IGCSE Design and Technology - Graphics: Drawing Techniques
IGCSE Design and Technology - Graphics: Drawing Techniques
This document provides detailed notes on the drawing techniques required for the IGCSE Design and Technology 0445 exam. We will cover freehand, orthographic, isometric, and perspective drawing.
1. Freehand Drawing
Description
Freehand drawing involves creating a drawing without the use of measuring tools. It relies on observation, hand-eye coordination, and the ability to translate what you see onto paper.
Techniques
Outline and Shape: Start with a light outline to establish the basic shape and proportions of the object.
Contour Lines: Use continuous, flowing lines to define the edges and curves of the object.
Shading: Employ hatching, cross-hatching, or stippling to create the illusion of depth and form.
Proportion: Pay close attention to the relative sizes of different parts of the object.
Perspective (basic): Even in freehand, try to indicate a sense of depth by making lines converge slightly.
Tips
Practice regularly to improve hand-eye coordination.
Start with simple shapes and gradually move to more complex objects.
Use a light touch when sketching the initial outline.
Don't be afraid to make mistakes – they are part of the learning process.
2. Orthographic Drawing
Description
Orthographic projection is a method of representing a 3D object in 2D using parallel projection lines. It typically involves creating multiple views: front, top, and side views.
Views
View
What it shows
Front View
Viewed from the front of the object. Shows the width and height.
Top View
Viewed from directly above the object. Shows the length and width.
Side View
Viewed from the side of the object. Shows the height and length.
Key Features
Parallel projection lines: Lines in the object project directly onto the 2D view without converging.
Accurate dimensions: Orthographic views are used to accurately represent the dimensions of an object.
Hidden lines: Use dashed lines to indicate edges that are hidden from view.
Centre Line: A vertical dashed line indicating the centre of the object.
3. Isometric Drawing
Description
Isometric drawing is a type of axonometric projection where all three dimensions (length, width, and height) are equally foreshortened. This creates a 3D representation of the object where all lines are parallel to each other.
Key Features
All three axes (X, Y, and Z) are equally foreshortened at a 120-degree angle.
Parallel lines in the object remain parallel in the drawing.
No true perspective is used – all lines converge to a vanishing point that is not explicitly shown.
Typically uses thicker lines for the outline and thinner lines for internal details.
Drawing Process
Draw the three isometric axes (X, Y, and Z) at a 120-degree angle.
Establish the outline of the object using the isometric axes.
Add internal details, keeping in mind the isometric projection rules.
Suggested diagram: Isometric view of a simple cuboid.
4. Perspective Drawing
Description
Perspective drawing is a method of representing 3D objects on a 2D surface using vanishing points. This creates the illusion of depth and realism.
Types of Perspective
One-Point Perspective: All parallel lines converge to a single vanishing point on the horizon line.
Two-Point Perspective: Parallel lines converge to two vanishing points on the horizon line.
Three-Point Perspective: Parallel lines converge to three vanishing points (two on the horizon line and one above or below).
Key Features
Horizon Line: Represents eye level.
Vanishing Points: Points on the horizon line where parallel lines appear to converge.
Foreshortening: Objects appear shorter as they recede into the distance.
Overlapping: Objects that are closer appear to obscure objects that are further away.
Drawing Process (Two-Point Perspective)
Draw the horizon line and mark two vanishing points on it.
Draw vertical lines to represent the height of the object.
Connect the top and bottom ends of the vertical lines to the two vanishing points to create the receding lines.
Determine the depth of the object and draw horizontal lines to connect the receding lines.