Real World Computing

Tom Arah explains how to tap into Adobe Illustrator's hidden creative depths and discover the creative richness vector drawing has to offer.

Ten years ago, today's market leader Adobe Illustrator was hopelessly underpowered compared to rivals like Xara and Expression (see last month's column), unable to produce work with the same creative depth. Despite its name, it wasn't much good for illustration. Many people still see vector drawing as clinical, lifeless and too obviously computer-generated, but these days that perception is mistaken. With a little effort, Illustrator CS3 (free trial from www.adobe.com/downloads) can be creatively exciting, especially with a little help.

To understand why Illustrator drawings look clinical and lifeless, draw a simple circle, scale it up and zoom in on its edge - even at maximum 6,400% magnification, the circle's boundary will be razor sharp, because it was generated from a mathematical vector rather than stored as a fixed-size bitmap. Illustrator graphics are resolution-independent PostScript descriptions that can be output pin-sharp at any size. Such sharp edges may be perfect for high-resolution scalable type, but for creative drawing and painting you want variable-width strokes and fuzzy textured fills with the ability to integrate bitmapped images, which wasn't in Adobe's brief at all. Illustrator's great strength lay in vectors and nothing must compromise its EPS (Encapsulated PostScript) output quality.

However, PostScript's filled shapes and stroked paths can produce rich illustrations if you learn to think laterally and, as Illustrator does, in terms of vectors. That flat circle can become a realistically shaded ball by simply applying a vector-based, mathematically defined elliptical gradient fill. Such linear and radial gradient effects are still clinical, but vectors can produce more flexible formatting: another way to shade that ball is by drawing a second, lighter overlapping circle offset from the centre, then select both circles and use the Blend command to create an illusion of three dimensions. The Object | Expand command will let you break down this smooth shading into multiple intermediate shapes and shades (255 by default), and using multiple coloured objects this way allows you to produce remarkably subtle shading.

Once you get into a vector frame of mind, a whole range of more advanced effects becomes possible. An outlined ellipse with uniform line-width screams out its vector origins, but the Expand command lets you turn the stroke into a filled shape, then use the Direct Selection tool to move the outline's defining control points to make the stroke appear more fluid. Illustrator even offers a dedicated Tweak filter for manipulating multiple nodes simultaneously (deselect the Anchor Points option to keep the effect smooth). The ellipse ceases to look scientifically precise and begins to look less perfect and more human.

Similar lateral thinking can produce vector versions of the most common formatting effects. For example, while only solid or gradient fills can be applied to an object, there's nothing to stop you building more advanced fills using multiple objects: create a variety of coloured circles, drag them onto the Swatches panel and you can instantly apply this new polka-dot pattern to any object. To produce a drop-shadow effect, simply offset a duplicated version of the circle, darken it and send it behind the original. To create a basic transparency effect - say, for a logo - overlay two different coloured filled circles (no outlines), copy and paste them in front , then on the Intersect option in the Pathfinder palette to create a new object over the overlap. In the Color palette, you can then mix and apply a CMYK colour midway between the two to yield a 50% transparency effect.

Continued....