1. Digital Architectures

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1. Digital Architectures

• Computer Graphics for Architects in 2004
  (Arch5302)
• Marc Aurel Schnabel
• Wednesday, 13 October, 2004

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Introduction

• Having abandoned the discourse of style, the
  architecture of modern times is characterized by
  its capacity to take advantage of the specific
  achievements of that same modernity the
  innovations offered it by present-day science and
  technology.
• The relationship between new technology and new
  architecture even comprises a fundamental datum
  of what are referred to as avant-garde
  architectures, so fundamental as to constitute a
  dominant albeit diffuse motif in the figuration
  of new architectures.
• Ignasi de Sola Morales 1997, Differences
  Topographies of Contemporary Architecture, MIT
  Press, Cambridge.

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Quote

• Integrating computer-aided design with
  computer-aided fabrication and construction ...
  fundamentally redefines the relationship between
  designing and producing.
• It eliminates many geometric constraints imposed
  by traditional drawing and production processes
  making complex curved shapes much easier to
  handle, for example, and reducing dependence on
  standard, mass-produced components. ....
• It bridges the gap between designing and
  producing that opened up when designers began to
  make drawings.
• Mitchell, W. and M. McCullough. (1995).
  Prototyping (Ch. 18). In Digital Design Media,
  2nd ed., 417-440. New York, Van Nostrand Reinhold.

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Digital Architectures

• Digital architectures refer to the
  computationally based processes of form
  origination and
• transformations. Several digital architectures
  are identified based on the underlying
• computational concepts such as
• topological space (topological architectures)
• isomorphic surfaces (isomorphic architectures)
• motion kinematics dynamics (animate
  architectures)
• keyshape animation (metamorphic architectures)
• parametric design (parametric architectures)
• genetic algorithms (evolutionary architectures)

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i Topological architectures

• In architectural curvilinearity Greg Lynn
  offers examples of new approaches to design that
  move away from the deconstructivisms logic of
  conflict and contradiction to develop a more
  fluid logic of connectivity. This is manifested
  through folding that departs from Euclidean
  geometry of discrete volumes, and employs
  topological, rubber-sheet geometry of
  continuous curves and surfaces.
• In topological space, geometry is represented by
  parametric functions, which describe a range of
  possibilities. The continuous, highly curvilinear
  surfaces are mathematically described as NURBS
  Non-Uniform Rational B-Splines. What makes NURBS
  curves and surfaces particularly appealing is the
  ability to easily control their shape by
  manipulating the control points, weights, and
  knots. NURBS make the heterogeneous and coherent
  forms of the topological space computationally
  possible.

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Guggenheim Bilbao by Frank Gehry
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ii Isomorphic Architectures

• Blobs or metaballs, or isomorphic surfaces, are
  amorphous objects constructed as composite
  assemblages of mutually inflecting parametric
  objects with internal forces of mass and
  attraction. They exercise fields or regions of
  influence, which could be additive or
  subtractive. The geometry is constructed by
  computing a surface at which the composite field
  has the same intensity isomorphic surfaces.
• These open up another formal universe where forms
  may undergo variations giving rise to new
  possibilities. Objects interact with each other
  instead of just occupying space they become
  connected through a logic where the whole is
  always open to variation as new blobs (fields of
  influence) are added or new relations made,
  creating new possibilities. The surface boundary
  of the whole (the isomorphic surface) shifts or
  moves as fields of influence vary in their
  location and intensity. In that way, objects
  begin to operate in a dynamic rather than a
  static geography.

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Cardiff Opera by Greg LynnBMW-Pavilion by B.
Franken
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iii Animate Architectures

• Animation software is utilized as medium of
  form-generation. Animate design is defined by the
  co-presence of motion and force at the moment of
  formal conception.
• Force, as an initial condition, becomes the cause
  of both motion and particular inflections of a
  form. While motion implies movement and action,
  animation implies evolution of a form and its
  shaping forces.
• The repertoire of motion-based modeling
  techniques are keyframe animation, forward and
  inverse kinematics, dynamics (force fields) and
  particle emission.
• Kinematics are used in their true mechanical
  meaning to study the motion of an object or a
  hierarchical system of objects without
  consideration given to its mass or the forces
  acting on it. As motion is applied,
  transformation are propagated downward the
  hierarchy in forward kinematics, and upward
  through hierarchy in inverse kinematics.

