CAD and Architectural Shaping

Key Concepts: CAD and Shaping Architecture

• Architecture emanates from an architect who is creative and skilled in drawing, where they conceive the building.
• The architect's role now includes modeling in addition to drawing.
• CAD systems can integrate digital fabrication technologies.

Evolution of Design Tools

• Sketchpad brought algorithmic logic and geometric relationships, enabling simulations and calculations.
• CAD initially imitated real drafting but eventually surpassed its limitations.
• Experimentation led to new approaches in CAD.
• AutoCAD and parametric design became prominent between 1982 and 2010, following early CAD developments in the 1960s.

Developments in Advanced CAD

• Research in complex geometry adopted techniques from industrial design, aerospace design, and animation.
• Before CAD, some geometric ideas were difficult to model physically and translate into drawings.
• Sydney Opera House's forms were geometrically approximated by cutting sections of a sphere, enabling its construction.
• Burry studied Gaudi's geometry, whose forms were geometrically derived (e.g., hyperbolic paraboloids).
• Frank Gehry used aerospace software to draw complex geometry for projects like the Bilbao Guggenheim.
• Animation software was used by architects like Greg Lynn and Bernard Franken for "blob" forms.
• "CAD is not a better way to draw, but a deeper way to think.”

Parametric Design & Generative Components

• Robert Aish developed Generative Components software, inspired by logic from the 1960s (e.g., Sketchpad).
• Parametric design brings new ways of thinking.
• Manual changes are difficult in traditional CAD.
• Parametric design overcomes traditional CAD limitations by adding new concepts.
• Parametric design requires looking at the logic of the design.
• Modern architects are “instruction makers” where parametric design becomes a step.
• Algorithmic design uses assumptions, precise procedures, fixed vocabulary, and clear instructions.
• Algorithmic design requires steps, but no intelligence for execution (procedural art).

Rationalization

• Rationalization is a structured methodology to translate conceptual designs into production and addressing technical challenges.
• The historical context has been innate to architecture, where classical sketches and drawings formalized design and construction. Design-computation is the modern medium.
• There are three types:
  • Pre-Rationalized: Design logic is predetermined, forms seem inevitable (e.g., 30 St Mary's Axe).
  • Embedded Rationalization: Logic emerges through experimentation during design.
  • Post-Rationalized: Geometry is rationalized after the conceptual phase (e.g., Sage Gateshead).

Geometry in Design

• Architecture is governed by geometry aiming to reduce designs to formal elements (lines, arcs).
• An exmaple is 30 St Mary's Axe, where its geometry was derived from a pine cone and pre-rationalized with tight design logic.
• Parametric control systems enabled its fabrication and construction.
• Design Rationalization bridges conceptual ideas and material reality. -Pre-Rationalized includes layered rules (lines, arcs, developable surfaces) using associative modeling (e.g., Waterloo Station, Eden Project).
• Post-Rationalized translates free-form concepts into buildable geometry later (e.g., Sage Gateshead's torus patches).

Overview - Geometry, Lines, Curves, Surfaces, Panelization and Modeling

• Focus on Geometry including Cartesian coordinates, points, vectors, lines, curves, surfaces, panelization and modeling strategies.
• Computational tools shape architectural form and fabrication.
• Mies van der Rohe (Seagram Building, 1958) is contrasted with Norman Foster (30 St Mary Axe, 2003).
• Digital architecture privileges experimental forms beyond modern limits.

Historical Context

• Shipbuilding was used by Romans with full-scale wooden templates for hull ribs, curves morphed along the keel (Nautical Arch, Yenikapi Project).
• Lofting: Drafting technique for plotting curves (ships, aircraft) in large spaces above factory floors.
• Splines: Flexible strips (wood/metal) bent with weights (“ducks”) for smooth curves in ship design.

René Descartes - Cartesian Coordinates

• Linking algebra to Euclidean space revolutionized geometry (17th century).
• 2D: Points defined by (x, y) relative to perpendicular axes.
• 3D: Triplet (x, y, z) with origin and consistent units enabling analytical representation of curves (e.g., equations like y = sin(x)).

Points and Vectors in CAD

• Point: A location in space, no size (p = [x, y, z]). Requires a coordinate system (Woodbury, 2010).
• Vector: Magnitude and direction (v = [x, y, z]). No fixed position; derived by subtracting points (v = p - q).
  • Vector Operations: Add vectors to points (p = q + v), scale vectors (u = 2 * p), cross product (a × b = perpendicular vector).
• According to Rob Woodbury (2010), CAD models are mathematical propositions—designers "prove” their work through geometry.

