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Lab 2: Biofuels Pie

biofuels Pie

source (it's no longer here): http://www1.eere.energy.gov/biomass/printable_versions/about.html

In this lab, you'll recreate the biofuels pie above - not a brilliant visualization, but it will introduce some useful Illustrator skills. Along the way, I'll present ideas about the effectiveness of this visual and give you some ideas to produce another version that you think is more effective.

Step 1: Create a model layer

The first step is to paste a copy of the image you'll be replicating onto a layer and lock it so it won't be accidentally selected and moved or deleted. (Sound familiar?)

a. Open Illustrator, and create a new file.

b. Copy the image at the top of this page (the original is no longer avaiable at the US Government site where I found it). Paste the image (Edit->paste) into Illustrator.

c. Name the layer "model" and lock it.

locked 'model' layer

d. Create a new layer called "pie" above the model layer (to do this, go to the "Layers" panel and click on the "new layer" button new layer button at the bottom).

e. Save the files as "biofuelsPie.ai"

Step 2: Use the chart tool

Illustrator has a group of tools to produce various types of charts/graphs (pie chart, bar chart, line graph etc.).

a. Watch this video to learn about how the chart tools work.

b. Select the Pie Chart tool (remember that to get to the list of tool options available you click and hold on the tool button until the options appear:

chart tool options

c. Use the tool to draw a square that just covers the pie circle of the model (don't worry if it's not perfect, you can fix this later):

draw your pie

You can see from the model that the data values for the wedges are:
6, 31, 27, 28, 8

d. Type these numbers in a row across the top of the data box, then close the data box to see your pie:

initial pie

The next tasks will be to change the size of the pie and the color of the pie wedges to match the model.

We'll start with color. You'll need to select 1 wedge at a time. You'll find, however, that you can't do that yet -if you click on one wedge, the entire pie is automatically selected because the pie elements are grouped.

e. Watch this video to learn more about grouping and ungrouping elements in Illustrator.

f. Select your pie chart and ungroup it (Object -> Ungroup). You still can't select individual wedges because the original graph objects consists of groups of groups. So select it once more and ungroup it again (Object -> Ungroup). Now you should be able to click on and select individual wedges.

g. Drag your selection tool across all of the wedges to select them, and move them to the side so that your model is visible. Now use the eyedropper tool to color the wedges one at a time (you can rewatch this video to remember how to use the eyedropper tool if you've forgotten). Your finished result will look something like this:

wedges colored

h. Now move the pie back into place and adjust the size of the pie to match the model by selecting the entire pie, clicking on the "free transform" tool free transform tool, and holding down the shift key while you drag one of the corner points (if you don't hold down the shift key, you'll distort the circle into an ellipse).

Color: Color is a powerful tool in visualization. It can be used:
Color will do all of these things even if you're not intending to do so. In other words, it's natural for people to respond to color and expect it to mean something. if you have used color casually without thinking about the results, you're likely to confuse your audience or at least be less successful at getting your point across.

For now, the question is, what is color doing in this image? Do you think the designer chose these colors carefully? At the end of this lab, you'll experiment with color in this design.

i. Now select each wedge and pull it out a bit to match the model. Here's what mine looks like (I've hidden the model layer):

Step 3: Add shadows

If you zoom in close to the model image, you can see that each wedge has a slight shadow. The next task will be to create that.

A word about shadows and gradients
Shadows are a popular visual effect. They can look cool, and can be useful (e.g. to help an information box stand out from the surrounding image), but they can be over-used. Beware of the temptation to use them needlessly.

Vector versus Raster

Generally, Illustrator creates vector images as opposed to raster images; which means the information is encoded as mathematical formulas rather than as pixels). This makes file sizes much smaller and allows you to resize infinitely without an image becoming pixilated.

Some of the "effects" in Illustrator, including the "Drop Shadow" effect are raster rather than vector (they are defined pixel-by-pixel). Every Illustrator document has a raster effects setting which determines the resolution of the pixels. The higher the resolution, the less pixilated the effects will be and the larger the file size will be.

a. Watch this video about Drop Shadows.

