Unit Two -- Graphics

This unit focuses on working with images that, unlike photos, were not created with a camera, but instead created directly on the computer.  These types of graphics are useful in things like flyers, magazine covers, company logos, advertisements, or your family christmas card.  

However, there is a very important part of graphics that this course will only touch on a little...the artistic elements.  To make good graphics, you must understand what images are most pleasing to the eye.  Although this section will provide a few pointers along the way, to really understand this takes several courses of study, years of practice and a lot of hard work.  Instead, this course will focus on some of the basics of how graphics work, and how to use a few tools to come up with some very basic designs. 

If you want more information about the more artistic side of graphic design, you can start by reading through these articles:
http://en.wikipedia.org/wiki/Design_principles_and_elements
http://en.wikipedia.org/wiki/Composition_(visual_arts)
http://en.wikipedia.org/wiki/Color_theory
http://en.wikipedia.org/wiki/Aesthetics

Vector Graphics

Unlike raster images (photos, covered in Unit One) vector graphics do not consist of pixels arranged on a grid with different values. Instead vector graphics are stored as sets of instructions that a computer can run to re-create a graphic.

A simplistic example of these instructions could be:

  1. Create a circle with a center 3 units above the center of the image, and a radius of 2 units.

  2. Fill circle with yellow

  3. Create a line from 2 units below the center of the image to 3 units above and two units left of the center of the image.

  4. Create a line from 2 units below the center of the image to 3 units above and two units right of the center of the image.

If there were a program that could run this very simple script, it might draw to the screen the following:

SimpleScriptOutput.png

The good thing about this is that you'll most likely never have to actually look at the script the computer creates, just like you never have to look at the array of pixels and channels that are stored in a photograph. However, if you want to get advanced, that would be possible (and quite a bit easier than editing a raster image). Instead, we will be using tools that convert the things we draw with the mouse and keyboard into one of these scripts that the computer can follow when it wants to re-produce an image to view on the screen (the screen is really just a raster graphic viewer). Then when we are all done, we can have it run the script again to produce another raster graphic that can be saved into a PNG file.

It is also possible for this script to include a certain amount of time to wait before something happens. This allows for animations; some simple examples would be having a stick figure move across the image or having a ball bounce.

One of the very important benefits of vector images is that all the commands for the image are relative.  If you need to increase the size of the image, you just need to change the units that all the commands are applied to.  In the above example, one unit equals approximately 10 pixels, but this could easily be modified so that one unit equals 20 pixels or even 100 pixels.  The image would automatically scale up to the new size without losing any quality, the image will stay crisp and you won't see any pixel artifacts.  This is the opposite of how photos work, there if you were to try to scale the photo up to double or ten times the original size, you would see problems show up in the image. 

Here is an example using our simple image.  In each case, the vector graphic is on the left and the raster graphic is on the right.

One unit equals 10 pixels.
SimpleScriptOutput.pngSimpleScriptOutput.png
One unit equals 20 pixels.
SimpleScriptOutput-Vector2.pngSimpleScriptOutput-RasterScale2.png
One unit equals 100 pixels.   (This one is being scaled back down  to one unit equals 40 pixels by the web-browser to fit to the screen, if you want to see it as full-sized right click on it and view it separately.)

SimpleScriptOutput-Vector10.pngSimpleScriptOutput-RasterScale10.png
You can see that as we talked about in the photos section, the raster graphic doesn't scale up to the large size very well.   However, the vector graphic continues to look smooth and clean at any size. 

In addition to cleanly scaling, vector graphics usually take up less space.  In a raster image, data needs to be stored for every pixel (in three or four channels).  If you have large images, this can be millions of bytes.  Vector graphics on the other hand only store the information necessary to make the shapes and color them in.  For the above example, this is just four commands, each one taking only a few bytes.  There are things you can do to make very complicated vector graphics, but typically they will be much smaller than their raster counterparts.

The other very nice thing about vector graphics is that when you are using graphical programs like Inkscape or Illustrator to edit them, it is very easy to select objects.  For photos we had some real challenges in selecting different objects (like the airplane and the statue's arm).  However, since in vector graphics the commands to create each object are stored, when you click on an object, it is easy for the program to guess which object you are trying to select.  You can then easily modify that object by resizing it, rotating it, or moving it.

