3 The shape is developed further and begins to become more visible. SketchingFreehand sketching allows you to convey ideas very quickly. You should use sketching when drawing initial ideas or developing chosen designs.Sketching is carried out without the use of drawing equipment such as rulers or rubbers.The basic shape is drawn very lightly with a pencil to allow for repeated corrections.The shape is developed further and begins to become more visible.A bolder outline is drawn by applying greater pressure. This draws the eye to the image.
5 Grids and underlays Drawing in 3D can be difficult to begin with. There is a range of grid papers available to help you. The grid paper can be put under your working sheet to guide you.The different styles of grid are designed to help you draw different types of drawing:Squared gridIsometric grid
6 Perspective drawingsPerspective drawings give a sense of depth. There are two types:one point perspectivetwo point perspective.Both types have similar characteristics and involve the following:A horizon lineThis is at eye level. It is the line at which the ground meets the sky.A vanishing pointThis is positioned on the horizon line. The drawing is ‘pulled into’ the vanishing point.
10 Isometric drawingThere are two different styles of three dimensional drawing – oblique and isometric.This is how you draw an oblique projection:Then draw the same shape again, offset from the original shape.You begin with a 2D shape.Connect the images together.Rub out the lines that cross the image.Oblique drawings are not the best way to present your ideas. They only show one side of the shape in any real detail.At GCSE you must become competent in isometric drawing.
11 Isometric drawing This is how you draw an isometric projection: Begin by drawing the centre edge of your shape. Draw it vertically up the page.Then work away from the line, drawing lines up at 30 degrees.Connect the top two edges by working at 30 degrees again. They should meet exactly.This drawing shows the shape in more detail than the oblique projection.Put the two side lines in, making sure they are vertical.
12 Isometric drawingAny shape can be drawn as an isometric projection. For complicated shapes, remember to use crating (mentioned earlier in this presentation) to ensure that your shapes have the correct proportions.The ‘crate’ is drawn isometrically.
13 Working drawingsWorking drawings are informational drawings – they give full details of an object’s size in 3D, and how its various parts are arranged.All working drawings are done to scale so that they give an accurate representation.Different lines are used for different parts of the drawing:Continuous thick line – outside edgesContinuous thin line – inside lines and dimension linesChain line – centre linesDashed line – hidden detail
14 Orthographic drawings Most working drawings are third angle orthographic projections.They bear this symbol.They have to follow British Standards in a number of ways.Orthographic projections give three views in one drawing. The views they show you are:The views must be drawn perfectly in line with each other.plan viewfront viewside view.
15 Orthographic drawings Orthographic projections must be drawn to British Standard requirements, as shown above.
16 Orthographic drawings Orthographic projections can be done by hand or on the computer.Here is an example of a third angle orthographic projection done using ProDesktop.
17 3-tone rendering3-tone rendering is a shading technique using three varying tones of colour. The tone depends on the amount of light hitting each part of the object.The lightest tone is used where the light strikes the object most directly.The position of the light source dictates which surface carries each tone.A medium tone is used for areas that get some light.The darkest tone is used for areas that get very little light.
19 EnhancementYou can enhance the images you draw to give them a more impressive and realistic finish.The final outcome can vary greatly depending on the media used to render it. These are some possibilities.
20 Enhancement – thick and thin lines You can create a more realistic 3D image by applying thick and thin lines to it.A thin line is applied where both connecting surfaces that make up the line are visible.A thick line is applied where you can only see one of the two connecting surfaces that make up the line.
21 Enhancement – hatching Hatching is another way of rendering. It has three main uses:to highlight key areas or hidden areasto add a more three dimensional feelto represent wastage.Hatching is added with a pencil – a softer pencil is better if you want to vary the tone. You can also vary the density of the hatching.Hidden areaWastage (material to be removed)
22 Enhancement – textureTexture can be applied to objects to give the illusion of a surface finish. This can be used in presentation work to represent the materials the object will be manufactured from.Texture can be added with a variety of mediums and using different styles and techniques.Study the following textures and see if you can recreate them.WoodOne of the easiest textures to apply using different shades of brown, orange and yellow. The grain effect is very easy to draw once the object has been shaded.
23 Enhancement – texture Metal When applying a metal texture, remember your three tone shading. Build up the colour using grey and pale blue, then add reflective streaks as if the light is bouncing off the surface. You can do this using a white pencil or by rubbing out streaks of the base colour.PlasticPlastic is one of the more difficult textures to apply as it can be a very reflective surface. Use a technique similar to that of metal. Make sure the reflection lines follow the shape of the object.
24 Enhancement – texture Concrete The easiest way to apply this texture is with a series of dots. Place the dots closer together to create dark areas and further apart to produce lighter areas. Try to make the surface look uneven.FabricYou need to create a soft effect, so avoid using straight lines drawn with a ruler. Soften the edges and apply bold colours using strokes in different directions to give a woven texture. You can also use lots of short pencil streaks to produce a furry effect.