Section
as Form Generator under Digital Environment
Prof. Shuenn-Ren Liou, BSc, MArch, DArch
Department of Architecture, Tunghai University, Taichung, Taiwan
e-mail: shuenn@thu.edu.tw
Abstract
Given the
development of digital design concepts and technologies, architects are
confronting a new territory of architectural form generation. Two
significant themes have emerged. One has to do “post-generation systems”
dealing with the analysis of existing precedents and the derivation of new
instances. The other has to do with “dynamic forces” dealing with form abstraction
based on process and
movement. This paper examines how section may be used as form generator under
digital environment. Two sets of design experiments are developed and conducted
to explore the aforementioned two themes. The concept and logic underlying the methodology of
the two design experiments are discussed. The processes and the products are
presented. The attributes characterizing dynamic forms are also identified on
the basis of the findings acquired from the experiments.
1. Approaches to Form Generation
Many scientific approaches to the problem of form generation in
architectural design have progressed greatly since the second half of the 20th
century. Along the progression, two significant
themes have emerged. One has to do “post-generation systems” which deals with
the analysis of existing precedents and the derivation of new instances.
Noteworthy among them is the shape grammar formalism initiated by George Stiny
and James Gips. [6] Many known
architectural precedents are employed as subjects for study such as Andrea
Palladio [7], Frank Lloyd Wright [3], and Giuseppe
Terragni [8]. The other has to do with “dynamic forces” which
deals with form abstraction based on process and movement. Noteworthy among them is
the animate form proposed
by Greg Lynn. [5] The purpose of this paper is to explore how section may be used as form generator under digital
environment. Two sets of design experiments are developed and conducted in response to the aforementioned two themes. Experiment I
places emphasis on the design from known to new and Experiment II on the
dynamic form making.
2. Experiment 1: Design from Known
to New
2.1 The process of analysis and generation
The first set of experiment addresses
the theme of design from
known to new. A method for analysing the morphological
structure of an existing building and generating the new form is developed on the
basis of “structural section.” The process of analysis and generation consists
of three
sequential steps:
the derivations
of the basic
form, the composite form,
and the plastic
form.
Step 1: The Basic Form
The derivation of the basic form is based on the analysis of a historic
sawmill building. An interesting structural difference is found in the
longitudinal cross section. The idea of “Difference” is extended to establish
the form generation mechanism. (Recall Derrida’s use of “Différance” for the discussion on time and space.) An operation called “Differential Generation” is
applied to generate the basic form as shown in Figure 1.
Figure
1. Basic Form Generation
The basic form is placed within the framework of
another existing building (a small sawmill attached to the historic one). Their
spatial and inter-relations are created through the application of an operation
called “Constructive Linkage.” The composite form is generated as shown in Figure
2.
Figure 2. Composite
Form Generation
Step 3: The Plastic Form
As shown in Figure 3, the composite form is made up
of 27 section frames. Each section frame is in turn made up of a number of
straight lines. Many contour shapes of the section frames need to be modified
for further processing. Following that, all of the straight lines are
transformed into curved lines through the application of B-spline. As shown in
Figure 4, the final form is generated through the application of the operation
called “Plastic Integration.” Note that each section in the final form consists
of four basic spaces and one to three overlaps in-between.
Figure
3. The Composite Form and
Its 27 Sections
Figure
4. The Final Plastic Form
and Its Sections
2.2 Formal Attributes
The final plastic form is characterized by the
overlaps in section. The formation and the shapes of the four basic types of
the overlaps are shown in Figure 5.
Figure
5. Basic Types of Spatial
Overlaps in Section
Moreover, the
combination of the basic types of overlaps provides the sections with a wide
variety of spatial morphology as shown in Figure 6.
Figure
6. Sections of the Final
Plastic Form
3. Dynamic Form Making
3.1 The process
of analysis and generation
The second set of design
experiment addresses the theme of dynamic form making. The idea of section is
employed as an archetype for abstracting the ostensibly complicated shapes
derived through human body movement. In the following experiment, basketball playing is
used as the subject for study. As shown in Figure 7, the experiment captures
the movement of dribble and represents it in a series of frames of frozen
states. Each frame shows that the gesture of the body occupies space in a
particular time. The contour shapes of the body gesture are abstracted and
superimposed in Figure 8. The overall dynamic form is generated from the
accumulation of the application of NURBS on the ever changing shapes of the
section through a period of time, as shown in Figure 9.
Figure
7. The Frames Captured in the Movement of Dribble
Connecting all pivot points such
as head, shoulder, elbow, wrist, knee, and ball using PLINE in CAD.
Figure
8. The Abstraction and Superimposition of the Shapes Derived from Body Movement
Figure
9. The Application of NURBS
on the Ever Changing Shapes of the Section
3.2 Sectional Spaces in the Dynamic Form
Five
basic dribble movements are recorded and analyzed respectively according to the
aforementioned process. Finally five dynamic forms are generated. The sectional
spaces in one of the dynamic forms are shown in Figure 10.