Curves and Splines

• Physical Splines: Elastic rulers bent through knots for smooth shapes.
• Computational Splines: curves defined mathematically by Paul de Casteljau (1963).
• NURBS (Non-Uniform Rational B-Splines): Defined by degree (e.g., 1 = lines, 3 = free-form), control points, knots, and weights.
• Weights adjust influence (non-rational = equal weights; rational = varied, e.g., circles).
• Used by Zaha Hadid Architects (2012) for fluid forms.
• Curve Parameterization: Curves defined by functions (e.g., x = t, y = sin(t)); t = parameter where parameters ≠ length, and equal t-steps ≠ constant speed.

Surfaces - Types

• Extrusion Surface: Curve extended linearly (e.g., a wall).
• Rotational Surface: Curve rotated around an axis (e.g., vase, torus).
• Ruled Surface: Straight lines connect two curves (e.g., hyperbolic paraboloids).
• Translational Surface: Curve slid along another curve (e.g., Hippo House, Berlin Zoo).
• Kunsthaus Graz (Peter Cook & Colin Fournier, 2003) - complex surfaces as buildable instructions.

Panelization Strategies

• Architects create instructions as drawings where complex forms require discretization into buildable parts..
• Rationalization is a structured process to translate concepts into production.
• Natural Flat Panel Solutions include:
  • Flat/planar panels ideally quadrilateral, and maximize repetition that align with adjacent panels.

Strategies

• Discretization: Continuous geometry becomes discrete components (e.g., breaking a curve into segments).
• Blobs (Double-Curved Surfaces): CNC-milled (e.g., Greg Lynn's Alessi Tea Pots, 2003).
• Triangulation: Planar panels from curved surfaces that works for any shape, but with no repetition and fabrication waste.
  • British Museum Great Court (Foster + Partners) and Biosphere (Buckminster Fuller, 1967) are examples
• Cones: Triangular panels from apex to base (e.g., GLA Building, Foster + Partners).
• Rotational Surfaces: Torus-based (e.g., 30 St Mary Axe diamond panels; Sage Gateshead's 21 torus patches) featuring tangency across boundaries (e.g., Gateshead Music Halls).
• Translational Surfaces: Quadrilateral facets (e.g., Hippo House, Berlin Zoo).
• Other Solutions: Smithsonian Courtyard (complex hybrid geometry).

Modelling Strategies

• Approaches:
  • Control Geometry can use points/vectors to define forms (e.g., NURBS control points).
  • Discretization breaks forms into parts (e.g., triangulation).
  • Placeholders are temporary elements to test designs.
• Grasshopper: -Has a data flow which inputs components, and outputs.
  • Data Types persist, and are volatile with recomputed solutiosn
  • Lists are core to Grasshopper and indexed from 0 (e.g., Series component for incremental values).
  • Reparameterization normalizes curve domains to 0-1.
  • Surface Normal is the perpendicular vector to a surface (via cross product).

Key Takeaways

• Geometry is the foundation of CAD and fabrication and bridges design intent and construction.
• The architect’s Task translates complex forms into instructions via panelization and modeling.
• Precedents: Roman shipbuilding/lofting, Foster's parametric towers, Hadid's NURBS-driven fluidity.

Strategies for modelling and fabrication

• Learn Grasshopper to create a Translational Surface, Custom Components, and Diagrids.
• Three ideas for Modeling and Fabrication, include Generation, Integration and Strategies. - Invention occurs in the gap between drawings and building where Digital fabrication a way of production using robots or lazercutter.
• Digit fabrication in architecture creates many ideas to define ways of digital fabrication as Contouring, folding forming and section.
• Shipbuilding has ribs which can be the basis for fabrication.
• The sections now are taking cuts to create 3d models such as in Ronchamp with 7 Parallel Sections, where Sectioning can be done in a waffle grid in 3 dimensions.

Forms in Buildings

• The form has a number of influenceing factors where We are not just technicians but architects and understand How can technology help us in this form process
• How can we translate form into computers by starting with a model using the computer to parametrically create a shape.
• Models and drawings were made to explore the form in real life, so the structure looked like windows, floorplanes, to keep it standing.
• Key elements of the building are dviiding form into floors, holding structure, core, and glazing/facade.
• A story around the model makes it a unique place and its Models are created for almost every part of the formmaking and process Example- flask, through the assistance with panalization.

