσχετιζόμενος με την υλική του αναπαράσταση σχεδιασμός. Αυτό σημαίνει πως το ψηφιακό μοντέλο εμπεριέχει ως ένα βαθμό υλικούς περιορισμούς, καθώς στην περίπτωσή που αυτό δεν συμβαίνει δεν είναι δυνατή ούτε η ψηφιακή παραγωγή του. Ο σχεδιαστής έχοντας γνώση των ορίων του (διαθέσιμου) μηχανήματος ψηφιακής κατασκευής φροντίζει αυτό που σχεδιάζει να είναι προσαρμοσμένο ανάλογα. Για παράδειγμα θα αναλύσει μια τρισδιάστατη επιφάνεια σε panel τέτοιων διαστάσεων ώστε να μπορούν να επεξεργαστούν από ένα laser cutter, ή θα σχεδιάσει ένα δομικό στοιχείο το οποίο θα μπορεί τυπωθεί από μια συσκευή στερεολιθογραφίας/ SLA device για να αξιολογηθεί. Σε πιο πρακτικό επίπεδο τα design information models παράγονται κατά κύριο λόγο από συσκευές rapid prototyping ενώ τα building informa-tion models από μηχανήματα CNC.

4.4.The parameter of scale/ Scale-ability

Prior to the introduction of rapid prototyping and CAD-CAM technologies, during the first years of the introduction of digital desing tools in architecture, there was a gap in digitally de-signed models, which practically were charac-terized by the absence of scale and materiality. Therefore, architects many times confronted the problem of adjusting the digital model to reality. During DDF process, a direct relation between design and materialization is necessary. That means that the digital model embodies to an extend materialization restrictions, which deter-mine its digital production. The designer takes into consideration the restrictions of the avail-able digital fabrication machine and makes sure that his/her design is adjusted to it.

For instnace, he/she will analyze a three-di-mensional surface in panels, the dimensions of which could be processed by a laser-cutter, or will design a structural element that could be printed by an SLA 3d printer so as to be able to be evaluated according to structural perfo-mance. In a practical level rapid prototyping machines produce design information models

(DIM), while CNC machines produce building information(BIM) models.

4.5.Construction description

Another basic DDF characteristic is the fact that the direct connection of design with production (i.e. components) introduces immediately the parameter of effectiveness. Machines produc-tion techniques and function methods gain an important position in design as they ensure a better work flow. Furthermore, the method of design description is also extremely important, as model’s translation in G code is introduced as input for its materialization from CNC ma-chines. Thus, a laser-cutter machine demands a two-dimensional description of a three-dimen-sional geometric form, while an additive fabri-cation machine demands a three-dimensional description of the shell of only one geometric form. This description apart from the geometric inputs involves also the path that the machine’s head will follow, which constitutes another de-sign factor.

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imagw 36: multiple 3d prints of a design procedure for a concert hall ( Gehry Architects)

image 37: examples of 3d prints in different scales and with varying degree of details

5.[case studies]

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image 39: Fabrication operator (Pantazis E.) image 40: photo from Chesa Futura (Foster Associates) with the village St Moritz in the background

image 42: photos of Tesselion (Skylar Tibbits)

In the next chapter, we will provide a more specific view of DDF’s application in architecture, through a selec-tive reference to realized and experimental projects. The selected examples vary in program, scale, budget and complexity; so as to demonstrate the range of the field they could be applied. The first two analyze the use of design operators in design process and study their advantages. The third one refers to an overall use of DDF in design.

The first example is theoretical; it is a student master project in computation and architecture, which is directly related to the theoretical part of design operators and computation that was analyzed in the previous chapters. The second one, is an example of information managing; it has to do with an installation, the whole design and construction phase of which is described day by day through a blog from the chief architects. It refers to the personalization of a tool provided by a three-dimensional design program for the production of the desired result and also to the continuous amelioration of the designed object through models and con-stant controls. Lastly, the third example presents the whole design and construction process of a residential building in Switzerland, after its completion. Chief-architect’s comments in relation to the description tran-script of the project process outline the image of DDF’s application in real practice conditions.

5.1.Rapid prototyping and fabrication operator/M. Dritsas, E. Pantazis

This project constitutes an example of a general design operator creation that performs a process of direct prototyping. It has to do with a code capable of reproducing all necessary design information for the expression of every arbitrary surface to physical space. It was created by the author in rhinoscript and was based on previous work done by S. Drit-sas, master student at MIT. The goal is two-fold; to confront complexity that the process of fabricating a digital designed surface model may create and to compress the time needed for the completion of this process. It constitutes an outstanding mecha-nism of negotiation between physical and digital design. The presented design problem, which is the fabrication of a double curved surface out of planar elements for the creation of a model as well as a design artefacts, helps us understand the phases of an operator development, the reasons that lead to its development and the importance of computa-tion for design.

The goal was to describe all the necessary steps needed in order to produce one single model from a surface, and afterwards by changing the constant constraints of the process into controlling parame-ters to be able to repeat the sequence with any ge-neric initial input in order to create different design outcomes based on a given brief. This is a typical implementation process of any automation favored operator: map down all actions under fixed-static conditions, produce a working program and then figure out where are potentials of parameterizing thus generalizing the process exist (Dritsas, S., 2003). This constitutes a classic way of dealing with every operator that is under automation :

a) record every movement under specific condi-tions, b) produce a work program, explore the existence of parametric possibilities and in that way general-ize specific parts of it.