For now, we'll use the built-it shadow effect, but it's good to know about optional ways to create shadows.

b. Select the pie wedges and choose Effect->Stylize->Drop Shadow.

Move your wedges aside so you can compare them with the model. The default shadow looks darker and larger than in the model:


c. To modify the drop shadow, select the wedges, open the "Appearance" panel, and click on "Drop shadow”:

You'll get a dialog box:

d. Click on the "preview" box so you can see what the shadow looks like as you modify it.

e. It looks like the shadows in the model are cast to the right (i.e. in the "x" dimension), but not upward or downward (not in the "y" dimension), so reduce the "Y Offset" value until it matches.

f. Click on the color box in the Drop Shadow dialog box to change it to a lighter gray:

Step 4: Add text

a. Create a new layer named "text" and lock and hide the "pie" layer.

Uses for text in visuals

label: Each pie wedged has a name that identifies what it represents ("corn," "crop residues" etc.)

add precision: The size of the wedges are proportional to the percentage of biofuel comes from each source, so the labels (e.g. "31%") is somewhat redundant, but helps compensate for the fact that our ability to judge differences between wedge sizes is limited.

annotate: Text can also be used to add commentary. We don't see that in this example.

Principles

The primary principle to follow is to place text as close to the visual element it refers to as possible. This example does a good job of that. It's not uncommon to see pie graphs which use a separate key to label each wedge. The problem with this approach is that your eye has to do the work of switching back and forth between the key and the pie.

In other respects, text elements should be treated just like other visual elements, e.g. if they're very important, they should be visuall prominent (perhaps darker or larger than other text). If they're minor, they should be small and subtle to avoid detracting attention from more important elements.

Here is a description of the process I went through in creating the text (you can either follow along and do the same, or read the description, then do it on your own):

I selected the "type tool" type tool and typed my first label "27%" -then compared it visually - the size looked about right, but it wasn't as bold as the model so I switched to bold:

selecting 'bold' text

I moved it right over the model - it looked a little smaller so I nudged the
size up to 15 points and found that it covered the original pretty accurately. I didn't change the font style -apparently they used Illustrator’s default font - Myriad Pro.

Next, I typed the remaining percentage numbers and moved them into position over the model. I used the eye-dropper tool to make them white (remember to select the text, then click on the eye-dropper tool and click on something white, like the background).

Next I typed the label “Crop Residues”. Clearly not the right font - the C is too open - and even when I adjusted the size to make the height correct, the word was too long.

I went to Type->Font and selected “Arial narrow” from the list of fonts- it’s pretty close, but not exactly right. I scanned the list again and tried out a few more fonts, but none looked as good, so I stuck with Arial narrow.

The lines of text are spaced too far apart vertically so I went to “Window->Type->Character" text spacing and adjusted the space between lines until it looked right (about 12):

text spacing

The letters are centered in the model so I clicked on the paragraph formatting option to align center:

align center

FInally, I typed the other headings and the source information. The source information title is the same font and size as the other headings, but the subtext is smaller so I selected just that text within the text object using the text tool (this can be tricky):

part of text object selected

I chose a smaller size -and made it not bold - it's not quite right, but close enough.

b. If you haven't followed along, go ahead now and do your best to copy the text from the model.

Step 5: Create the arrows

What are the arrows doing in this visual?

What do you think the arrows mean? (I don't honestly know myself). Are they there to point to the labels? Are they there to add a feeling of action and energy to the visual?