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House in Long island by Greg Lynn

• Kinematics

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Port Authority Bus Terminal in NY by Greg Lynn

• Dynamic simulations take into consideration the
  effects of forces on the motion of an object or a
  system of objects, especially of forces that do
  not originate within the system itself. Physical
  properties of objects, such as mass (density),
  elasticity, static and kinetic friction (or
  roughness), are defined. Forces of gravity, wind,
  or vortex are applied, collision detection and
  obstacles (deflectors) are specified, and dynamic
  simulation computed.

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iv Metamorphic architectures

• Metamorphic generation of form includes several
  techniques such as keyshape animation,
  deformations of the modeling space around the
  model using a bounding box (lattice deformation),
  a spline curve, or one of the coordinate system
  axis or planes, and path animation, which deforms
  an object as it moves along a selected path.
• In keyshape animation, changes in the geometry
  are recorded as keyframes (keyshapes) and the
  software then computes the in-between states. In
  deformations of the modeling space, object shapes
  conform to the changes in geometry of the
  modeling space.

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Offices of BFL Software ltd. by Peter Eisenman
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v Parametric Architectures

• In parametric design, it is the parameters of a
  particular design that are declared, not its
  shape. By assigning different values to the
  parameters, different objects or configurations
  can be created. Equations can be used to describe
  the relationships between objects, thus defining
  an associative geometry. That way,
  interdependencies between objects can be
  established, and objects behavior under
  transformations defined.
• Parametric design often entails a procedural,
  algorithmic description of geometry. In this
  algorithmic spectaculars, i.e., algorithmic
  explorations of tectonic production using
  mathematica software, architects can construct
  mathematical models and generative procedures
  that are constrained by numerous variables
  initially unrelated to any pragmatic concerns.
  Each variable or process is a slot into which
  an external influence can be mapped, either
  statically or dynamically.

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algorithmic spectaculars by M Novak
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vi Evolutionary architectures

• Evolutionary architecture proposes the
  evolutionary model of nature as the generating
  process for architectural form.
• Architectural concepts are expressed as
  generative rules so that their evolution and
  development can be accelerated and tested by the
  use of computer models. Concepts are described in
  a genetic language which produces a code script
  of instructions for form generation.
• Computer models are used to simulate the
  development of prototypical forms which are then
  evaluated on the basis of their performance in a
  simulated environment. Very large numbers of
  evolutionary steps can be generated in a short
  space of time and the emergent forms are often
  unexpected.
• The key concept behind evolutionary architecture
  is that of the genetic algorithm. The key
  characteristic is a a string-like structure
  equivalent to the chromosomes of nature, to
  which the rules of reproduction, gene crossover,
  and mutation is applied. Optimum solutions are
  obtained by small incremental changes over
  several generations.

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pseudo-organisms by J. Frazer
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vii Virtual Environments

• The use of computer modeling and simulation to
  enable a person to interact with an artificial
  three-dimensional visual or other sensory
  environment. VR applications immerse the user in
  a computer-generated environment that simulates
  reality through the use of interactive devices,
  which send and receive information and are worn
  as goggles, headsets, gloves tracking devices,
  CAVES and other media.
• Augmented Reality
• Head Set
• CAVE
• Workbench
• Illusion-hole

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Immersive VE
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2. Digital Architectural Tools
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Introduction

• It was only within the last few years that the
  advances in computer-aided design (CAD) and
  computer-aided manufacturing (CAM) technologies
  have started to have an impact on building design
  and construction practices. They opened up new
  opportunities by allowing production and
  construction of very complex forms that were
  until recently very difficult and expensive to
  design, produce, and assemble using traditional
  construction technologies. The consequences will
  be profound, as the historic relationship between
  architecture and its means of production is
  increasingly being challenged by new digitally
  driven processes of design, fabrication and
  construction.

