3.2 Graphical modelling

Essential Idea

Graphical models are used to communicate design ideas.

Nature and Aims of Design

Nature of design:

Graphical models can take many forms, but their prime function is always the same—to simplify the data and present it in such a way that understanding of what is being presented aids further development or discussion. Designers utilize graphical modelling as a tool to explore creative solutions and refine ideas from the technically impossible to the technically possible, widening the constraints of what is feasible. (1.13, 3.7)

Aim

Aim 2: The development of ideas through graphical models allows designers to explore and deepen their understanding of a problem and context of use.

Guidance

Related Sections

(non-IB content)

Concepts and principles

Sketching versus formal drawing techniques

Graphical models are 2D representations and communications of an idea. They are ways for a designer to quickly explore a number of possibilities, and then communicate these to users, clients, or their design team.

Designers might use sketching at the beginning of a design inquiry to quickly explore ideas and communicate the direction of their thinking. 

As the design becomes more refined, they may switch to isometric and orthographic drawings to create a higher fidelity model that could be used to communicate information about size, scale, etc. 3D renderings in CAD might be used to communicate with the client or other members of the design team. 

In each case, different types of models are being used to achieve different outcomes.

2D and 3D graphical models

Designers work with both 2D and 3D graphical models. 2D models represent detail, proportion, measurements, and relationships.

These can be considered "flat views" of an object

Orthographic drawings show all the details and dimensions of an object, and are typically produced at a high level of fidelity (detail).

3D graphical models show how design might look. Their purpose is to communicate a sense of proportion, scale, and aesthetics. 3D graphical models can take several forms depending on their function.

Both 2D and 3D graphical models typically include annotations in the drawing. Annotations are used to

It is expected that your sketches include annotations

Additional resources for Orthographic Drawing

Tinker Hatfield, Designer for Nike

Read the interview here

Designers use a range of drawings to communicate a 3D view of an object.

Orthographic Drawings

Orthographic drawings show the "side" of an object.

Features

Application:

These orthographic views of an iron show how the design looks from different perspectives. Each view is aligned with the others and is drawn to the same scale.

Isometric Drawings

Isometric drawings  show the shape and form of an object. 

Features

Application








The isometric view of the Mondrian chair shows its overall form.

Part and assembly drawings

Exploded isometric drawings show how an object with more than one component might be assembled. Parts are depicted in the order of how they are assembled.

Assembly drawings show how an object may be assembled. They may be shown as an exploded isometric drawing. Their primary purpose is to communicate the sequence of assembling a project.

Assembly drawings  include the names and numbers of parts, as well as bill of materials (BOM).  


Exploded isometric drawing of a pen. Source

Assembly drawings can be quite complex and have many steps. IKEA furniture, for example, is designed to be assembled by the user. Each product includes detailed assembly drawings. 

Kura Reversible  Bed full assembly instructions.  Click here to see the full detailed assembly instructions. Note how the instructions are communicated graphically, with no words.



Orthographic and Isometric drawings are important components of Criterion C and E(HL) of the DT IA. 

Below is guidance for preparing and presenting your Planning Drawings for Criterion C (SL) and Criterion E (HL)

Planning Drawing examplar

Download pdf of this poster here

Perspective Drawings

Perspective drawings are drawings showing an object as if viewed from a single point. They attempt to represent space by using foreshortening, and vanishing points. 

These types of drawings are often used in early planning stages to communicate what a design might look like. Most people are familiar with perspective drawings. They are a more accurate representation of what the design

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Comparison of orthographic and perspective rendering of a building. Notice how the perspective drawings have a vanishing point, while the orthographic does not.

Comparison of different graphical models

Advantages

Disadvantages

Sketching

Orthographic

Isometric

Perspective

Assembly