rendering

theory topics

 

On this page are the steps for you to learn about and complete an Orthogonal Drawing to approved Australian Standards. (AS 1100)

  1. Rendering
      • What is rendering?
      • Get the story straight.
  2. Rendering for Form
  3. Creating surface
  4. Cast Shadows
  5. Media for rendering
    • What can we use to create surface texture and shade

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1 rendering?

 

What is rendering?

 

Rendering is a process where designers, artists and illustrators enhance the surface of their artwork. Three dimensional drawing is kind of an illusion. What I mean by this is that artists can achieve the effect of 3d on paper when it isn't really 3d. How do they do it?

 

3d rendering falls into codes and conventions of visual literacy. That is when we see 2d things represented in certain ways - we interpret them as 3d. We believe in the effect of depth so strongly, we refer to such drawings as 3 dimensional.

 

There are many ways to created the effect of three dimensions on paper. Some of these ways include; the use of scale, overlap, oblique lines and angles and even the use of different colours can create depth. However, even if a designer uses these visual devices, they will find they need to enhance their drawing and develop form by the application of tone. The use of different tones on different parts of the drawing creates the effect of light falling over an object naturally.

 

Get the story straight

 

When we tell a story about what happened last weekend, for example, we use literacy. We use words; verbs, adjectives, nouns, etc. The English language is literacy. When we tell that story we have to tell it using language methods (syntax and conventions) other people are familiar with. Writers use different conventions for making the story mysterious, funny, romantic or sad.

 

In the same way, when we use visual literacy to represent an object or a building, we need to use our visual conventions to form the image. And, just in the same way as when we tell a story with words, we need to use visual conventions in ways people understand. This normally means that we imply that there is a light source on an object, that the light source is above and that shades of various depth or colour and/ or tone darken our object progressively as they reach a point directly opposite the point where the light hits.

 

It will be important for you to learn how to put these conventions into practice to enable you to tell a story with the meaning you intend. In this way your audience will read your drawing correctly and see your object in 3d.

 

Not all people tell a story in the same way. Some people make jokes. The artist Pablo Picasso was famous for confusing viewers with his paintings. He used colours in a background seam to would leap forward yet soft pale colours in the foreground that should fade into the distance. But this was for a good reason. Picasso wanted us to see familiar things differently. He wanted to ingnite our imagination.

 

However, our job as illustrators in Visual Communication Design is to create a realistic representations of things. This chapter will show you how you can learn to fool people perfectly into believeing that your image is really 3d.

 

rendering communicates form and surface

 

An amazing water colour illustration on aircraft by Wilf Hardy, Eagle Annual, 1963.

Here's how it's done! Rendering of textuers and tones by Robert W Gill, "Rendering with pen and ink",p273,1973, 1984,Thames and Hudson,

 

 

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2 rendering for form

 

What is a form?

 

Form is the name given to a 3 dimensional shape. A form can be created by angled lines or shapes. However, when we draw forms with line alone, they lack reality. Forms in real life are seen with different shades of their base colour as the light falls across their surface.

 

interpreting a light source 1

 

Before we begin shading to enhance the form of a draw object we must be aware of the location and direction of the light source. It is customary to work with a light source positioned above an object. However, in addition, the light source may be in front of the object (our side of the object) or behind. This position will greatly effect the way it is shaded. Before you render, make sure you have a clear idea about where the light source is. Look carefully at the images below. Look carefully also at the way the light source symbol is shown.

 

Look carefully at these images for the location and effect of a light source.

 

A light source in front and to the left of the object.
A light source in front and to the right of the object.
A light source behind and to the left of the object.
A light source behind and to the right of the object.

 

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Shading with tone

 

The first stage of rendering is to bring a form to life with shading. But what shades will I use? Consider the image below. I have created 10 steps from white to black. Let's say we give these numbers. Call white 0 and black 10. All the steps in between are 1 - 9. This is your tonal range. You have 10 different tones to use on any black and white illustration.

 

tonal graduations

 

An illustrator's keyboard. 10 evenly spaced tones from white to black.

 

three geometric forms enhanced by tone

 

A cube's form is enhanced with three flat planes of different tones. Use a light, a medium, and a dark tone.

A cylinder's form is enhanced by the same three tones in an evenly graduated (blended) spread. This is called a 'linear' gradient. In a linear gradient the tones blend along parallel axis (lines).