An interesting ability of this way of coding a pro-cess is that it allows the direct location of all pos-sible parametric points. All numeric information, for example, become immediately visible and could be parameterized.

This specific code takes as input every possible surface and a sequence of parameters. By analyz-ing the surface in curves that describe it in two vertical directions (isoparametric curves) it creates a curvy grid made of interconnected side parts over the surface. Then it reproduces the developement of its parts in a two-dimensional surface. These parts are sequentially numbered, coded by color and grouped. This process produces a design description suitable for further development with a two-dimensional construction machine that is every possible CNC machine. The completion of this process takes few minutes, depending on the machine’s power. Executing the same process by hand demands many hours. Therefore the advan-tage of selecting the coded process is based on time compression. By studying this coded process more carefully, it becomes obvious that the computer executes a se-ries of geometrical computations, in a non Euclid-ian surface, that a typical user could not execute without the aid of the computer. This difficulty is not the outcome of the “objective fact” that the user

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image 43: digital models, coded outputs coming from a given surface with diferrent degrees of subdivision and marking of the intersections (knot).

is unable to copy the machine’s behavior. In every case the nature of automation secures that whatever the machine executes is the outcome of a coded behavior provided by the user. The key point of this process is the accuracy and stability of the results guaranteed by the machine, given an intact coded process.

Furthermore, apart some first technical advantages that such a technique ensures, such mechanisms cause interesting design process effects. For ex-ample, the fact that the digital design result, being trapped in its two-dimensional representation, could constitute a physical model for evaluation is obvi-ously a more important result. Despite the fact that this evaluation is partial, as the model constitutes another design representation, its physical status allows a more tangible evaluation of the design concepts. The process of exploring possible ways to translate design in physical space is provocative, expressive and enables a richer design product.

The ability of reproducing multiple versions of a design form develops the traditional idea of design evaluation through different simulations. Although the difference is quantitative, one may produce many models of the different design phases, it ends up being qualitative. The classic evaluation process and judgment of design alternatives is based on a finite group of produced representations, sketches, models, orthogonal projections, which are evaluated in comparison. Thus, we are used to select a small number of products, through a sequence, and to imagine the intermediate ones. Technically speaking, this is called interference. The process restrictions

are assigned to practical obstacles. For example, it is easy to imagine the in-between situations of two conditions, but it becomes impossible when these conditions increase. The revolution of the computa-tional processes development lies in their ability to selectively produce samples of infinite combinations based on fractions of a series of possibilities that interject between multiple attractors.

Although this example is relatively restricted, it provides a lot of information on the ways one could handle such processes. Scale parameter is the next issue that comes on surface; a similar process, accordingly adjusted was used for furniture de-sign production. In this updated application many actual factors were taken into consideration in the implementation of the design, such as for example the torsion possibility of the side elements that was “frozen” during the development process. Another arbitrary manipulation was the subdivision of the NURBS surface topology on a grid through the sim-plified use of the parameterization that every design environment provides. Based on the gained experi-ence from the physical models this was enhanced in the actual designs. For the time being, one could argue that factors such as the above or the material properties could be embodied in the process and could provide more efficient results, either by solv-ing the problems that may arise or by notifying the user that the solution is impossible. However, given the restriced programming skills, that might also (for simpler applications) be too complicated to describe computationally that doing it intuitively.

Παρότι το πείραμα αυτό είναι σχετικά περιορισμένο, προσφέρει πολλή τροφή για τον χειρισμό τέτοιων διαδικασιών. Η παράμετρος της κλίμακας είναι το επόμενο θέμα που αναδύεται: μπορεί η ίδια διαδικασία να χρησιμοποιηθεί για την πραγματική παραγωγή του σχεδίου. Στην συγκεκριμένη εφαρμογή πολλοί πραγματικοί παράγοντες αφέθηκαν κατά μέρος, όπως για παράδειγμα η πιθανότητα στρέψης των πλευρικών στοιχείων. Αυτό συνεπάγεται πώς το πρόπλασμά μπορεί να κατασκευαστεί μόνο με κάποιο «ελαστικό» υλικό όπως χαρτόνι, χαρτί, ή ένα λεπτό φύλλο μετάλλου. Η καναβική υποδιαίρεση της τοπολογίας μιας NURBS επιφάνειας (εικόνα 45) αποτέλεσε έναν επίσης αυθαίρετο χειρισμό με την απλοποιητική χρήση της κατεξοχήν παραμετροποίησης που κάνει το οποιοδήποτε σχεδιαστι-κό περιβάλλον. Η αρχική αφελής εκτέλεση πέρασε χωρίς εμπόδιο ανάμεσα από πολλά ρεαλιστικά προβλήματα. Για την ώρα, μπορεί να ειπωθεί πως παράγοντές όπως το υλικό, μπορούν να ενσωματωθούν στην πορεία της διαδικασίας και να δώσουν πιο αποδοτικά αποτελέσματα, είτε λύνοντας τα προβλήματα που θα προκύψουν είτε ειδοποιώντας τον χρήστη πως η λύση είναι αδύνατη.

