Graphical Modelling

What is Graphical Modelling?

• Graphical modelling refers to 2-dimensional ideation, namely drawings.
• The prime function of graphical modelling is always to to simplify the data and present it in such a way that understanding of what is being presented aids further development or discussion.
• It is a visualization of an idea, often created on paper using digital software.

Freehand vs Technical Drawing

• When making drawing, its purpose and audience should be taken into account.

Purpose

1. What does it need to do?
2. What should be made visible?
3. What characteristics should be emphasized?

Audience

1. Who will be seeing this?
2. What is the purpose of showing them?
3. What do I want to accomplish with them?

Freehand Drawing

• Freehand drawing includes rough sketches and simple ideation, without much in depth thought as to the feasibility and specifics of a design.
• It is used to put ideas down on paper and communicate and share them with others.

• Technical drawing is used when a design's idea more established.
• Proper measurements are used and feasibility and technical aspects are taken into account.
• These drawings are much more finalized than freehand drawings and are used to present ideas to clients or manufacturers.

• Generally using paper, pencil, crayon, marker, paint, sketch apps or a drawing tablet.

Main Purposes

1. Conveying concepts in conceptual modelling stage.
2. Scale (to show perspective and relation).
3. Aesthetics (appearance, visual appeal).

Advantages

• Quick and relatively easy.
• No specialized skills and equipment required.
• Helps to communicate with manufacturer and client.
• Annotations support understanding.

Disadvantages

1. May not look like the intended outcome
2. Lacks details

Examples

• Sketching, mind maps, doodles, (quick) drawing flat images, annotations

Technical Drawing

• Technical drawings replicate 3-dimensional spaces or show designs from multiple angles in order to give a more comprehensive idea of the design.
• Drawings are far more refined and often provide detailed measurements.
• (Grid) paper, pencil, fine liner, ruler, compass and technical drawing apps (SketchUp, Fusion360, Vectary) are generally used for technical drawings.

Main Purposes

1. Conveying concepts in conceptual modelling stage
2. Scale (to show perspective and relation)
3. Aesthetics (appearance, visual appeal)
4. Prototype preparation (create technical drawings for production)

Types of Technical Drawing

• For applying depth, perspective, thus showing multiple views on portrayed subject, various drawing methods are used.

Orthographic projection

• Orthographic/orthogonal projection, where different views of the design are shown (top, bottom, left, right, etc.)
• Main purposes are conveying concepts in the conceptual modelling stage and prototype preparation (technical drawings for production).

Advantages

• Detailed and accurate.
• Contains all necessary information.
• Can be constructed with IT.
• Easy to communicate with manufacturer.

Disadvantages

• Need specialized skills such as using CAD.
• Specialized equipment needed.
• Time consuming to create.
• Not easily understood by a layman (e.g. client).

Perspective Drawing

• 1, 2 or 3 vanishing points can be used can be used to convey a 3D space (4 or more vanishing points are not useful as they portray a "fisheye lens" where vertical lines are bent towards the vanishing points.).
• Main purposes are conveying concepts and showing external features.
• Can be used to show scale.

Advantages

• Looks like the real thing, it conveys the general look and feel.
• Easy and attractive to communicate with client.

Disadvantages

• Little detail regarding exact dimensions.
• Time consuming to create.

Isometric Projection

• Isometric projection is similar to perspective drawing, but there are no vanishing points. While this can look unnatural, it is useful as proportions do not warp like they do in perspective drawing.
• Generally done using 30-60-30 Isometric grid paper, pencil, fine liner, ruler, compass or technical CAD-drawing apps (Fusion360, Blender, TinkerCad) in order to achieve straight and even lines.

Main Purposes

• Conveying concepts in conceptual modelling stage
• Produced at final concept stage and used as working drawings in the realization stage

Exploded View

• Exploded view, where all the different parts of the design are shown.
• The parts are separated so that they do not obscure one another, hence making the design look as if its "exploded" into its separate parts.

• Exploded view drawings are almost always isometric as well, as it is the best way to convey all parts while maintaining their proportions to one another.

• Isometric exploded view: Isometric drawing of an object that shows how its multiple components relate and fit to one another
• Isometric assembly drawing: The drawing is ‘exploded’ to show components of a product and/or the sequence of assembly (identified by numbers and referring to a parts list).

Assembly Drawing

• Assembly or parts drawing is similar to the exploded view, but focuses more on the steps of assembly of the design.
• This can be very useful for manufacturers, for example.

Use Examples of Freehand and Technical Drawing

Purpose: Conveying your first ideas after a design brief to your design team. In this situation graphical modelling is mostly freehand.

Audience: To fellow designers, show ideas, get funding, creative process, get agreement, develop further.

Purpose: Presenting a final concept before preparing for production. Graphical modelling should be mostly technical.

Audience: To client; communicate concept, persuade, to manufacturer; explain product, check feasibility.

Purpose: Preparing the design for mass-manufacturing. Graphical drawing is technical.

Audience: To manufacturer; to enable and enhance production, high detail development.

Additional Terms

Graphical Models

• A visualization of an idea, often created on paper or through software, in two or three dimensions.

Sketches

• Quick and rough drawings of ideas used to convey or refine the idea.\

Projection Drawings

• Systems of drawings that are accurately drawn, the two main types are isometric projection (formal drawing technique) and orthographic projection (working drawing technique).

Formal Drawing Techniques

• A type of drawing technique that has fixed rules, the most widely used being isometric projection and perspective drawing.

Working Drawings

• Drawings that are used to guide the production of a product, most commonly orthographic projection, section drawings, part drawings, assembly drawings and plan drawings.

Perspective Drawing

• A set of formal drawing techniques that depicts an object as getting smaller and closer together the further away they are.
• The techniques are one-point perspective, two-point perspective, and three-point perspective. Objects get smaller the closer they are to these points, often called "vanishing points".

Assembly Drawings

• A diagram that shows how components fit together to make a whole.
• Typically presented in an exploded view.

Part Drawings

• Orthographic drawings of the components of an assembly containing details just about that component.

Scale Drawings

• Drawings that are bigger or smaller than the real product, but exactly in proportion with product.