Figure 8.19.
This tool fills the selected area with a gradient blend of the
foreground and background colors by default
This tool fills the selected area with a gradient blend of the
foreground and background colors by default, but there are many
options. To make a blend, drag the
cursor in the direction you want the gradient to go, and release
the mouse button when you feel you have the right position and
size of your blend. The softness of the blend depends on how far
you drag the cursor. The shorter the drag distance, the sharper it
will be.
There are an astonishing number of things you can do with this
tool, and the possibilities may seem a bit overwhelming at first.
The two most important options you have are the Gradient and the
Shape. Clicking the Gradient button in the tool options brings up
a Gradient Select window, allowing you to choose from among a
variety of gradients supplied with GIMP; you can also construct
and save custom gradients.
For Shape, there are 11 options: Linear, Bilinear, Radial,
Square, Conical (symmetric), Conical (asymmetric), Shapeburst
(angular), Shapeburst (spherical), Shapeburst (dimpled), Spiral
(clockwise), and Spiral (counterclockwise); these are described in
detail below. The Shapeburst options are the most interesting:
they cause the gradient to follow the shape of the selection
boundary, no matter how twisty it is. Unlike the other shapes,
Shapeburst gradients are not affected by the length or direction
of the line you draw: for them as well as every other type of
gradient you are required to click inside the selection and move
the mouse, but a Shapeburst appears the same no matter where you
click or how you move.
Tip
Check out the Difference option in the Mode menu, where doing the
same thing (even with full opacity) will result in fantastic
swirling patterns, changing and adding every time you drag the
cursor.
3.3.1. Activate Tool
The Blend Tool can be called in the following
order, from the image-menu:
Tools/
Paint Tools/
Blend.
The Tool can also be called by clicking the tool icon:
3.3.2. Key modifiers (Defaults)
Shortcut
The L
key will change the active tool to Gradient Fill.
Ctrl
Ctrl is used to create straight lines that are
constrained to 15 degree absolute angles.
3.3.3. Options
Overview
The available tool options can be accessed
by double clicking the Gradient Tool icon.
Opacity
The Opacity slider sets the transparency level for the gradient. A
higher opacity setting results in a more opaque fill and a lower
setting results in a more transparent fill.
Mode
The Mode dropdown list provides a selection of paint application
modes. A list of these modes can be found in the
Glossary.
Gradient
A variety of gradient patterns can be selected from the
drop-down list. The tool causes a shading pattern that
transitions from foreground to background color or introducing
others colors, in the direction the user determines by drawing
a line in the image. For the purposes of drawing the gradient,
the Reverse checkbox reverse the gradient
direction with the effect, for instance, of swapping the
foreground and background colors.
Offset
The Offset value permits to increase the
"slope" of the gradient.
Shape
The GIMP provides 11 shapes, which can be
selected from the drop-down list. Details on each of the
shapes are given below.
Linear
The Lineargradient begins with
the foreground color at the starting point of the
drawn line and transitions linearly to the background
color at the ending point.
Bi-Linear
The Bi-Linear shape proceeds in
both directions from the starting point, for a
distance determined by the length of the drawn line.
It is useful, for example, for giving the appearance
of a cylinder.
Radial
The Radial gradient gives a circle,
with foreground color at the center and background color
outside the circle. It gives the appearance of a sphere
without directional lighting.
Square
There are four shapes that are some variant on a
square: Square,
Shapeburst (angular),
Shapeburst (spherical), and
Shapeburst (dimpled). They all
put the foreground color at the center of a square,
whose center is at the start of the drawn line, and
whose half-diagonal is the length of the drawn line.
The four options provide a variety in the manner in
which the gradient is calculated; experimentation is
the best means of seeing the differences.
Conical (symmetric)
The Conical(symmetrical) shape
gives the sensation of looking down at the tip of a
cone, which appears to be illuminated with the
background color from a direction determined by the
direction of the drawn line.
Conical (asymmetric)
Conical(asymmetric) is similar to
Conical(symmetric) except that
the "cone" appears to have a ridge where the line is
drawn.
Spiral (clockwise)
The Spiral tools provide spirals
whose repeat width is determined by the length of
the drawn line.
Repeat
There are two repeat modes: Sawtooth Wave
and Triangular Wave. The Sawtooth
pattern is achieved by beginning with the foreground,
transitioning to the background, then starting over with the
foreground. The Triangular starts with the foreground,
transitions to the background, then transitions back to the
foreground.