Η συγκεκριμένη εφαρμογή υπέδειξε πως μια διαδικασία κωδικοποιημένη κατά αυτόν τον τρόπο, μπορεί να είναι πολύ ευέλικτη, καθώς μπορεί αυξητικά να οργανώνεται με βήματα από το γενικό στο ειδικό. Με το που ένας νέος παράγοντας αποκαλύπτεται, ο κώδικάς πρέπει απλά να αναπροσαρμοστεί παρά να ξαναγραφεί εξ αρχής, έτσι ώστε (παραμετρικά) να συμπεριλάβει την νέα βάση δεδομένων. Για τον λόγο αυτό, οι ίδιες πυρηνικές διαδικασίες μπορούν να γενικευθούν έτσι ώστε να συνεργάζονται με την παραγωγή, τη διαθέσιμη τεχνολογία και τα επιθυμητά υλικά, τα οποία εισέρχονται στη διαδικασία ως βάσεις δεδομένων. Συνεπώς, η μόνη ουσιαστική διαφορά είναι το μέγεθος της βάσης πληροφοριών που πρέπει να κωδικοποιηθεί, ο βαθμός δηλαδή λεπτομέρειας που θέλουμε κάθε φορά να εκπληρώνει ο κώδικας. Εδώ γίνεται προφανής η βαρύνουσα σημασία που αποκτά ο «σχεδιασμός του σχεδιασμού» σε μια τέτοια διαδικασία, όπως προηγούμενα αναφέρθηκε. Αυτός καθορίζει σε μεγάλο βαθμό και την ευελιξία της

εικόνα 44(επάνω): μοντέλο επιπεδοποίησης του κόμβου και αναπαραγωγή του στον χώροεικόνα 45(αριστερά): καθορίσμός των σημείων τομής των isoparametric curves και παραμετροποίηση τους για έλεγχο επί της ανάλυσης της επιφανείας.εικόνα 46(δεξιά): α,β)όλα τα στοιχεία της μακέτας κομμένα με laser, γ,δ,ε)συναρμολόγηση των στοιχείων και στ) διαφορετικές εκδοχές ( με βάση τον βαθμό ανάλυσης της επιφάνειας)

image 44 (above): model for flattening the interlocking point του στον χώροimage 45(left): defining the cross section points of the isoparametric curves and their paramtrization for control over the analysis of the surface.image 46(right): a,b)Laser cut panels with all the components nested c,d,e)assembly of all the components, and f) alternative de-sign outcome depending on the subdivision degrees of the surface.

This application both in smaller scale models as well as in 1:1 design objects aimed to show that a coded process could be very flexible, as it could be orga-nized in sequential steps from general to specific. Whenever a new factor is revealed, the code has to readjust itself rather than rewrite itself, so as to para-metrically include the new database. For that reason the same core processes could be generalized, so as to cooperate with the production, the available technology and the desired materials that are introduced into the process as databases. Therefore the only substantial difference is the data-base’s size that has to be coded, that is the degree of detail that we want the code to fulfill.

At this point, it becomes obvious that the “design of design” turns out to be a really important factor in such a process, a fact that was also mentioned in a previous chapter. It is the factor that determines to a great extent the flexibility of the process. This example serves as a good excuse to discuss another characteristic of digital design. Until now we referred to the ability of digital design to “carry” construction information even from the early design phases, but we have never discussed the segmentation characteristics and abilities that it offers.

By that, we imply the total ignorance of some spe-cific factors of a problem in combination with the ab-straction of the medium, to the extent that it allows the examination of real problems without having to deal with the initial and in-between frictions with it. For a certain period of time, the model’s materiality was not an obstacle for the code’s execution. On the contrary, it provided the possibility of reflection and production of specific tangible results. What fol-lowed next was the realization of the next steps that were necessary for the specification of the results. S. Dritsas mentions:“By the same means of scripting it is possible to in-corporate engineering information either by encoding some partial simulation models or by merely plug-ging-in and adapting a more credible open and pub-lic engineering code-library. The meaning of hacking in these terms refers to the potential accessible back-doors that the computation opens to other fields of knowledge to designers and to the possibili-ties for more information-dense designs.”(Dritsas S., 2003)

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A level of abstraction between intentions and real considerations/conditions was always a very cre-ative design factor. The difference in digital world is that allows many back and forth in this process. With scripting is possible the direct embodiment of mechanic or static factors in design, either by cod-ing some simulation models or by connecting the application with a reliable and open to public library of equivalent codes (of mechanics and statics). This example although not reaching that amount of pro-gramming complexity, proves that such embodiment of “realistic factors” can be introduced by the de-signer ‘s intuition or the fabricator’s experience in smaller scale projects whereas when nthe complex-ity rises they could be introduced computationallly.Under this light, the concept of segmentation refers to possible alternative accesses from other fields that computation opens to architects and up until our days were segregated.

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images 46 (above left): photo of a bookselves design ap-plicationimage 47 (above right): photo of a coffee table design ap-plicationimage48 (opposite): photo of a conference table design applicationimage 49 (above): photo of a light fixture design application

5.2.Τesselion/ Philadelphia University Arch./ Skylar Tibbits/tutore: Fornes M., Yancone A.

