# What is Vector Illustration?

## 31 Aug What is Vector Illustration?

Have you ever wondered what are Vector Illustrations and what differentiates them from other digital illustrations made in software such as Photoshop? The concept of Vector Illustration is a tad difficult to grasp when we encounter it for the first time… and it is very possible you’ll get discouraged and decide that “vector” is not your thing.

Well, worry no more! In this post I will tell you all you need to know to become truly passionate about this fascinating concept and become an expert in no time!

### WHAT ARE VECTOR ILLUSTRATIONS?

Vector Illustrations are drawings that are made by using a computer software. They are formed entirely of Mathematical Operations, such as vectors, coordinates, ratios, angles, lines, Bezier curves, etc…

These kind of illustrations are done not by freehand sketching in a paper–like the traditional illustration–but carefully crafted in the computer by using special software and vector tools.

They are composed of forms and outlines, that when combined and arranged in a specific manner, will generate unique graphic effects. These illustration conserve the Mathematical Base they have been built with; which allows them to be manipulated and scaled without losing any resolution whatsoever.

Whereas a Painting Software–such as Adobe Photoshop–would create a circle in the manner of a group of pixels; a Drawing Software–such as Adobe Illustrator–will draw the circle with a Geometric Operation, by defining its position in space by (x,y) coordinates and a given ratio r.

Images in a Paint software are made of pixels. Vector illustrations are made of geometric operations

With these geometric parameters, we will achieve a perfect representation of a circle every time, no matter how much we scale the drawing.

This method of generating form is the principal advantage of vector illustrations, but it also creates some limitations.

Vector images allow us to create graphic objects with different contour lines and color fills. The shape can be drawn in a very precise way, and every object can be handled independently to the rest, since each object is formed by an unique mathematical formula.

Each vector object:

• Have a contour line and a fill of choice. The contour (or outline) and the fill can be changed at any given time.
• Can be grouped, separated, merged, cut, intersected… and they can interact with any of the other vector objects in the drawing in various ways.
• If it is independent of the rest, it can be handled separately.
• Can be arranged and moved up or below the other vector objects at any time.

It all may seem very complicated at first, but the truth is that drawing vector illustrations is quite simple really–thanks to the User Interface that the Drawing Software offers the designers.

### Pure Math: An example of Vector Code

The following script shows an example of how the computer stores and reads the vector elements drawn by the user in the Drawing Software. This example is the script to draw a Bezier curve:

/* Script for generating a Bézier curve */
typedef struct {
float x;
float y;
}

Point2D;
Point2D PointOnCubicBezier( Point2D* cp, float t ) {

float ax, bx, cx;
float ay, by, cy;
float tSquared, tCubed;
Point2D result;

/* cálculo de los coeficientes polinomiales */

cx = 3.0 * (cp[1].x – cp[0].x);
bx = 3.0 * (cp[2].x – cp[1].x) – cx;
ax = cp[3].x – cp[0].x – cx – bx;
cy = 3.0 * (cp[1].y – cp[0].y);
by = 3.0 * (cp[2].y – cp[1].y) – cy;
ay = cp[3].y – cp[0].y – cy – by;

/* calculate the curve point at parameter value t */

tSquared = t * t;
tCubed = tSquared * t;
result.x = (ax * tCubed) + (bx * tSquared) + (cx * t) + cp[0].x;
result.y = (ay * tCubed) + (by * tSquared) + (cy * t) + cp[0].y;
return result;

}
/* ComputeBezier fills an array of Point2D structs with the curve points generated from the control points cp. Caller must allocate sufficient memory for the result, which is <sizeof(Point2D) numberOfPoints> */
void ComputeBezier( Point2D* cp, int numberOfPoints, Point2D* curve ) {

float dt;
int i;
dt = 1.0 / ( numberOfPoints – 1 );
for( i = 0; i < numberOfPoints; i++)
curve[i] = PointOnCubicBezier( cp, i*dt );

}

The resulting curve can be drawn tracing lines from point to point in the curve’s matrix. The higher the number of points, the softer the curve will be.

### Pros & Cons

After seeing how the Vector illustrations are formed, it becomes clear what it’s Pros are:

• The size in which we start the drawing doesn’t matter. We can scale the drawing up or down and it will never lose resolution.
• Each object will be defined by its own mathematical formula, and will always be independent from each other. They can be scaled, distorted and moved without affecting the other elements of the drawing.
• A drawing can be reused from one project to the next.