A sphere's form is described by the same three tones in an evenly blended gradient in both axis. This is called a 'radial' gradient. In a radial gradient the tones blend in both directions - vertical and horizontal.

 

Look back at the three images of geometric forms above. How have the tones been appied? If the cube has a light, a dark and a medium tone, what number tones would you say have been used on each plane?

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Rendering for colour with tonal graduations

 

When we render to enhance form alone we do this without respect to what colour an object might be before we apply light, medium and dark tones to its surface.

 

What colour is the box?

 

Each of these rectangular prisms is rendered with a light, medium and dark tone, but they are all rendered with a slightly different range. This is done to represent different colours for each form.

Here is another fabulous water colour illustration of transport vehicles by Wilf Hardy, Eagle Annual, 1963. Can you see how he has rendered the white car and the black rocket with a different range of tones?

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What colour is a colour?

 

tone and colour

 

This example is a fine rendering done to represent two different colours on a cube in black and white. CLC 2008

This example shows the same cube but in colour. Note how the student has created different 'colours' (actually tones of each colour) to represent the light, medium and dark of each. CLC 2008

 

In these two fine examples, A Year 11 student has shown the checker board box in two ways. She has developed light, medium and dark tones to represent two different, contrasting colours.

colour in colour

 

Look at this wonderful rendering of a World War II bomber the 'Mosquito' by Rykyu Watanabe, 1981. Can you see evidence of different groups of tones used to represent different colours? Compare the black and white stripes with the grey in the main body of the plane.

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3 creating surface

 

How real can i make it?

 

Rendering suface texture and sheen gives ultimate realism to your work. This image of a Willie Wagtail is by illustrator Peter Trusler. (Birds of Australian Gardens, Koot, McCulloch, Trusler, Rigby, 1980, p101).

 

What will I have to render?

 

In Visual Communication Design you will have to be able to render many surfaces. First learn how to be able to create them in 2d in 'swatches' then move onto 3d examples using the techniques in shading you learnt above.

 

You wlll have to learn how to render:

Let's take them one by one.

 

Soft

Cloth, leather/vinyl, plastic, paper.

 

Hard

Wood, metal (chrome, satin), coloured plastic (chrome, satin), brick, concrete.

 

Transparent

Glass and plastic (clear or transparent).

 

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A three step process

 

In most cases rendering any textured surface involves a three step process. This applies to most materials. This is;

  1. Create a base tonal rendeirng - without trying to represent the texture of the object. Keep it light, the texture will add tone to your work and darken it,
  2. Create the texture. Use lines in directions that make the texture look real,
  3. Add further shades or details or highlights with white pencil or paint on a fine brush.
  4. (A fourth stage can be to add cast shadows on the ground. We will come to this later).

I have examples for several of these. Look below for detailed techniques.

 

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rendering materials and surfaces

 

Soft materials

 

fabrics

 

Here is a close up of the textured fabric chair.
First, put down your light, medium and dark tones to block in your form.
Next, go over the form with lines to represent the texture. Finish off with some white painted details.
Here is a rendering I did with coloured pencils of corduroy boots. Note that with this kind of finish their are no deep shades or bright highlights.
Here is a marker rendering I did of a pair of shiny black leather boots. I worked it up with greys, leaving gaps for the paper to show through. Finally I finished with some white paint. Note on shiny surfaces you get real deep shadows and very bright highlights.

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Hard materials

 

wood, metals, plastic

 

Make up a stack of boxes in isometric or 2 point perspective. Render them to show shiny and matte surfaces.
To make killer wood: Draw your box in isomtric. First, put down your base tones; light, medium and dark. As an extension, I made different 'planks' slighlty different shades of my base colour.
Next, go over the form with lines to represent the texture. Finish off with some really sharp dark lines to emphasise the boards.
Here is a nice visualisation drawing (CLC 2008) of a cabinet.
Try something really shiny for a challenge.
I did it in Copic markers. Note: it is the reflections that we really draw.
I included this photo of a 'Knife man' knife holder to show you how satin steel and gloss plastic shine differently.
Here is the famous 'Hot Bertha' kettle by Phillipe Stark. It is made from satin plastic and aluminium. Try to render these textures.
Here is a pencil rendering over a freehand 2 point perspective drawing of Lego blocks. Note: I tried to shown reflections on the shiny surface. I finished off with some thin white paint lines. Can you pick them out?
Here is a quick computer rendering showing the difference between satin and shiny metal. The best thing you can do is look at real surfaces and try to render them.

surface sampler

 

Try making one of these sampler pages before you go into an exam. This is your best training.