“Recently the development of planar quadrilateral meshes has become a strong interest in the architectural community due to their potential ease for constructing complex surfaces. The project responds to this prob-lem and proposes a method for flat panelization of free form surfaces which provides large scale, efficient and economic construction from flat sheet material.” (www.tesselion.wordpress.com)

Tesselion is an installation placed at the depart-ment of architecture of Philadelphia University in June 2008. It is characterized by a relatively simple program that includes the roofing of a space and the creation of a seating place for its users. It’s a project that was based on the adjustment of a clas-sic three-dimensional design program command (subdivide surface) for the development of a special design operator. This design operator manipulates the subdivision of complex, non regular surfaces in a panel system directly fabricated by a CNC ma-chine. The aim is to simplify the fabrication of such forms, of relative large scale, and the creation of a spatial environment that is parameterized based on factors such as natural light and its programmatic adjustment. The form of the space emerges from the manipulation of these factors. Each panel could be unique due to the possibility of its digital production, while the development of coded parametric relation-ships allow for an emerging structural efficiency. The

optimization of the design result was based on mate-rial saving and construction efficiency. In this example, one could clearly see that param-eterization offered by digital design serves design’s readjustment depending on new inputs, while its connection to fabrication allows for multiple back and forth in a relationship in which simultaneously one feeds the other and vice versa. Through the “blog” that the architects created one could observe not only the elaboration of the project, but also the interesting design process.

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image 50: photo (detail) Tesselion’s structure (Skylar Tibbits)

5.2.1.Research

Initially, after the definition of the program, architects decided to study a series of knots based on some criteria, such as:a) torsion resistance in two axis, b) panels dissociation/removal resistance, c) manipulation of construction’s structural integrity and certification of the necessary conditions for the construction to “curry” itself and d) production will be realized with a subtractive fabri-cation CNC three-axis machine, or with a laser-cutter machine. These machines work with planar sheet material of specific dimensions. At the same time, a research on material was conducted based on the following criteria: weight/density, cost, and resistance. Alumi-num was founded to be the most appropriate one. The size of its cross-section was later decided, after being controlled on a physical model.

5.2.2.Form

The installation’s form was based on three essen-tial elements: a specific space in the university of Philadelpheia, where the installation was going to be placed, a given program and natural lighting. In the first stages, the range of tesselion’s capabilities on analyzing a surface was tested. According to the researchers the criteria to select a surface for analy-sis are subject to economic and time restrictions and also to certain small scale structural problems that may arise. Apart from that practically every surface could be analyzed with the design opera-tor tesselion. This design operator is parameterized to the extent of surface analysis that is the number of panels on which a surface could be analyzed to. Grater analysis means greater approximation of the non regular geometry and as a result more panels. This parameter was an important factor in the spe-cific project due to its financial effects. Apart from the surface analysis to individual panels, emphasis was given to the opening’s research. Their form and placement was based on environmental conditions (natural light) and also on simulations that were con-ducted in a digital environment.

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images 51-54: renderings from design studies of the installation (above)image 55: rendering of the final proposal.(left page)image56: drawing of an unrolled panel and 2-3 as-sembly strategiesimage 57: construction draw-ing of connection with the ground image (above right)58: foundation detail(above left)

image 59 (from above to below): design& construction process a) renders from different design alternatives. b) renders of different possible connectionsc) force distribution (loads) diagrams and models of the connec-tion point d) cardboard scaled model of the installation e) cutouts and assembled sheet metal mock-ups in 1:1 scale.f) on site construction

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image 60: photo of the installation’s upper part. image 61: photo overlooking the structure.

5.2.3.Design timeline

During the project developement , which was not linear, multiple studies were designed and tested that had to do with the way the panels were connected and the form of their connections/knots. The design was tested both in physical and digital space. As time was passing the design model was informed, while after being tested through physical models and digital simu-lations (FEA control and torsion, bending, link controls) panels’ connections changed more than one time. The solution of having one panel with a folding blade that will function at the same time as a connection/knot was preferred to the use of an individual element as a connection/knot. Part of the construction was tested three times for errors both at scale 1:1 (assembly of 6 panels) and through physical models of smaller scale. The creation of each model was followed by a reflection on design; record of its weak points, research of possible alter-native solutions and direct update of the code with new data. This update has to do not only with design issues, such as the change of the connection/knot but also with practical issues, such as panel numbering and their appropriate placement to the available mate-rial panels, so as to save material. The development of the project study took three months. Through the blog one could follow day by day in detail the whole con-structive process of updating the working model, as well as the continuous exchange of files and opinions between constructors and designers.

5.2.4.Realization

After 3 months of continuous controls and attempts to optimize the design result the research team decided that the design was in a satisfactory level. For its fab-rication they decided to use white aluminum of a 2mm cross-section. A total of 187 panels of a 20.3x10.2 cross-section cm were send to a laser cutter to be cut. A necessary work at the location space involved the construction of the foundation that was made of me-tallic sticks and concrete, upon which the panels were assembled. The assembly of the construction, which involved panels’ folding and bolding, took seven days for one person who was working twelve hours per day.