File Formats

The primary file format currently in use is SVG or Scalable Vector Graphics (see: http://en.wikipedia.org/wiki/Svg ) which is a type of human readable file called XML (eXtensible Markup Language see: http://en.wikipedia.org/wiki/XML). Although XML and SVG are human-readable, we will not be reading them directly as part of this material. SVG is supported in most vector drawing programs, however it is not yet supported by all web browsers (though this is rapidly changing). If you simply want to use your images on web pages, it is best to convert them to Portable Network Graphics (PNG) which is a lossless raster format.

The other major format for Vector Graphics is the EPS or Encapsulated Post Script. Post Script itself is a file type used for printing (especially industrial printing), and EPS images are built to be easily put inside of a Post Script document. This format has been around a lot longer than SVG, and is supported by many more tools (especially the old ones). Likewise, it is not recommended for use with web browsers.

Inkscape

Inkscape will be the vector editor that we do the majority of our work in, once we have learned the fundamentals here, we will move on to trying the same concepts out in Adobe Illustrator, which is the other major vector graphics editor on the market.  If you don't have Inkscape on your computer, you can get it from our software downloads page.

To start with Inkscape, there are three interactive tutorials that are built in to the program that are very good, and because they are interactive, they are better than just words on paper, so instead of reading what they have to tell you here, lets open up Inkscape and give them a try. 
InkscapeStartup.png
Once you have Inkscape open...

Inkscape Basics

Go to the menu Help -> Tutorials -> Inkscape: Basics.  That will open in a new window and you can read all about (and try out!) panning, zooming, the tools, documents, moving, scaling, rotating, important keys, selections, fills, strokes, duplication, layers, and depth.

Now that we have a grasp on the basics, lets go do an example.  I have prepared a .svg file that can be opened in Inkscape with all the material that we'll need.
BasicScene-orig.svg
BasicScene-orig.png

In this one SVG file there is a background all setup (made up of two parts: the foreground with all the trees, ground, and water; and the background with the sky).  There are also three different components that need to be added in.  The fire and tent need to be scaled down and put in the empty area between the trees.  The mountains need to be scaled up and be put behind the ground and trees but in front of the sky. 

Here's what the finished result will look like.
BasicScene-final.png


Working with Shapes

Once you've mastered those basics, we'll move on to the next tutorial:
Help -> Tutorials -> Inkscape: Shapes
Here we will learn about and try out:
Rectangles (with rounding), ellipses and circles, stars and polygons, and spirals.

Now lets go and try out all the shape tools and many of their different options.  In one Inkscape page, draw the following.
Rectangle: Filled with no stroke, stroke with no fill, fill and stroke, rounded corners, rounded corners and edges.
Ellipse: Ellipse, slice, arc.
Polygon/Star: Polygon, polygon with different number of sides, star, star with offset points, polygon with rounded corners, polygon with randomizer.
Spiral: Spiral, spiral with less turns, spiral that doesn't start from the middle, spiral with faster divergence.

Your page may look something like this:
BasicShapes-final.png

Creative Exercise 1:
Use only the basic shapes (and various fill/stroke colors) to create an image of abstract art.

Creative Exercise 2:
Use the star tool to create a unique pattern.

Paths and Text

Finally, we have one last tutorial that introduces some of the most important concepts:
Help -> Tutorials -> Inkscape: Advanced
Here we will learn about:
Cutting and pasting, free hand drawing, bezier curves, paths and text.

One of the most important parts of this section is working with bezier curves.  To get a little practice, we're going to turn a simple rectangle into a piece of paper that is starting to curl up.   Here's what the end result will look like:
BezierRectangle-final.png

First, download the .svg file of the starting rectangle.

You'll notice that there are a couple of handy nodes about half way down the sides of the rectangle. Let's go ahead and pull both of those nodes to the right (using the node-editing mode). 

