Illustrator Paths : II

this is a continuation of a discussion started in Illustrator Paths : I, which covered two important facts about drawing vectors. this post will touch on how to anticipate the shape of a curve and drawing economically.

when drawing with the pen tool it can be handy to use a driving analogy — the direction you pull the control point equals the direction of the vehicle (that’s pretty obvious), the distance you pull that control point equals your speed. the three curves below use the same two anchor points and only one control point. the direction of travel is the same for all three, but the speed varies. the first is traveling faster and has to travel further before turning sharply to get to where it’s going. the last one is traveling slower, so can make a more gentle turn :
screen grab show three different curves
direction and speed — you are controlling only two things every time you pull out a control point. but what a lot of variation you can get between two anchors with just one control point :
screen grab of three more open curves
you might prefer the rubber band analogy — direction and stretch — same thing :
screen grab showing three more curves using only one control point

now, these are the simplest curves possible — two anchor points and one control point. but any one curve can have two control points — that’s two directions and two speeds interacting with each other — giving us quite complex curves from just two anchors :
complex curves from just two anchor points
join those two anchor points together and you get quite complex shapes :
screen grab showing complex shapes from just two anchor points

and that’s the main lesson for this post — you can get quite complex curves and shapes from very few anchor points. and fewer anchors generally means more beautiful curves.

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Illustrator Paths : I

this is the first of a few posts dealing with drawing vectors in Adobe Creative Suite — which really isn’t as difficult as some appear to find it.

these posts are more about understanding the mechanics of vectors — for the very basics on drawing with the pen tool see Adobe’s site.

let’s start with some observations about curved paths : when you draw a circle with the ellipse tool (holding down shift constrains the dimensions to a circle) you get four anchor points. each anchor point has a pair of equi-distant control points :
screen capture of circle path

delete two of those points and you’ll get an ellipse with anchor points at either end. again the control points are equi-distant from their anchor points — that’s what makes the ellipse symmetrical. with a bit of experimenting you’ll find that you can make exactly the same shape with anchor points on either side instead. what does this show? … that there is generally more than one way to create any given curved shape (note: this is important fact number one).screen grab of elliptical pathscreen grab of second elliptical path

a seriously under-utilised feature of vectors in CS is that you are not restricted to just adjusting anchor and control points — you can also drag the path segments themselves. take that first ellipse and drag the sides out and you’ll find you can create a circle (maybe not exactly perfect, but so close to perfect that it doesn’t matter). this demonstrates important fact number two : any one anchor point can describe a curve up to 180 degrees :
screen grab of 2-point circular path

fully understanding the implications of these two important facts will lead to more efficient curve drawing (fewer anchor points equals more beautiful curves), and a greater love of vector drawing generally :
screen grab of heart shaped path

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