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5.3.Chesa futura/ St. Moritz/ Switzerland/ Hugh Whitehead/ Foster and associates

The project is a residential building in the tourist resort of St Moritz at Engadin valley at Switzerland Alps. The specific project combines the use of complex geometry and current construction technology It is an example that was studied and constructed by digital media. Architect’s reflection on the project, after its completion, makes clear the advantages of the specific working method. Furthermore, one could understand how a not very abnormal project of that scale could be materialized to the last detail.

The site is placed 1800m above sea’s altitude. The project is the amalgam of design tools of high tech-nology and local traditional construction techniques that creates an environmental friendly building. It combines the application of environmental friendly traditional wood construction onto an innovative, pumpkin shape form. As Hugh Whitehead mentions

“The bulding is raised off the ground on eight legs and has an unusual pumpkin-like form. This is a creative repsonse to the site, the local weather con-ditions and the planning regulations. The site has a height restriction of 15.5 m above its sloping con-tours. If the building were built directly on its sloping site, the first two levels would not have view over the existing buildings. Elevating the building provides views over the lake for all apratments and main-tains the view of the village from the road behind the building. Raised buildings have a long architec-tural tradition in Switzerland-where snow lies on the

ground for many months of the year-avoiding the danger of wood rotting due to prolonged exposure to moisture.” (Kolarevic B., 2003)

By sculpting the building into a rounded form, it responds the planning regulations. A conventional rectilinear building would protrude over the specified height.the limit. The decision not to introduce a use at the groundfloor as well as the first flooBecause the ground and first floor are not utilized, the three elevated stories are widened to achieve the overall floor area, but do not appear bulky due to the building’s rounded form. The curved form allows win-dows to wrap around the facade providing panoramic views of the town and the lake.

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image 62: photo of the Chesa Futura residential building 5 years after its completion

image 63: photo of the Chesa Futura pilotis

5.3.1.Form development/finding

The curve-like form was the result of the possibilities and the town planning restrictions of the site. The initial sketches and drawings were interpreted and formed in a three dimensional parametric model, which was then analyzed by the team in sub-reference-files so and thus the changes could happen in both directions (from the sub-files to the central file and vice versa). A para-metric version of the section changed many times in several months, while at the same time it was informed by other design factors (mechanical, electronic etc). The restrictions were such that a 2 degree rotation in design signified a 50m2 loss in plan, while a 2 degree rotation in section meant a 10cm decrease of the inter-nal height of every level.

5.3.2.Construction strategy

Due to the particularly hard climate conditions in the area during winter, construction work could carry out only six months per year. Thus, project’s timetable anticipated the construction of a metal grid with a concrete slab and then the pre-creation of the whole shell during winter, when it was impossible to work on site. Then during spring time, it would be possible to install the framework, the uplifted base, the columns and the roof and thus the shell could be completed and foreclosed before winter. Afterwards, the project would continue with interior work. This plan was the project’s construction strategy, which meant that the precise division of the work parts was of critical importance.

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image 64: parametric cross section of the buildingimage 65: diagrams of the de-velopement and control of the skin and the building’s overall formimage 66: perspective section ans rendering of the interiorimage 67: stuctural scaled model of the building.(from left to right)

image 68: exterior view of the building, handmade production of the wooden roof tiles from a local carpenter, digital fabrication of the structural beams

5.3.3.Database management strategy

For rational design organization, the idea of comparing plan with section was explored in an eminently design way, reproducing nonetheless possible construction solutions with the use of small applications, known as macros. These macros operated as a “ruler” that was controlled by a polar coordination system. The ruler scanned plan’s sectors and lists measurements, which were then projected onto the corresponding lines in section. Subsequently, it produced a series of param-eters, which were embodied in a based on restrictions wall section. As a result the wall was obliged to adjust itself to the corresponding shell positions. The specific macro had a dual function: it could either produce a solid model of the shell surface, with the connected parts of its structural framework, or to produce a table with multiple drawings that could be used for further detail drawings production. As the project was devel-oping, every member of the group was responsible for a different parameter set that related to the thickness of the used materials. One group member could

work on the roof, another one was responsible for the structural framework, a third-one dealt with the zone of shell-columns, surface-layering and fire protection, while a fourth-one controlled the openings and window details. Having access to the same parametric file, allowed the group not only to respond to each design direction but also to coordinate the project’s process. At the same time every sub-group was making the necessary changes as a response to other sub-group changes.

The whole digital model geometry was based on circu-lar arcs. The programming of the pre-construction de-manded a digital model that could lead advanced CNC machines to a German factory, in precise mechanical durability. The chief-architect mentions that “to suc-cessfully use these machines, we should understand the modeling process in relation to its mathematical translation. Although the surface has characteristics of a free form curve, it is analyzed in individual normal

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image 69: perspective cross section of the openings image 70: perspective section of the building’s interior

surfaces that have their routes in circular arcs that perfectly osculate.”