Once we've got them out there, we will add some bezier curves into the strait lines.  To do this, hold down shift as you click on one of the nodes, and drag out from it.  That should create a handle for the curve coming out of that point.  Go ahead and do that for both sides of the middle points, and then also to the lines coming down from the two top points.

Once we've got the paper gently curling, lets add some example text.  To do that, we'll switch to the text tool.  Then click near the center of the paper and type whatever text you want to see.  You can change the font size, centering, and font to make it look any way you like.

Now that we've got those basics down, lets use the path tool to make text follow an irregular path through our drawing.

We'll start out by making a simple path with the Bezier Curve Tool.
TextPath-Curve.png

Once we've got the basic shape in, we'll manipulate the curve's handles to smooth it out.
TextPath-Handles.png

Then we'll switch to the text tool and type in some text.
TextPath-Text.png

Now we'll select both the path and the text.
TextPath-Selection.png

With them selected, we'll click Text -> Put on Path.
TextPath-Follow.png

Looking good so far, now we just need to get rid of that line that we have in there.  To do that lets select the line and remove its stroke.
TextPath-Stroke.png

Then finally we're left with just our text.
TextPath-Final.png


Using  Proportions and Space

One of the most important things to think about when creating graphics is if the proportions between the various components of your graphic are correct. 

The most important aspect of proportion is when you are working with a graphic that shows an image of a 3-Dimensional scene (such as the campsite example used above).  When creating a 3-D scene in two dimensions (on the computer screen, or paper) you as the artist need to make sure that the correct proportions are used to accurately represent the scene.  Not accurately re-creating it will cause the people viewing the work to sense that something isn't correct, often without being able to actually identify it, which will lead them to not enjoy the work.  The best way to think about the proportion of 3-D works is to understand that things look bigger when they are closer.  When you are putting together a scene in Inkscape, it is easy to re-size the objects you are working with.  So use this ability to increase the size of close objects and to shrink the size of distant objects, so that they look natural. 

If you look closely at the example of the campground we used above, you'll notice that the trees are smaller in the distance and larger up close.  This was done by using the same tree object, and simply changing the size to match what was needed. 

Lets try that same example now.  Here is the original file, with just the background and example trees.  Copy and paste the trees into the background and change their size to match the correct proportion.  Start in the back with the small trees, then move forward with increasingly large trees.  Don't forget to leave an open area for our campsite.

Background-Empty.svg
Background-Empty.png


Proportion is also used outside of 3-D scenes.  When you simply have text and graphics you need to be aware of the relative sizes between the different objects.  Also, the amount (and location) of open space in the image is very important.

The most common rule used for determining the relative sizes of objects and space is called the Golden Rule or Fibonacci Sequence.  This was developed by the mathematician from Piza, Italy named Fibonacci.  His sequence is simply made where the next number in the sequence is the sum of the previous two numbers.  Starting from 0:1 the start of the sequence is 0:1:1:2:3:5:8:13:21 etc.   Over the years scientists and artists have found that this sequence is everywhere in nature from snail shells to tree leaves.  In addition, the human eye has developed over thousands of years to readily identify this, and objects that are shown in that sequence seem smooth and natural.

In this example on the left the sizes of the text and the spacing between them both follow the 1:1:2:3 ratio.  In this case the font is 20:20:40:60 (from bottom to top) and the spacing is 46:92:138.  In the other example, on the right, the size of the font simply has 20 added each time 20:40:60:80.    You may notice that the one on the left, following the Fibonacci sequence, seems to follow a more natural progression extending up whereas the one on the right seems more abrupt. 

GoldenRule.png               LinearScale.png


The other thing that can be done with space is that it can be used to draw the attention of the viewer in a certain direction. 
EmptySpace.png
Notice how all the empty space inside the box tends to draw your eye down to the red circle?  This can be even more useful in more complicated images with many different objects in them. 

Light and Color

Using Light

As was true with photos, getting the lighting correct is very important for graphics that look good.  However, unlike photos where we had to work with the light that the camera had, where the best we could do was improve it, here we have complete control of how the lighting affects the image.  However, with all that control means that we need to plan ahead and determine what lighting we want, whereas in photos we could just look at what we were given and figure out how to make it as good as it could be. 