• We can easily control the shape, rotation and hierarchical order of the elements of the drawing.
• All the effects applied to the object can be edited at any time. The drawing is always editable.
• The file size is usually very small, since it only has to store the mathematical code of the drawings as a plain text.
• The vector objects can be interpolated with a given number of steps; being able to make a shape transition between a cube and a sphere in 10 steps, for example.
• Vector illustration allows for the manipulation and creation of types and fonts. The fonts Type1 and TrueType are actually vector objects, and can be handled accordingly.
• The clipart is also vector, being EPS the most common type of file format.
• A vector illustration can also include bitmaps and raster images. They can be used as fills or as separate composition elements. The vector illustrations can also be turned into raster; and can be saved as GIF or JPG.

The Pros & Cons of vector illustration

The main limitations or Cons of vector illustrations are usually their cold and computer-generated look, with an uncanny perfect contour [1]

This problem can often be fixed–especially in the latest Software versions–by using irregular contours and special effects that simulate traditional painting techniques [2]

There are also a big array of line styles that can be applied to the vector contours, that imitate real world media such as paintbrushes and ink pens [3]

For example, we can add to the vector contour a drawing of a rope or a chain, to make it look more interesting.

Some Software solutions can also make repetitions of other vector objects along a stroke: For example, we can add the footprints of a dos, or a line of ants [4]

A big Con is that in vector illustration it becomes very hard to obtain photorealistic results; and to be able to get them, one must be able to perform very complex gradients, meshes, color superpositions, etc… that make the vector file become very heavy for the computer’s processor. [5]

### Uses of the Vector Illustrations

As we’ve seen over and over, vector image’s biggest asset is their capability to be scaled without losing quality.

This format is usually used for making images that have big colored regions of one uniform color and are delimited by a closed outline–perfect for graphic design elements.

The most common use for vector illustrations are anagrams and logos; because they can be scaled in many varied sizes such as business card and hoardings.

But vector illustrations are also used for many other purposes.

Most of the times, vector illustration is used combined with photos in raster mode to make product images–such as packaging design, product commercials, magazine ads–or simply in the creation of cool collages [1]

Vector illustration in graphic design

Vector tools such as the Pen Tool are also very popular for making digital retouching; thanks to their clean contours [2]

Vector illustration for photo retouching

It is also very common to see vector illustrations in the television spots, flash animations for the web, cartoons, etc…

They are used to build digital marionettes of the cartoons, since their vector parts can be very easily animated and moved [3]

Uses of vector illustration

Vector illustration is extensively used for product merchandising, such as notebook designs, coffee cups, book covers, etc… [4]

Even textile companies make their designs with drawing software solutions, because they provide very easy methods of creating seamless patterns and tiles.

Las compañías textiles emplean el dibujo vectorial para la creación de estampados de las telas, así como los diseños de los bordados.

Software such as Corel Draw, have included in their latest versions a plugin to generate embroidery effects by using vector illustrations [5]

Fashion designers use these methods as well, to draw their model designs [6]

Vector illustration in fashion design

But vector illustration is not just for 2D uses!

[7] – 3D model of a Sword generated by using a vector contour

As I mentioned in the first post about the Origins of Vector Illustration, vectors and Bezier curves have their origin in the CAD software.

3D Software such as 3D Studio Max can import vector drawings in AI or EPS formats, and use them to extrude and model extremely complicated shapes in 3D, such as the blade of this sword [7]

This kind of software also store the (x,y,z) in space of the vertex and edges that conform the 3D shapes, just like vector illustration software does in a 2D space!

### Other Uses: Types

Illustration software usually works hand in hand with typography creation software.

This is understandable, since both software solutions work with vectors, and the fonts Type1–as well as the graphics that can be done in Illustrator (AI/EPS formats)–are all based on Postcript.

For this reason, it is super easy to make the glyphs and typos inside an illustration software (such as Illustrator) and export them as an EPS into a font creation software such as Fontographer.

Types can be converted into Vectors to edit them for logos or for developing new types

Another advantage, is that we are able to turn any given font into vector outlines, that can be edited just as any other vector object would.

The illustration software has an option to Create Outlines out of the fonts. By doing this, one can easily make edits  to develop interesting logos, or even new fonts!

### Coming up Next

In the next post, We will embark into the world of vector illustration by reviewing the User’s Interface of the Adobe Illustration CS5.

Don’t miss it!

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