The analyzed surfaces are ideal for the process of solid core modeling, as the software could directly compute the counterbalances and produce accurate and clear results, a fact that is very important during an intense design activity. The ability of producing direct and reli-able computation without having software (CAD) errors allowed the continuous exchange of digital models with Swiss project engineers and German construc-tors (Amann). Design group’s decision to rationalize the shell-surface, by analyzing it in circular arcs, provided a degree of control that helped not only to simplify but also to solve many design and construction problems. The limited command range (macros) that were devel-oped could calculate all circular arcs, on the basis of construction prescriptions and then could place them in space, by reproducing automatically the shell, the framework and all individual three-dimensional parts, based on the parametric values of each relocation. The result was a precisely defined shell, which constituted

the surface that was given to the engineers to work on and solve.

Hugh Whitehead mentions that “At this point we made a commitment to make no further alterations to the de-sign surface ,although offsets were continually varied throughout the year as the project evolved. We could locate any component by choosing a position on the polar grid, creating a plane, and intersecting with the design surface to determine the radial offset for placing the component. In addition to being able to accurately model and place components in space, we could gen-erate a matrix of sections, drawn for each rib position and thus produce templates for all shop drawings”

When the plan and section had to be changed, even at the latest project phases, the group could reproduce the shell-surface in a cohesive and reliable way. This design process, based on some programming materi-als, had been developed to the extent that it was a more spiral rather than a linear process. The freedom of exploring multiple alterations of a design was proved

to be the key point of optimization.

5.3.4.Assembly strategy

Hugh Whitehead mentions, ” In the Foster studio, most of the key design descisions are still made from the study of physical models. In fact, the CAD system was introduced initially to the studio to pro-vide shop drawings for our model makers.”

With the use of digital technology a project could start from three-dimensional digital models and then send in the model lab to be fabricated with CNC ma-chine. There is a constant dialogue between draw-ings, digital models and physical models. A typical project meeting includes all possible media – sketch-es, digital models, renders, physical models made out with CNC as well as rough physical models.

Chesa Futura’s next model generation was based on actual structural elements and was designed in a way to exactly control building’s assembly process, as the construction firm Arup envisioned and the Swiss technical company Toscano developed. This model contained everything, starting with the metal-lic framework with the uplifted lower part, the con-crete slab, the side carrier parts and the columns of C profile of the front balconies and finally the circular roof disk. This corresponds to the initial level that was used to define the surface, which was signified by a slopped rut that indicated material change from the side wall to the roof. All windows are similar and double, so as to be efficient in the extreme climate conditions. The openings on every window façade are different and made individually, but the financial profit of using one type of window-frame is a lot higher.

Every digital model generation was leading to the next physical model generation, as a greater degree of detail was explored. At this point they had to study the control technique of the wooden surface, which was made out of thin boards, in relation to the window openings. The representation of the surface at this scale demanded a physical model of high ac-curacy. A surface diagram was created in the digital model, which showed how the surface would be analyzed to the boards. Their size is decisive for the development of the in situ installation. The boards were represented by slices of colored graven brazen that were applied on the surface. Due to the model’s great degree of detail the group was in position to locate all the key points for the in situ assembly as well as to discuss some details with the workers that were about to construct the boards.

At the time of industrial fabrication, the side car-rier elements were made with CNC machines from agglutinated wood timber, an extraordinary material that combines the resistance of steel, the ductility

image 71: combination of section and floor plan and the the translationimage 72: photo of the skin in relation to its context

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image 73: exploded axonometric of the BIMimage 74:Building infromation model’s components : a) the metal-lic slab and the hanging lower part, b) the conrete slab, the side structure and the frontal balconies, c) addition of wall panels and of circular rings, d) assembled stucture with all its components το ( from top to down)

image 75: view of the building from the village

of concrete, the levity of wood and has exceptional capacities. Amann constructors specialize in the pro-duction of structural beams with multiple agglutinated leafages. Since the frame was digitally designed and fabricated so as to achieve materials’ mechanical resistance, it sounded ironic to cover it by thin boards that a local eighty year old artisan constructed with an ax. Then the thin boards were riveted by the rest of his family. The last model generation was now informed with data concerning the armos between the finishes. At this point the presentation of perspective detail sec-tions (using the technique of hidden lines appearance) was very helpful. These representations successfully achieve to communicate the information not only for the assembly, but also for the final look of some impor-tant points.

5.3.5.Model in 1:1 scale

The detailed final digital model was tested with the construction of a typical building part in 1:1 scale. It was constituted from a window, its pareies and the carrier side elements. The real size model was con-structed in site and was a critical point of the project as everybody was then convinced that the construc-tion of the building was possible. The construction’s development showed how a building of such peculiar form could adjust so well to the physical environment. Although the building’s veneer was created with thin boards, traditional of the Alps architecture, the high technological structural frame that holds them justifies the project’s name, Chesa Future, which means the house of the future.

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image 76: view of the building in its context with the Alps in the background

5.3.6.Development

Hugh Whitehead states “ Through the experience of City Hall we learned the importance of being able to post-rationalize building geometry. In the case of the Chesa Futura, we were able to embed the rationale in the tools used to create the form. The developement of customized utilities is now based on a function library, which extends with every project undertaken and is structured to allow functions to be combined by the user without having to prescribe the workflow.”