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Quotes

• Architecture is recasting itself, becoming in
  part an experimental investigation of topological
  geometries, partly a computational orchestration
  of robotic material production and partly a
  generative, kinematic sculpting of space
• Zellner, Peter. (1999). Hybrid Space New Forms
  in Digital Architecture. New York Rizzoli.

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Digital Fabrication

• Digital architectural fabrication refer to the
  computationally based processes of form
  production and fabrication based on a digital
  architectural model. Several digital fabrication
  processes are identified based on the underlying
  computational concepts such as
• 2D Fabrication
• Subtractive Fabrication
• Additive Fabrication
• Formative Fabrication
• Assembly
• Rapid Prototyping

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Digital Fabrication

• Implications of new digital design and
  fabrication processes enable the use of (vii)
  Virtual Environments (VE), (viii) rapid
  prototyping (RP) and computer-aided manufacturing
  (CAM).
• Technologies, which offer the production of
  small-scale models and full-scale building
  components directly to and from 3D digital
  models. Mass-customization is a development of
  repetitive non-standardized building systems
  through digitally controlled variation and serial
  differentiation.
• Geometries are precisely described and their
  construction is perfectly attainable by a
  computer numerically controlled (CNC) fabrication
  processes.

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i 2D Fabrication

• CNC (computer numerically controlled) cutting, or
  2D fabrication, is the most commonly used
  fabrication technique. Various cutting
  technologies, such as plasma-arc, laser-beam, or
  water-jet, involve two axis motion of the sheet
  material relative to the cutting head and are
  implemented as a moving cutting head, a moving
  bed, or a combination of the two. In plasma-arc
  cutting an electric arc is passed through a
  compressed gas jet in the cutting nozzle, heating
  the gas into plasma with a very high temperature
  (25,000F), which converts back into gas as it
  passes the heat to the cutting zone.

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Plasma-arc CNC cutting of steel supports for
masonry walls in Frank Gehrys Zollhoff Towers in
Düsseldorf
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Aluminum space frame for ABB Architects BMW
Pavilion is cut directly from digital data using
CNC water-jet technology.

• In water-jets, as their name suggests, a jet of
  highly pressurized water is mixed with solid
  abrasive particles and is forced through a tiny
  nozzle in a highly focused stream, causing the
  rapid erosion of the material in its path and
  producing very clean and accurate cuts.

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• Laser-cutters use a high intensity focused beam
  of infrared light in combination with a jet of
  highly pressurized gas (carbon dioxide) to melt
  or burn the material that is being cut. There
  are, however, large differences between these
  technologies in the kinds of materials or maximum
  thicknesses that could be cut. Laser-cutters can
  cut only materials that can absorb light energy
  water-jets can cut almost any material.
  Laser-cutters can cost-effectively cut material
  up to 5/8, while water-jets can cut much thicker
  materials, for example, up to 15 thick titanium.
  Digital Fabrication Manufacturing Architecture
  in the Information Age 3 The production
  strategies used in 2D fabrication often include
  contouring, triangulation (or polygonal
  tessellation), use of ruled, developable
  surfaces, and unfolding. They all involve
  extraction of two-dimensional, planar components
  from geometrically complex surfaces or solids
  comprising the buildings form. Which of these
  strategies is used depends on what is being
  defined tectonically structure, envelope, a
  combination of the two, etc.

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Structural frames in Frank Gehrys Experience
Music Project in Seattle Bernard Frankens BMW
Pavilion

• In contouring, a sequence of planar sections,
  often parallel to each other and placed at
  regular intervals, are produced automatically by
  modeling software from a given form and can be
  used directly to articulate structural components
  of the building, as was the case in a number of
  recently completed projects.

