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Photoshop 7's new Brushes palette is far more
than simply a place to pick a brush. You have incredible control
over the size, shape, and behavior of the brush. In this column,
we'll look at the Shape Dynamics and the Scatter panes of the
Brushes palette.
SHAPE DYNAMICS
The Shape Dynamics pane of the Brushes palette controls three
aspects of the stroke appearance: size, rotation, and
perspective. The variations for each parameter are specified
with sliders.
The Shape Dynamics settings are:
• Size Jitter - This slider determines how much variation there
will be in the individual instances of the brush's tip. At the
maximum of 100% variation, instances of the brush tip can be as
small as 10% (or smaller) of the diameter that you have set. In
no case will Size Jitter create instances of the brush tip
larger than the Diameter selected in Brush Tip Shape or the
Master Diameter selected in Brush Presets.
• Minimum Diameter - You can constrain the size
of the smallest instances using the Minimum Diameter slider.
• Tilt Scale - When the Control pop-up menu is
set to Tilt, this slider regulates how much the angle of the
stylus will affect the brush stroke.
• Angle Jitter - With non-round brush tips, the
angle of application can be varied. The Angle Jitter setting
determines the degree of variation. At a setting of 25%, the
orientation of the brush tip with vary from -90 degrees to +90
degrees Remember that, by default, the angle is relative to
orientation of the page rather than the path of the stroke -
even if you drag a circular stroke, the variation in angle
remains relative to the top of the image. Orient the brush tip
to the path by changing the Control menu under Angle Jitter to
Direction. (You don't need to change the Angle Jitter from 0%.)
• Roundness Jitter - The Roundness slider
controls variation in the proportion of a brush tip. When set to
0%, each instance of the brush has the same width-to-height
relationship. As you increase Roundness Jitter, you add
variation. At 100% jitter, the height of the brush instances
will vary between approximately 5% and 100% of the size
specified in the Brushes palette. Roundness never increases the
height beyond that selected with the Diameter or Master Diameter
sliders.
• Minimum Roundness - You can constrain the
Roundness variations using this slider. It sets the smallest
instance that the brush will produce when Roundness Jitter is
activated.
Examples of the shape dynamics are shown here.
For ease of identification, custom brushes were defined using
numerals. In all cases, Spacing was set to 110%.
• Number 1: The stroke has no shape dynamics
applied.
• Number 2: Size Jitter is 50%.
• Number 3: Size Jitter is 100%.
• Number 4: Size Jitter is 100% combined with a
minimum diameter of 50%.
• Number 5: Angle Jitter is set to 10%.
• Number 6: Angle Jitter is 50%.
• Number 7: Roundness Jitter is 50%.
• Number 8: Roundness Jitter is set to 100%,
with a Minimum Roundness of 20%.
Note the difference between Roundness and Size
jittering. With Roundness, the width of each brush instance
remains the same - only the height is varied. When working with
the dynamic brush options, think of the slider as representing
the amount of variation or variety or change in the individual
brush instances along the stroke, and the pop-up menu as the
control for that variation. Combining Shape Dynamics settings
produces more complicated patterns. However, once you understand
what each option does, their interaction is more predictable.
This stroke was created with the settings shown.
SCATTERING
Scattering spreads copies of the brush tip as instances along
the path of the stroke. The next image illustrates how Spacing
affects Scattering and shows the influence of the Count and
Count Jitter options.
In this image, the following settings are used:
1. Spacing 25%, Scatter 220%, Count 0, Count Jitter 0%.
2. Spacing 100%, Scatter 220%, Count 0, Count
Jitter 0%.
3. Spacing 100%, Scatter 220%, Count 3, Count
Jitter 0%.
4. Spacing 100%, Scatter 220%, Count 3, Count
Jitter 60%.
Using Spacing to create a specific density of
brush instances results in substantial overlap in places, as
well as some areas of "clumping," where many instances occur in
a small space. Using the Scattering and Count options,
especially in conjunction with Count Jitter, produces the
appearance of random distribution, while doing a better job of
preserving individual brush instances.
The Scattering pane of the Brushes palette also
offers the check box Both Axes. In the first set of examples,
only one axis is used for distributing the brush instances. The
scattering is perpendicular to the path. Adding the second axis
enables you to randomize the scattering along the path as well.
These five examples, all set to Spacing 100%, do
not use the Count option in order to better display the effect
of adding a second axis of distribution. The settings used in
image are:
1. No scattering.
2. Scatter 100%, one axis.
3. Scatter 100%, both axes.
4. Scatter 250%, one axis.
5. Scatter 250%, both axes.
Enabling the Both Axes option produces a result
much like using a reduced Spacing setting - some clumping of the
brush instances occurs as the distribution is varied along the
path of the stroke.
TIP: When Count and Count Jitter are used and
Scatter is set to Both Axes, a very random pattern can be
produced, but you're likely to see brush instances bunched
together in groups. Add some Roundness Jitter (Shape Dynamics)
to produce an illusion of depth. |