Figure
10. The Sectional Spaces at
Different Locations of a Dynamic Form
3.3 Formal Attributes
Each
of the dynamic forms appears as a longitudinal, curvilinear form with various
degrees of folds on surface. In contrast to the traditional geometric form, the
dynamic form is characterized by its apparent complexity and continuity. A
closer examination reveals that the visual effect of complexity and
continuity may result from the following formal attributes.
With respect to complexity, the
findings show that the sections of the dynamic form have no recognizable basic
shapes such as square, circle, and triangle. They instead
are irregular in shape. In addition, the composition of the sections normally
lacks of a clear orientation. The ambiguity in orientation is due to the
multiple axes underlying the
composition’s multiple directions. Moreover, the layers of composition are interweaving.
The alternation of the concave and convex surfaces also increases the effect of
unbalance. In summary, the complexity of the dynamic form is characterized by
the formal attributes like irregular shapes, multiple axes, interweaving
layers, and unbalanced composition. (See Figure 11.)
Figure
11. Complexity: Irregular
Shapes, Multiple Axes, Interweaving Layers, and Unbalance
With
respect to continuity,
foldness
and smoothness are the two key issues. There are various kinds of folds on the
exterior and interior surfaces. Nevertheless, all the folds are determined by size
and angle.
Smoothness can be realized as the continuous changes of folds within a limited
period of time and space. The changes of folds in different depths produce the
density of folds on the surfaces of the dynamic form.
Figure
12. Continuity: Foldness and
Smoothness
4. Discussion
and Conclusions
The two design experiments using section as form
generator under digital environment are presented above. The first experiment
deals with the design from known to new. The idea of “differential generation”
is employed for the analysis of the architectural precedent. The “structural
section” is applied throughout the three steps of form generation. It is found
that the structural section constitutes a good mechanism for understanding the
existing spatial structure and, on the basis of the understanding, for creating
a new form. The final plastic form is characterized by the four basic types of
the overlaps in section. The combination of the basic types also provides the
sections with a wide variety of spatial morphology.
The second experiment deals with the making of
dynamic form. The
idea of “section” is employed as an archetype for
abstracting the ostensibly complicated shapes derived through human body
movement. The contour shapes of the moving body are captured,
abstracted,
and represented in a series of frozen sections. The final
dynamic form
appears as a longitudinal, curvilinear form with various degrees of folds on
surface. It is characterized by its apparent complexity and continuity.
The problem of complexity can be addressed by the formal attributes like
irregular shapes, multiple axes, interweaving layers, and unbalanced
composition. The problem of continuity can be addressed by the issues of
foldness and smoothness. Smoothness can be realized as the continuous changes
of folds within a limited period of time and space.
It's difficult to use the formal principles such as
proportion, geometry, axis, symmetry, rhythm, and hierarchy, as applied in
classical or modern architecture, to address the problems of the
digital-generated free form such as the plastic form in experiment I and the
dynamic form in experiment II in this paper. From the above discussion, it is
clear that some more adequate terminology (e.g. Greg Lynn’s use of blob) is required.
A general framework for describing, understanding, and interpreting the
properties of these new forms also needs to be established in the discipline of
architecture.
In contrast to section, plan as the generator for
new architecture was ever advocated eloquently by Le Corbusier. In his Towards
a New Architecture, Le Corbusier stated: “The Plan is the generator.
Without
a plan, you have lack of order, and willfulness. The Plan holds in itself
the essence of sensation. The great problems of to-morrow,
dictated by collective necessities, put the question of ‘plan’ in a new form.
Modern
life demands, and is waiting for, a new kind of plan,
both
for the house and for the city.” Indeed by tradition
architectural research has paid much less attention to section than plan;
however, as reflected in this paper, it can be argued that “the essence of
sensation,” “the great problems of tomorrow” may exist in Section. It’s about
time to call for the development of a new discourse on section as form
generator in the new digital era.
5. Acknowledgement
This author would like to thank
Chi-Kuo Wang and Chi-Bin Chao, two members of the Team of Architectural
Morphology at the Department of Architecture, Tunghai University, for their
contributions to the above two experiments.
6. References
[1] Chao, C.-B., The Architectural From Operation Based on the
Framing Pattern of
Animation in the Digital Environment. Taichung: Tunghai Univ., 2007.
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and
Planning B 8, 1981, pp.
87-96.
[3] Knight,
T., "The Transformation of Frank Lloyd Wright's Prairie Houses into His
Usonian Houses." Transformations of Designs,
University of California, Los Angeles, Doctoral Dissertation, 1986, pp.
338-377.
[4] Liou, S.R., "Design from Known to New – Issues of Generative
Architecture under
Digital Environment." Proceedings of the 5th
International Conference on
Generative Art, pp. 31-38, 2002.
[5] Lynn, G., Animate Form, New York: Princeton,
1999.
[6] Stiny, G. and J. Gips, “Shape Grammars and the Generative
Specification of
Painting and Sculpture.” Information Processing 71, Freiman, C.
(ed. Amsterdam: North Holland, 1972, pp.1460-1465.
[7] Stiny, G. and W. Mitchell, "The
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[8] Vollers, K., Twist & Build:
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