Finally, it is worth telling that most architects have been educated in programmed thinking. Despite this fact hav-ing neither the time nor the tendency to develop programming abilities they don’t acquire the media to express or explore such a way of thinking. Mentally, designers have long over passed CAD software that mainly contain sys-tems for structural, affinity and time descriptions. What is needed is some time for adaption and familiarity with the specific peculiarities of the new medium, a fact that always follows the introduction of a new condition.

6.[Summary]

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image 77: Photo from the of Μuscle Tower at TU Delft (TU Delft)

6.1.Conclusions

In digital design fabrication the harmonious relation-ship between design and fabrication, which could be achieved with the use of digital media, offers an im-portant opportunity of reconsidering these process-es in architectural field. Their intense application nowadays makes this ability easier to understand. the introduction of digital fabrication, given the fact of the wide use of digital design (CAD environments) even in a limited way, ensures at least a better com-munication between these two phases. This direct communication assures error prevention, which many times arises from the obliged translations between analogue and digital and vice versa. This was happening routinely the past few years due to the lag between design and fabrication technology. Products that were designed with the aid of updated programming environments were fabricated with old techniques that were stationary the past years. In many cases, this disagreement was hidden, judging from the result. This, of course, does not mean that it was absent from the process. The embodiment of CNC machines constitutes the first step for bridging the gap between digital design and construction as it restores part of this communi-cation circle. Better understanding of design

software and the development of programming abilities, aiming at the at will adjustment of these environments constitutes the piece that closes this circle. Code and macro commands’ writing, for the creation and manipulation of design operators in a digital environment, would not be an exaggeration to be parallelized to the development of abilities in the use of pencil and paper in the physical environment. Undoubtedly, we should deeply examine the mean-ing of introducing DDF (digital design fabrication) in architecture. Apart from harmonically unifying design and fabrication, DDF has some important financial benefits. As Bernhard Franken informs us, many times architecture produced with a DDF process costs less than a conventional building construction. For example, in Frankfurt’s 2001 International Exhi-bition, BMW’s “Dynaform” pavilion that was fabricat-ed based on DDF techniques cost one third less per square meter than the corresponding ortho-regularly and conventionally constructed pavilion of “MINI” that was sponsored by the same company. Further-more, DDF’s introduction in architecture presents the important challenge of mixing together many practices that until recently were separate. In these observations one should add the experimental at-

tempts in the field of IA/interactive architecture/swarm architecture ( Verb, Natures, 2006). This field examines how the use of DDF and other sciences could help us expand our understanding of architecture and space. It studies adjustable to the outer conditions facade constructions. Additionally, it examines the fabrication of light sensitive roofs, which open and close depend-ing on the space’s solar radiation, and the structure of which change depending on the use. Such applications no longer exist as science fiction but are actually real-ized as pilot programs. A brilliant example is the Muscle Tower that was presented in Aandrijftechniek exhibi-tion during industrial design week, in the Netherlands in 2004. It is a structural construction model in 1:20 scale that interacts with the interior (users) and exterior (climate) conditions and behaves respectively. In any case, one should consider whether the introduction of this method actually provides a solution in complicated problems or simply produces complicated solutions for simple problems.

The easy regression both from one stage of design to another and from design to fabrication constitutes an important advantage. The classical deterministic model of a linear architectural production has been set aside. Architects are now asked to design and code a produc-tive rule system that is being controlled from a group of

parameters (relations, influences, constrains, rules) that are introduced as data. Architects choose from a group of results that they control. These results undergo fur-ther changes based on other parameters (material con-straints) and produce new ones. The process is devel-oping in a spiral form and stops whenever the architect decides it to. There are multiple benefits, as continuous process information is encouraged, while it is methodi-cally led to a clearly coded and parameterized target.Key point of this process is the group of parameters that are set for its control (the results’ unpredictability, due to the computations that are involved in the pro-cess, constitutes for many people the digital translation of the creation. Non linearity, “exact” vagueness and emersion are legitimate conditions.)

It is a well known fact that every tool originates from a culture and has to serve it. At the same time this tool produces a new culture that is not always distinct and often gets by unnoticeable. The introduction, though, of a new tool does not necessarily mean the abandonment of the previous ones but on the contrary demands their combination so as to attain the best result. This fact is obvious in the example of Chesa Futura, where current and traditional techniques are combined in a way that one could not distinguish one technique from the other. The application of digital design and fabrication tech-niques does not exclude previous working techniques, but on the contrary it seems to be fed by them. Critique on DDF, though, based on arguments extracted from traditional ways of working is rather absurd and leads to a dead-end.

6.1.Experiments

A first step towards the application of digital design and fabrication techniques was done with the further elabora-tion on the design operators’ concept developed by S. Dritsas (Dritsas S.2004) and with the developement of an own script (RVB script) for the realisation of double-curve surfaces out of interlocking flat elements. This concept will be further tested by the final design and production of a furniture series. A second experiment for future research will include a study on fully constrained motions. We will focus on one particular case, that of Bennet Linakge (image 78) and we will attempt design a environment responsive (kinetic) de-sign artefact.We will attempt to prove the above conclu-sions by implementing digitally from one side the design and the fabrication and the behavior on the other side of such an artefact based on a given set of operators (Grass-hoper. Rhino) and fabrication technologies (laser cutter).