Here's an example of an open cardboard box, without any lighting applied.
CardboardBox-unlit.png

And here is that same box, with lighting applied to it.

CardboardBox-lit.png
Its easy to see the difference!  In this case, the author imagined the source of the light to be above and a little to the left of the box.   So you can see the shadow coming down from it and to the right.  Also the right-front face of the box is darker than the left-front face of the box, because some light is on the left-front face, coming a bit from the left side, whereas the right-front face is in the shadow.  Also, the inside of the box is in shadow because the walls are limiting how much light can get in. 
If you look closely you may figure out that there is no way the box could physically be lit like this, the angles of lighting simply aren't possible, but that's not important.  What is important is that there is some aspect of lighting, and that gives the eye enough to separate out the different surfaces, unlike in the first picture.  In graphics, unlike photos, it isn't necessary to make the lighting super realistic, the audience isn't expecting that from graphics, but there still needs to be enough to be pleasing to the eye.

Using Color

When the human eye sees color, it is actually recording electronic waves of light hitting cells in the back of the eye.  A single particle of light is called a photon, and each photon oscillates at a specific frequency, which corresponds to a wavelength.  Photons with a faster frequency (and shorter wavelength), are towards the violet end of the spectrum, while photons with a lower frequency (and longer wavelength) are towards the red end of the spectrum. 
Below is a graphic depicting the spectrum of visible light.
1000px-Inverse_visible_spectrum.svg.png
You may notice that the two ends are dark, these are actually not black, rather they glow just as brightly as all the areas in the middle, but in the infra-red and ultra-violet colors that the human eye cannot detect. 

The colors above are the only colors that the human eye can detect.  You may notice that there are many colors missing: brown, purple, not to mention white, black, and gray.  This is because these colors (and many more) don't actually exist, but we perceive them because of how the photons of light hit our eye.  To learn more about the visible spectrum of light, see this page: http://en.wikipedia.org/wiki/Visible_spectrum   http://es.wikipedia.org/wiki/Espectro_visible

When we see an area that is black, that is because very few or even no photons are hitting our eye from that direction.  On the other hand, when we see the an area that is the color white, we are getting a lot of photons, from every single color hitting our eye at the same time.  Gray is simply in between that, when we see a medium number (too many = white, too few = black) of photons, from all the different shades of light, we will see gray.  All the other colors are found by having photons at two or more different frequencies hit the same part of the eye at the same time.  For instance, if we have two photons of red for every one photon of green (and no other colors), then we will see brown in that area.  If we see one photon of red and one of blue, we will see purple. 

So, brightness of  the color is determined by the total number of photons, and what color we see is determined by what frequency or combinations of frequencies the photons have when they strike our eye.

As we learned in the photo section, when a computer monitor projects light out to our eyes, it is projecting Red, Green and Blue.  These colors can be added together to make all the other colors.  However, when we print an image out onto a piece of paper, the paper isn't projecting light into our eyes like a computer screen is, rather it is reflecting the light in the room.  When we were projecting light, we started with black, and added colors to get the color we wanted...if we wanted to get to white, then we added all the colors.  However, when we talk about reflecting light, we start with a white light, then we start taking away parts of that white light, by absorbing the photons of certain colors, so that only the color we want is still being reflected.  If we absorb all the light and don't reflect any, then we are left with black.  For this reason, printers use the colors Cyan, Magenta, and Yellow for their printing.  Cyan will absorb Red, Magenta will absorb Green, and Yellow will absorb Blue. 
200px-AdditiveColor.svg.png200px-SubtractiveColor.svg.png
For more on reflected or "subtractive" color, see: http://en.wikipedia.org/wiki/Subtractive_color http://es.wikipedia.org/wiki/Síntesis_sustractiva_de_color

As you can see in the images of the box, in the previous section on lighting, the changes in lighting affected the color of the image, and it is important that the colors you use match with the lighting that you are applying to your image.  However, more general color choices also will affect your image.  If you are attempting to create a representation of something real, like a box or a forest, then you need to make your colors close to those of what would be realistic for those objects.  On the other hand, sometimes you are making graphics that don't correspond to something in real life.  For instance, in a logo for a company or the color of text in a banner.  In this case, you need to choose color combinations that work well together and don't clash. 