Edward Tufte, who is a VERY BIG name in information visualization, coined the phrase "Chart Junk" to refer to any elements of a visualization that are not informative. He strongly discourages all chart junk because of it's potential to confuse or detract attention from where it needs to be. Others might argue that visual elements can play a role that isn't strictly informational (e.g. setting the tone). Whatever your viewpoint, it's wise to always be on the lookout for Chart Junk consider removing it. But in this case, we'll keep it because it's an opportunity to learn some more useful Illustrator strategies.

a. Make your model layer visible and add a new layer just above it called "arrows." You can hide the other layers to keep them from getting in the way.

b. Use the line tool line tool to draw a line that starts at the base of the arrow and ends at the point. Before clicking elsewhere and de-selecting this new line, be sure it has a stroke color stroke, no fill (otherwise it will be invisible):

arrow line

b. Increase the stroke thickness until the line is as wide as the base of the arrow:

stroke thickness

stroke correct size

Remember the stroke thickness number because you'll need it in the next step.

c. With the line still selected, use the eye-dropper tool to match the color of the model. When you do this, you'll get a pale blue fill and no stroke which is the opposite of what you want, so click on the little reverse arrow to switch them:

stroke & fill colors stroke and fill switched

When you do that, the stroke thickness you entered will disappear so you'll need to fix that (you might wonder why I had you change the stroke size earlier when I knew you would lose it - I did it because it's a lot easier to match the size when your line is black then when it's the same color as the arrow you're matching).

Now you have a short, wide line that is the correct color. It's ready for an arrowhead. (The instructions that follow are for Illustrator version CS6, if you have an earlier version, you'll add arrowheads with Effect -> Stylize -> Add Arrowheads)

d. Open the "Stroke" panel:

arrowhead dialog box


A little over halfway down the panel, you'll see where you can create arrowheads. You'll notice that you can choose arrowheads for both the beginning and end of the line. The one you choose will depend upon which end of your line you drew first.

e. Browse through the style options to find an arrowhead that looks like the one in the model. The arrowhead will probably be WAY TOO BIG at first, so reduce the percentage until it's the correct size).

f. When you're happy with this arrow, create the other arrows. (NOTE: I found that I had to use a different arrowhead style to get the right look for the smaller arrows and I couldn't find an exact match so I just used the closest one -KEEP IN MIND as you're working on all of these exercises, that the point is not to produce a precise copy, but to learn how to use Illustrator. So explore and play with it, don't put a lot of energy into making it perfect. Instead, put your energy into learning how it works).

Your finished product will look something like this (if you hide the other layers):

arrows only

g. Now line up your arrow, pie and text layers so they all look right (to move the contents of one layer, be sure to lock the others so you don't accidentally move the wrong thing):

almost completed pie

This looks very similar to the model. The one missing element is the fuzzy look at the base of the arrows.

Step 6: Blur the base of the arrows

I'm not sure how the creator of the original graphic created the blurred look at the base of the arrows. My first thought was to use a gradient (something you'll learn how to do later). But gradients are a fill property and the arrows are made with lines (strokes). I could change the line to a fill (another thing you'll learn how to do later), but instead I thought some more and realized if I looked at the image as a whole it seems as if there is a blurred circle under the entire pie that covers up the base of the arrows. So...

a. Unhide (but don't unlock) the pie layer. Create a new layer just above the "arrows" layer called "blurred circle."

b. Use the ellipse shape tool to create a white circle that covers the base of the arrows (remember to hold down the shift key to create a perfect circle):

whiteCircle

c. With the circle selected, choose Effect->Blur->Gaussian blur (this is another raster effect).

blur dialog box

d. Click the Preview button so you can see how it looks as you modify the radius.OK to test the result (there is no preview for this effect). If you've closed the dialog box, but then decide you want to change it, open the "Appearance" panel and, with the circle selected, click on "Gaussian blur."

The result will look something like this:

pie with blurred circle

 

e. Make all of your layers visible (except for the model) and experiment with dragging the layers in the layers panel to rearrange them to see why what the effect of moving them is.

The final result should look something like this:

final pie

You're done (with the first part)! Save your file.

FINAL PRODUCT: biofuelsPie.ai

Summary

Chart tool: (chart tool video)

draw your pie

Grouping (video)

Effects

Text

style:

selecting 'bold' text

horizontal spacing: text spacing

alignment: align center

 

VISUALIZATION/DESIGN PRINCIPLES:

Color:

encode
evoke
highlight
set tone

Uses for text in visuals

label
add precision
annotate

Text placement

place text as close to the visual element it refers to as possible

Edward Tufte says avoid Chart Junk