Cutting

• Sectioning Surfaces can be created with seectioning used to create walls and structure.
  • This is applied in acoustic design using Parametrically modeling to create defusion, absorption, and deflection easily.
  • In cnc milling the computer numerically controlled milling is used for the subtractive process for g code.
  • When contrasting cutting and subtraction: addition builds up materials in layers rather than removing, and is used in rapid prototyping.
• FDM, 3D printing is the most common type of 3D printing, includes filaments, nozzles, and platforms.
• Theromorming heats, and shapes pliable plastic using a vacuum.
• Machines and softwares are used as tools that inform designs.
  • This relies on Sectioning and Tesselation where many pieces fit together with no gaps in 2d, 3d shapes and surfaces
  • origami is an example of folding using various materials to create panelling.

3D Printing

• General term for technologies that make objects with addition of material where the machines print model with multiple layers.
• Binder jetting has a printhead that drops liquid binder material into a powder to print layer by layer where it is fully joined edges faces and vertices.
• Powder bed fusion has lasers and electron beams fusing a region of powder selectively, which does not need structure supports.
• Vat photopolymerization uses a ultraviloet laser, and Material jetting is similar to printers that is liquid, jetted into a platform.
• Material extrusion is a common process drawn through a nozel, where Directed energy deposition has a Nozzole on a multi axis arm. and Sheet lamination include models.

Models and Fabrication in Design

• Models, Morphogenesis, Fabrication. are today’s topics
• A model represents real or imagined systems to understand specific aspects, where Abstracts reality into a reliable (often mathematical) depiction. It should also Represent something real or contrived and Aim for realiability.
• Sir Wren made St Paul's Great Model, Watson & Crick created the DNA Model, and Predictive simulations in Weather Models.
• Models FOR Design is a tool for architects to develop ideas and those models can be OF the Design is to scale, so models can be scaled for clients.
• Wind Tunnel Models where used to Model the Sydney Opera House, and There are also Competition Models

Morphogenesis

• Morphogenesis is the Process of form generation in natural and designed systems.
• Emergence which includes Structures arise from interactions of simpler elements. Text descriptions are translated into software processes.
• Inspirations from Nature are
• soap studies (Ted Happold, Frei Otto).
• Hanging Chain Models is used for structural form-finding, and MannheinGridshell is used for timber.

Natural Forms

• biological illustrations influencing Art Nouveau, like on mathematical basis of natural patterns
• Digital Morphogenesis: Focuses on geometry as the outcome without materialization.
• Natural Morphogenesis: Growth/evolution generate complex systems via material characteristics and environmental forces, with computational logic to integrate: Manufacturing constraints, Assembly logic, Material behavior and Structural, thermodynamic, acoustic simulations as generative drivers.

Fabrication Techniques

• Acoustic Surfaces (Cox & D'Antonio)
  • Absorption: Sound energy absorbed by material, Sound that bounces off, known as reflection.
  • Diffusion: Sound scattered for even distribution.
• Some test Geometries include: Shallow wave, deep wave, shallow hex, deep hex with cnc and Grasshopper.

CAD Tools

• Tool building involves:
  • Sketchpad which allows real-time interactive graphics.
  • Constraint for data
    • Model-View-Controller, which established CAD pen for drawing.

2. Formal Design involves Hierarchical decomposition of design through graphcs between human and computation.
3. Objects model real-world mental models through graphics and benefits.
4. Evolution of CAD Eras

• 2D limited creativity -BIM systematically delivers integrated graphics

5. graphs allow access to non-programmers and are combined to create light data.

Designing

• Digital tools integrate design and making with data
• Expands creative inquiry by closing the gap between simulation and realization.
• Limited to tooling and shapes
• Digital design embraces unpredictability within constraints, is iterative and designers shift from maker to editor.

Digital Tooling

• digital integrates processes, algorithms
• Subtractive adds planar surfaces to carve them for detail, but is time consuming
• Folding transforms sheets into strong components for fluidity
• Creates molds which has advantages but its time consuming
• profiles components by slicing which has quick Benefits
• 2D shapes create clear surfaces reducing wate