Unfortunately, colors that do and do not work well together vary by culture.  Colors that go well together in the United States won't work well together in Africa.  The same way, colors that clash in India might work well together in Peru.  To see a quick example of this, look at a sample of flags from different countries.  Each country picks a flag with colors that work well together in that country, but I'm sure you can see some that do and don't look like they belong together in your culture!

flags-a.png

flags-b.png

flags-c.png

That's just the countries that start with A, B, and C and there's already a whole ton of different color combinations.  We could go on for a very long time (which we don't have) on the theories of what colors are good together and which are bad.  Indeed many artists will have to take several classes that revolve around this.  Just keep in mind that there are colors that go well together, and look for them as you create graphics.  It also might be a good idea to ask someone for their opinion of which colors they think will go well together in your graphic. 

Creating a Rocket

So now that we have the basics out of the way, lets try an example of creating a graphic.  For this we will create a rocket using an excellent tutorial by Nicu Buculei which he has graciously made available under the CC-BY-SA license, originally found at: http://howto.nicubunu.ro/rocket-inkscape/

The target here is to produce something like this, not extremely realistic but easily recognizable as a rocket and the most important, fun (hopefully) and easy to create by someone who is using Inkscape for the first time.
rocket.png


So start Inkscape and draw a rectangle, which must be more tall than wide (we are drawing a rocket!) and have straight, not rounded corners.
rocket-01.png

Then select it and convert to path, we will do node editing.
rocket-02.png

Now go in node editor and select the two top nodes. The following operation can be done (as far as I know) only from keyboard: press Ctrl + Alt + > to enlarge the segment, the result should be a trapezium with the big side up.
rocket-03.png

With the same two top nodes selected, add a new node in the middle of their segment.
rocket-04.png

Select the new node (only it) and move it up (keep the Ctrl key pressed to limit the movement to vertical only).
rocket-05.png

Select back the two nodes that were the top corners of the rectangle and make them symmetric, for a shape starting to look like a bullet/rocket.
rocket-06.png

To finish the bullet shape of the rocket body we need to make the bottom edge rounded: select the two bottom corners, add a new node in the middle, select it, move a bit up and made it symmetric, now we have a bullet, an aerodynamic shape.
rocket-07.png

A rocket needs some "wings", so we will create another rectangle, this time much smaller.
rocket-08.png

Select the rectangle and click on it once, this will put in in rotate/skew mode so we need to skew it a bit my dragging on the arrow on one of its edges.
rocket-09.png

Move it in position, next to the rocket body.
rocket-10.png

Again, in rotate/skew mode, rotate it a bit by dragging one of the arrows at the corners, until we like the alignment. Note: no worry if the alignment is not perfect, lower it under the body and when filled with color this won't be noticeable.
rocket-11.png

Select the wing and duplicate it.
rocket-12.png

Flip the new (duplicate) wing horizontally and move it to the other side of the rocket body (keep Ctrl pressed to limit the movement to horizontal).
rocket-13.png

The wing facing us is another thin rectangle, with the same height as the other wings (technically, we should have two rectangles, one for each edge, but for now use one for simplicity). To center the new wing to the rocket body, select it and the body, then use the Align and Distribute dialog to align them horizontally relative to the biggest item (the body).
rocket-14.png

Now you know what is needed for a funny rocket? A window, so the astronauts inside can look at the space. Start by drawing a circle, which will be the windows frame (I think I am boring repeating this, but keep Ctrl pressed, so what you draw is a round circle not an ellipse).
rocket-15.png

Select the circle and the rocket body and align vertically to the center of the body.
rocket-16.png

Another smaller circle will be the real window.
rocket-17.png

Select the two circles and align them horizontally and vertically.
rocket-18.png

Now color the items, using either the color palette at the bottom, the Fill and Stroke button in the toolbar or any of the other possible ways (there are quite a few). A rocket is usually silverish, so use shades of gray.
rocket-19.png