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• Complex, curvilinear surface envelopes are often
  produced by either triangulation (or some other
  planar tessellation) or conversion of
  double-curved into ruled surfaces, generated by
  linear interpolation between two curves.
  Triangulated or ruled surfaces are then unfolded
  into planar strips, which are laid out in some
  optimal fashion as two-dimensional shapes on a
  sheet, which is then used to cut the
  corresponding pieces of the sheet material using
  one of the CNC cutting technologies. For example,
  Frank Gehrys office used CATIA software in the
  Experience Music Project in Seattle to
  rationalize the double-curved surfaces by
  converting them into rule-developable surfaces,
  which were then unfolded and fabricated out of
  flat sheets of metal.

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Triangulated complex surfaces in Frank Gehrys DG
Bank Building in Berlin use of ruled surfaces
in the Water Pavilion by NOX in the Netherlands.
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Gaussian analysis of the surface curvature

• The surface data could be also used to directly
  generate a wire frame abstraction of the
  buildings structural framework, which could be
  then processed by the structural analysis
  software to generate the precise definition of
  all structural members. In Gehrys Bilbao project
  the contractor used a software program from
  Germany called Bocad to automatically generate a
  comprehensive digital model of the structural
  steel, including the brace-framed and secondary
  steel structures for the museum. More
  importantly, that same program was used to
  automatically produce the fabrication drawings or
  CNC data to precisely cut and pre-assemble the
  various components.

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ii Subtractive Fabrication

• Subtractive fabrication involves removal of
  specified volume of material from solids
• using multi-axis milling. In CNC milling a
  dedicated computer system performs the basic
  controlling functions over the movement of a
  machine tool using a set of coded instructions
  static geography.
• The CNC milling has recently been applied in new
  ways in building industry to produce the
  formwork (molds) for the off-site and on-site
  casting of concrete elements with double-curved
  geometry, as in one of the Gehrys office
  buildings in Düsseldorf, and for the production
  of the laminated glass panels with complex
  curvilinear surfaces, as in Gehrys Conde Nast
  Cafeteria project and Bernard Frankens BMW
  Pavilion.

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Milling of molds for the production of
double-curved acrylic glass panels BMW-Pavilion
by B. Franken
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Milling of Styrofoam molds for the casting of
reinforced concrete panels for Gehrys Zollhof
Towers

• In Gehrys Zollhof towers, the undulated forms of
  the load bearing external wall panels, made of
  reinforced concrete, were produced using blocks
  of lightweight polystyrene (Styrofoam), which
  were shaped in CATIA and CNC milled to produce
  355 different curved molds that became the forms
  for the casting of the concrete.

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iii Additive Fabrication

• Additive fabrication involved incremental forming
  by adding material in a layer-by-layer
• fashion, in a process converse of milling. It is
  often referred to as layered manufacturing,
• solid freeform fabrication, rapid prototyping, or
  desktop manufacturing. All additive
• fabrication technologies share the same principle
  in that the digital (solid) model is sliced
• into two-dimensional layers. The information of
  each layer is then transferred to the
• processing head of the manufacturing machine and
  the physical product is incrementally
• generated in a layer-by-layer fashion.
• A number of competing technologies now exist on
  the market, utilizing a variety of materials and
  a range of curing processes based on light, heat,
  or chemicals

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• Stereo lithography (SLA) is based on liquid
  polymers which solidify when exposed to laser
  light. Selective Laser Sintering (SLS) laser beam
  melts the layer of metal powder to create solid
  objects.
• In 3D Printing (3DP) layers of ceramic powder are
  glued to form objects.
• Sheets of material (paper, plastic), either
  precut or on a roll, are glued (laminated)
  together and laser cut in the Laminated Object
  Manufacture (LOM) process.
• In Fused Deposition Modeling (FDM) each cross
  section is produced by melting a plastic filament
  that solidifies upon cooling.
• Multi-jet manufacture (MJM) uses a modified
  printing head to deposit melted thermoplastic/wax
  material in very thin layers, one layer at a
  time, to create three-dimensional solids.
• Sprayed concrete were introduced to manufacture
  large-scale building components directly from
  digital data.