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“The fascinating thing about technology is once you have a sense of what it can do it fills the imagination. I am sort of a hopeless case of being like a monkey with a stick poking into an anthill. But one realizes that the essence of technology is not the stick-the stick is ust a stick- it is in the desire for ants that propitiates. This is the real point at issue for a cultural descourse” dECOi /Goulthorpe,M.,(Kolarevic, B., 2003)

image 78: study on Bennett linkage (render)

[βιβλιογραφία]

[Bibliography]

Actar/ Verb: Architecture Boogazine/ issue Natures/ Barcelona, Sp/ Actar press, 2006/.Copeland, B.J/ «The modern history of Computing»/ The Stanford Encyclopedia of Philosophy (Spring 2001 Edition) / Edward N. Zalta (ed.)/ 20 April 2000/ URL= http://plato.stanford.edu/archives/spr2001/entries/computing-history/. Dritsas, S. / “Design operators” / Master of Science Thesis, Massachussetts Institute of Technology, MIT University/Cambridge/ MA: MIT,2004/. Eastman, C M / “Building product models: computer enviroments supporting design and construction”/ Boca Raton, FL/ CRC Press, 1999/.Kolarevic, B, ed./ “Architecture in the digital age-design and manufacturing”/ Abdignon / Taylor and Francis group,2003/.Meredith M./ “never enough,in the from control to design”/ ed. Sakamoto, T., Ferre A./Barcelona/ Actar press, 2007/.Mitchell W.J/ «the logic of Architecture: Design, Computation and Cognition»/ Massachussetts Institute of Technology MIT University/Cambridge, MA: MIT/ MIT Press,1990/.Mitchell, W.J., McCullough/ “Protoyping” (chapter 18) in Digital Design Media, 2nd edition/ New York/ Van Nostrand Reinhold,1995/.Pantazi Magdalini-Eleni/ “Dissecting Design: Exploring the Role of Rules in the Design Process”/ Master of Science Thesis, Massachussetts Institute of Technology, MIT University/Cambridge/ MA: MIT,2008/. Saas, L., Botha, M./ “the instant house: A Model of Design Production with Digital Fabrication”/ international journal of architectural computation/issue 04,volume 04/ 2001/ . Saas, L. / “Materalising Design: the implications of rapid prototyping in digital design”/ Massachussetts Institute of Technolog MIT University/Cambridge/ MA: MIT,2008/.Sakamoto T, Ferre Albert, ed./ “from control to design”/ Barcelona, SP/ Actar Press, 2007/. Tεγοπουλος , Φυτράκης/ “Μείζον Ελληνικό Λεξικό”/ Αθήνα, Ελλαδά/ εκδόσεις Τεγόπουλος-Φυτράκης. 2008/. Terzidis, K./ “Algorithmic architecture”/ Massachussetts Institute of Technology MIT University/Cam bridge, MA: MIT./ Architectural press,2001/.Tesselion: Adaptive Quadrilateral Flat Panelization/ Tibbits Skylar, Philadelpheia, 20 May 2008/ http://tesselion.wordpress.com/

[image index]

Kolarevic Branko, (2003), “Architecture in the digital age-design and manufacturing” ,pg. 94-100εικόνες (03,14,19,27,28,32)Verb: Architecture Boogazine, (2006), issue Natures,pg. 42-45, 54-64,(images: 01,07-09,13.14)author’s archive (images: 02,04-06,67)Saas lary (images: 29,30,33)-case study images.rapid prototyping and fabrication operator:Dritsas Stylianos (pg 35,38-42).Tesselion: Skylar Tibits(images37, 43-53) .Chesa Futura: Kolarevic Branko, (2003), “Architecture in the digital age-design and manufacturing” ,(images 55-66)wikipedia(images: 20-26,34)flickr.com(images: 36,54,65,66)-images from the internet http://tesselion.wordpress.com/, access on στις 15/06/2009 http://flickr.com/, access on 15/06/2009 http://wikipedia.org

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[Acknoledgements]

At first, I would like to express my gratitude to Stavros Vergopoulos, the supervisor professor of this dissertation project , whose help and useful guidance were of significant importance in thedevelopment of this research.I would like to also thank my friend Schina Kostas as well as my sister and architect Pantazi Magdalena for their interest and felicitous comments on my writings. Their help was determining in the development and proper expression of my realm of thought.I am grateful to my friend Gkogka Vic-Symbolink- for his comments on the graphic layout of this publication. Moreover a big thanks to Kosta Sfika for letting me use his laser cutter and thus allowing coming into contact with digital fabrica-tion and testing some ideas in real.I would like to thank all my colleagues at 101&107 ‘kamarakia’ (diploma-classrooms) at AUTH university, for being always willing to share thoughts and discuss the subject from different perspectives, but also for their tendency to act and react collectively.Last but not least, a big thanks for my parents and architects Pantazi Spyro and Margaritidou Eleni, for their help and support of my studies and ventures as well as my brother Pantazi Iason for his advice and rich insight.

/BDDF-09//Bridging Digitally Design&Fabrication/AUTH, Greece, June 2009/student: Pantazis Evangelos/Supervisor: Vergopoulos Stavros