If you want the rocket less realistic but screaming "Fedora", make those grays a bit bluish or go the extra mile and straightly use the Fedora colors (light and dark blue).
rocket-20.png

Back to our rocket, let's make it fly. Take the Bezier tool (pen) and draw freely a few spikes, they will be the flame.
rocket-21.png

Color the flame red or a redish orange and lower it under the rocket body.
rocket-22.png

The core of the flame is supposed to be warmer, so let's draw a new set of smaller spikes in yellow.
rocket-23.png

Optionally, if we want the rocket cruising, not just taking-off, select everything and rotate a bit.
rocket-24.png

Prettyfication

A bit of beautification never hurt, so let's make the rocket a bit more realistic (if you can call that "realistic") and less cartoon. Remove the strokes (for example using the Fill and Stroke dialog) and use silver gradients for all metallic surfaces, do this by using the Gradient tool, dragging and editing colors.
rocket-25.png

Fill everything with gradients, including the flames and the window.
rocket-26.png

Select the inner (yellow) flame and using the Fill and Stroke dialog Blur it a bit for a more realistic (and prettier) look.
rocket-27.png

Blur also the outer (red/orange) flame. And that's about all.
rocket-28.png

Now our rocket can take-of and fly proudly. Go to the stars and beyond them!
http://es.lipsum.com/
rocket-29.png

Congratulations, we've made it through a pretty advanced example from start to finish!

Illustrator

Just as Photoshop has much in common with the GIMP, Illustrator has much in common with Inkscape.  There are a few things that work better in one or the other, but all the important features are very similar. 

Unlike Photoshop, you do not right-click on the items in the toolbox (the ones with a small triangle in the lower right corner) to pop up the other tools.  Instead, you left click and hold down.  After enough time passes, the other tool options will come up.

Lines


ai-PenTools.png
The Pen tool works exactly the same as Inkscape's Bezier tool.  When you click at a new point it makes a strait line, if you then drag it will manipulate the handles to curve it. 
ai-Pen.png

The pencil tool is also similar to the freehand lines too, in that you just click and hold the mouse, and the line follows it wherever it goes.  However, the one in Illustrator is somewhat different because it will automatically make the line into a bezier curve by adding all the necessary nodes and putting their handles at the correct settings. 
ai-Pencil.png

What the pencil tool doesn't do however, is make strait lines.  In Inkscape you can use it by clicking in one point (and letting go of the mouse button), then going to a different point on the screen and click again.  Inkscape with create one solid, strait line between them.  To do this in Illustrator you need to use the line segment tool.  With the line segment tool, you click your start location and hold the mouse button down while you move to the finish location.
ai-LineSegment.png


Shapes

Illustrator has the same standard shapes (Rectangle, Ellipse, Polygon, Star, Spiral) as Inkscape.  The only real differences is that to get a square with rounded edges you use a separate tool, also for the arc you use a separate arc tool instead of just making a segment of an ellipse.
ai-Shapes.png

ai-LineTools.png

Stroke and Fill

The concepts behind stroke and fill in Illustrator are the same as in Inkscape, however, here the tools are somewhat different. 

Here we have the stroke dialog open, and are changing its thickness.
ai-Stroke.png

To quickly change the fill (or the color of the stroke) you can click on the color chooser in the toolbox and it will open the colors dialog.
ai-Color.png

You can switch back and fourth from fill to stroke by clicking the two overlapping boxes.  Then pick the color for each.
ai-Fill.png

If you don't want to have a fill or stroke, select the white space with the red, diagonal line through it.  This indicates none.
ai-NoStroke.png

Just like with the GIMP and Photoshop, you will find that Inkscape and Illustrator have a ton in common, and you can easily apply your Inkscape skills if you ever have to sit down and work at a computer with only Illustrator. (or you could just install Inkscape!)

Diagrams

Sometimes you need to create a graphic that is based on function, and how it looks isn't as important.  Some examples of this might be a chart of an organization's structure or the work flow of a project.  For these, special diagramming software is available that is more suited to the task than a Vector diagram or print layout program.  Two example of these functional diagram programs are Dia (free, open source) and Microsoft's Visio.