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Trypiramid Polsheks Rose Center for Earth -
Sciences, NY HKU Students work
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iv Formative Fabrication

• In formative fabrication mechanical forces,
  restricting forms, heat, or steam are applied on
  a material so as to form it into the desired
  shape through reshaping or deformation, which can
  be axially or surface constrained. For example,
  the reshaped material may be deformed permanently
  by such processes as stressing metal past the
  elastic limit, heating metal then bending it
  while it is in a softened state, steam-bending
  boards, etc. Double curved,
• compound surfaces can be approximated by arrays
  of height-adjustable, numerically-controlled
  pins, which could be used for the production of
  molded glass and plastic sheets and for curved
  stamped metal. Plane curves can be fabricated by
  numerically-controlled bending of thin rods,
  tubes, or strips of elastic material, such as
  steel or wood, as was done for one of the
  exhibition pavilions designed by Bernard Franken
  for BMW.

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Forming Kolatan Macdonalds house in
Connecticut

• The idea of a structural skin not only implies a
  new material, but also geometries, such as curves
  and folds that would enable the continuous skin
  to act structurally, obviating an independent
  static system The skin alone does the heavy
  lifting.
• Giovannini, J. 2000. Building a Better Blob. In
  Architecture 89(9) 126-128.
• The building is made of polyurethane foam sprayed
  over an egg-crate plywood armature that was
  CNC-cut, thus forming a monocoque structure that
  is structurally self-sufficient without the
  egg-crate, which will remain captured within the
  monocoque form

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v Assembly

• After the components are digitally fabricated,
  their assembly on site can be augmented with
  digital technology. Digital three-dimensional
  models can be used to determine the location of
  each component, to move each component to its
  location, and finally, to fix each component in
  its proper place.
• New digitally-driven technologies, such as
  electronic surveying and laser positioning, are
  increasingly being used on construction sites
  around the world to precisely determine the
  location of building components. For example,
  Frank Gehrys Guggenheim Museum in Bilbao was
  built without any tape measures. During
  fabrication, each structural component was bar
  coded and marked with the nodes of intersection
  with adjacent layers of structure. On site bar
  codes were swiped to reveal the coordinates of
  each piece in the CATIA model. Laser surveying
  equipment linked to CATIA enabled each piece to
  be precisely placed in its position as defined by
  the computer model. Similar processes were used
  on Gehrys project in Seattle. This processes are
  common practice in the aerospace industry, but
  relatively new to building.

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algorithmic GPS technology was used on Gehrys
Experience Music Project in Seattle to verify the
location of components
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vi Rapid Prototyping

• Computer Numerically Controlled (CNC) fabrication
  processes are cutting, subtractive, additive, and
  formative fabrication.
• Rapid Prototyping (RP) involves incremental
  forming by adding material in a layer-by-layer
  fashion. The digital (solid) model is sliced into
  two-dimensional layers the information of each
  layer is then transferred to the processing head
  of the manufacturing machine and the physical
• product is incrementally generated in a
  layer-by-layer way.

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CNC

• Bernard Caches Objectiles
• Gehrys "Zollhof" in Duesseldorf
• Bernard Frankens "BMW Pavilion"

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Mass Customization Bernard Caches Objectiles

• The ability to mass-produce irregular building
  components with the same facility as standardized
  parts introduced the notion of mass-customization
  into building design and production (it is just
  as easy and cost-effective for a CNC milling
  machine to produce 1000 unique objects as to
  produce 1000 identical ones). Mass-customization,
  sometimes referred to as systematic
  customization, can be defined as mass production
  of individually customized goods and services,
  thus offering a tremendous increase in variety
  and customization without a corresponding
  increase in costs.

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End

• Wednesday, 13 October, 2004 marcaurel_at_hku.hk