Graphics Programs Reference
In-Depth Information
F
IGURE
5-1
Use transparency in
combination with fills to create a
vector composition that
looks
like
you used a paint program.
of them. A curve can usually be described as a beginning point
and an end point, with some sort of influence over the shape
(or it would travel in a straight line). The two most common
influences that shape a curve are called
bias
and
tension
:
N
Bias
The preference of one side over the other, similar
to what we see in politics. With curves, Bias determines
whether the curve slopes toward the beginning point or
the end point.
Tension
N
Think of a rope being held by two children
(or adults). When there is tension, there is a close
adherence to a straight-line vector between one end and
the other. Without tension, the curve deviates away from
the straight-line vector; the rope sags toward the ground.
Bias and tension are shown to you every time you create
a curve in Xara Xtreme. The control handles for the curve
determine bias when you drag, for example, the end-point
control handle toward the curve segment. Tension is created and
released as you move the control handle away from the curve
itself. Similarly, a gradient by default travels linearly, and here's
where Profiles change this, and all you need do right now is