The basics of all diagram editors are shapes, connector lines, and text.  Some typical shapes are rectangles, circles, ovals, and triangles.  There can also be more complicated shapes, such as one that looks like a computer or like a house.  There are also several types of connecting lines.  The simplest one can be a plain line, or it can have arrows at one or both ends.  Lines also have different ways they can be connected between the shapes, they can go strait to the destination, they can curve, or they can be routed so that they only go up-do and left-right with only 90 degree turns, they can also be some combinations thereof.  Finally there is text, you can put text within a shape, or elsewhere on the diagram. 
Connectors.png


An example orginizational chart.
OrgChart.png

An example flow chart.
Flowchart.png

In addition to these options, there are several diagram packages out there that allow for creating specialized types of diagrams like software modeling and network organization.  These packages have special shapes and connectors, often ones that will only connect in certain ways.  They are generally tools specifically for use with that skill so we won't cover any of them here.

Dia

Dia is a basic diagram creator.  The above example diagrams were made with it. 

Here's a screenshot of it in action.
DiaBasic.png
The toolbox is on the left side of the screen, there are a few important things to note in there.  There are four rows of buttons on the top.  The buttons in red are used to transform the image, the first button, that looks like an arrow, is used to select and move objects (just like it was in Inkscape).  The tool immediately to its right that looks like a very tall capital 'I', is the text edit tool.  When you have this tool selected and click on a shape, you can then type and the text will show up inside the shape.  You can also use this to edit existing text within a shape.  The tool in that row all the way to the right, that looks like a capital 'T' is the text tool.  This tool allows you to put text anywhere you want on the page. 

The buttons in the green area are used for creating connectors between different shapes.  The first one, by itself on the third row, is the strait line connector.  It will go directly from whichever shape you start at to the shape you end at.  The next one of interest is the second one in on the next row.  It  is the connector that gives you square lines with 90 degree turns.  The last one in the green area is our familiar bezier line creator, it works just like in Inkscape where there are handles for the endpoints that determine how much the line curves.  Once you have put a line in the diagram, you can change things such as its color, thickness, or the arrows on the ends by double clicking on it.

Below the buttons is the area for the symbols.  There are many different sets of symbols included in Dia, in this case we have the "Flowchart" symbols selected.  You can change the set by clicking the dropdown box for the symbols.
DiaShapes.png
Once you have a shape selected, simply go over to the diagram window and click one spot to start it at the upper left corner of where you want it, then drag the mouse down and to the right until the shape is the correct size.  You should be immediately able to type text in it if you desire.  Once you have two shapes in the drawing, you can then use the connectors between them.  Just like lines, you can change the properties of a shape (line color, fill color, text size, etc) by double clicking on it.

Exercise

Use Dia to re-create the example flow-chart.
Flowchart.png

Other Graphic Applications

Publishing Layout

Once you've created a great graphic, you need to find a way to display it to the world.  Sometimes that is done online, but often that means printing it out.  There are a whole class of programs that revolve around making things look good when printed out, called Print Layout, Page Layout, or Publishing Layout programs.  These go beyond the capabilities of typical word processing programs like Microsoft Word, which are generally focused on A5 sized documents.  They allow you to create things like brochures, magazines, books, flyers, etc. 

The most professional tool in this field is generally considered to be QuarkXPress, but Adobe also has its popular PageMaker and InDesign programs.  In smaller companies and in personal use, tools such as Microsoft Publisher and the open source tool Scribus do this work.  

3-D Creation

In this section we only talked about creating graphics in two dimensions, although sometimes we talked about making it look like if it were in three dimensions.  However, all our creations were made to be viewed from one direction and were flat graphics (you couldn't turn them to the side or back).  There is also a whole segment of graphic creation that involves creating things that are capable of being manipulated in three dimensions.  When you have one of these objects, it is possible to spin it around and view it from all angles. 

The two biggest packages for creating 3-D graphics are Blender (open source) and Maya (proprietary).  They are often used to create characters in movies (like Toy Story or Big Buck Bunny), video games, or advertisements.  (More animations with Blender)

In a tangentially related category, are object creation programs.  These can be used to create objects for things like automated milling or 3-D printing. or they can be used to create objects for virtual worlds like Second Life or Google Earth.  The most popular tool that people use for creating these objects is Google Sketchup, however, it is a simplified descendant of industrial strength Computer Aided Design (CAD) programs such as Auto CAD, Solidworks, and BRL CAD.