 

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Transparent materials

 

glass and plastic

 

Here is a simple computer rendering showing glass.(CLC 2008)
Here is a nice computer rendering by Mariana Velo Year 11. Note the shines and transparency treatments.

 

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4 cast shadows

 

interpreting a light source 2

 

Before we begin rendering shadows cast from object we must be aware of the location and direction of the light source. It is customary to work with a light source positioned above an object. However, in addition, the light source may be in front of the object (our side of the object) or behind. This position will greatly effect the way it is shaded. Before you render, make sure you have a clear idea about where the light source is. Look carefully at the images below. Look carefully also, at the way the light source symbol is shown.

 

Look carefully at these images for the location and effect of a light source.

 

A light source in front and to the left of the object.
A light source in front and to the right of the object.
A light source behind and to the left of the object.
A light source behind and to the right of the object.

 

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How to make cast shadows

 

There are two terms used when describing shading on renering. We need to be clear about them. Here's an explanation;

  1. Create shade to emphasise the form of an object = make gradients in tone on (and only on) the surface of the object. Just describe the light as it falls over the object's surface.
  2. Render or create cast shadows = create a transluscent shade (light grey you can sort of see through) that results from the light passing over, either protrusions on the object or the object itself, and are drawn either on the object or the ground.

The purpose of this section is to discuss number 2 - cast shadows; shade that is cast by objects.

 

It is a pretty difficult science to work out the precise position of cast shadows in a perspective drawing. If you really, really want to work them out you will need to refer to books on the subject. Alternatively, Google the it. Just as there are books on how to construct accurate, measured perspective projections, the same can be done with cast shadows.

 

The basic concept

 

What we need to know as students, is the basic concept of cast shadows. We need to know approximately how and where to draw them and more importantly how to align the sides of the shaded area. I have constructed a very basic illustration of this process. Read the steps below, then try it for yourself. Find out more information to try it on more complex examples.

creating cast shadows

 

A cast shadow formed by a light source and additional Vanishing Points. Look below for details on how.

Follow these steps to create cast shadows on any drawing.

 

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5 Media for rendeirng

 

What can we use to create surface texture and shade?

 

When we talk about media for rendering we are talking about what we use to make the marks that represent texture and/ or shade. There is a wide range of media available for this job. What we need to consider is, what will be the purpose of our rendering and what aesthetic effect are we trying to achieve? Do we want it to look soft warm and friendly - let's sketch in pencil, or harsh, clear and coorporate - let's do it in a computer program like Adobe Illustrator.

 

Take a look below for a selection of drawing methods and media that can be for rendering.

 

pencil, coloured pencil

 

A very simply done grey lead pencil rendering on an Isometric drawing. (CLC 2008).
Mix coloures to make a better tonal rendering with colour pencils. Leave white areas for refelctions.

 

ink pens, tech pens, biro, copic/ pantone markers

 

Tech pen used to describe surface and texture by Robert W Gill, "Rendering with pen and ink",p152,1973, 1984,Thames and Hudson,
Use pen to create texture when representing old things. Here is a picture of a Ford V8 'Blitz' I used to own.
Never, never say a Biro won't do! The humble ball point in everyone's pencil case is all you need to beautiful, sensitive tonal work.
Great, confident marker work. From "Sketching. Drawing techniques for product designers". Koos Eissen and Roselien Steur, Page One press.

 

watercolour, gouache, airbrush

 

The soft and transparent qualities of water colour have been used in this visualisation sketch for SAT 2014, Ashley Ripper.

A detail from a technical rendering in gouache (opaque water colour) by illustrator John Batchelor.
Detail from Mosquito illustration by Rikyu Watanabe. "Mosquito",Sweetman, Watanabe, Janes Publishing 1981.

 

computer vector, raster, CAD

 

When creating shapes use Adobe Illustrator. Illustration by Frances Reade, "How to be cool", Murdoch Press.
A tonal rendering utilises the features available in Adobe Photoshop, Ben Lambert, SAT 2014.

A simple visualisation sketch output for client evaluation made on Google Sketchup. Kieran Roberts, Mossa Studio, 2014.

 

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