Animation and Interaction

The use of computers to view graphics over the internet has allowed them to take on a whole new property of interactivity.  Computer driven graphics are capable of performing actions in response to events by the user (clicking somewhere, pushing a key, etc) or simply based on a timer that started when the graphic was opened.  By far the most common way of displaying this content on the internet is through Adobe's Flash Player plugin for web browsers (the Gnash program is a compatible, open source version). 

Because the Flash standard is controlled by the Adobe corporation, there have been two, somewhat joined, attempts to replace it with an open standard in the last couple years.  The first was to build animation capability into the SVG format.  This provides for some of the basic features that the Flash standard supported.  Beyond that the new HTML 5 standard, which all the major browser makers have implemented or are implementing, has numerous animation abilities.  It can deal with SVG files in more advanced ways, it also has what is called a "canvas" element, which creates an area on the page where all kinds of graphics and animation can be shown and manipulated.

Final Exercise

In this several part exercise, we will be creating an advertisement for an imaginary product.

Step One: Make up a product that you want to make an advertisement for.  It can be similar to an existing product, but don't use an existing brand, we want to create something all our own.

Step Two: Determine what message you want the advertisement to say.  Do you want it simply to be a logo or an example of the product?  Do you want to depict the product being used in a certain way? 

Step Three: Produce a layout of the advertisement.  What components do you want where?  Do you want text?  Do you want use some other graphics in your advertisement (if so, find some now)? 

Step Four: Put together the rough advertisement.  At the end of this stage, all the components should be in the correct location and the correct size.  Basic colors should be determined.

Step Five: Touch Up.  How are the lighting effects?  Do you need gradients to smooth things out? 

Step Six: Review.  Have someone else look at your advertisement and tell you what they like and don't like about it.  Go back to step five if necessary, but don't go back any further than that.

Step Seven: Publish.  Create a file that could be distributed on a web site, in print, or on other media.  Possibly upload to openclipart.org. 

Vocabulary

Graphics -
Vector Graphics -
Stroke -
Fill -

Attribution

Mountains, nicubunu, http://www.openclipart.org/detail/9452, Public Domain
Tree 10, nicubunu, http://www.openclipart.org/detail/9487, Public Domain
Tree 9, nicubunu, http://www.openclipart.org/detail/9485, Public Domain
Tree 7, nicubunu, http://www.openclipart.org/detail/9479, Public Domain
Tree 6, nicubunu, http://www.openclipart.org/detail/9481, Public Domain
Tree , nicubunu, http://www.openclipart.org/detail/9469, Public Domain
Fire June holiday's, valessiobrito, http://www.openclipart.org/detail/876, Public Domain
Tente, spadaddin, http://www.openclipart.org/detail/71005, Public Domain
Cardboard Box, molumen, http://www.openclipart.org/detail/1509, Public Domain
Subtractive Color, SharkD et. al., http://commons.wikimedia.org/wiki/File:SubtractiveColor.svg, Public Domain
Gallery of soverign-state flags, wikipedia community, http://en.wikipedia.org/wiki/Gallery_of_sovereign-state_flags, CC-BY-SA
Drawing a rocket with Inkscape is not rocket science, Nicu Buculei, http://howto.nicubunu.ro/rocket-inkscape/, CC-BY-SA

Resources

http://howto.nicubunu.ro/ - Open Source Graphics Tutorials
https://inkscapetutorials.wordpress.com/ - Lots of Inkscape Tutorials
http://kalaalog.com/2007/09/27/how-to-illustrate-palm-tree/
Start of a series of inkscape tutorials - http://www.youtube.com/watch?v=h-zLZ6ilRRE
Start of a series of illustrator tutorials - http://www.youtube.com/watch?v=2uAzk_hLRow

TODO:
Create exercise with golden ratio
Create exercise with empty space
Create exercise with light source
Create exercise with color