Animated Brushes
The next step is of course, the Animbrush. Instead of using
just a single image as part of the brush, let's use several images,
e.g.
from a image file sequence, or from an animation made right in
Dogwaffle.
Imagine you have a small image made in optipustics showing grass or
bushes growing one way, then another image growing another way, or with
slightly different colors, and a third one yet again slightly
different.
You can load the image sequence through the Animbrush menu. At that
point, if you draw something using this brush, Dogwaffle will cycle
through the images and apply them in sequence. Thus, rather than seing
the same brush image applied , you'll see an alternating effect which
creates a cumulative collection of various brushes. This is great for
wild savannah grass, pebbles of different rocks at the beach,...
Here are some examples of things you can do with that.
In the following example, several basic images from optipustics presets
like Dogwillow, Broccoli Trail and others were used to make a few
images. Once they were loaded into the Animbrush, a single stroke
roughly along
a circle drew all this:
In Matte mode, changing parameters like opacity or color, or both, can
create thick brush effects with lots of different orientations of the
branches. In fact there are only a few images needed in the Animbrush.
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An Example: Making a Custom AnimBrush
Let's go into more details. For example, let's start with a new, square
320x320 buffer. Then create a new animation from the Animation/Create...
menu and make it a 4 frames animation. Open the Optipustics panel from
the Windows menu, enable it, and select the Dogwillow
preset.
Then draw a short bit of Dogwillow into frame 1 of the animation.
Advance
the counter to the next frame, and draw another piece of Dogwillow into
it.
Advance to the next frame,etc until you have all 4 frames painted with
different
dogwillow images. You could also change colors or contrast or apply
other
filters to each frame to further vary their appearance.
Perhaps you'll have a sequence of images like these:
While these images are still in the animation, do the following to
transfer the images into the Animbrush:
- Set the slider in the animation controls to the left
(first frame, number 0). Or, if you want to skip a few first
frame(s)
you can place it between the first and last frame. Only the
frames
from the current to the last would be loaded into the animbrush in that
case.
- click the custom brush selector as usual like you
would for selecting a regular (static) custom brush. Remember its
normal use: click-and-drag a rectangular area from the current image in
the buffer. That selection gets loaded into the brush.
- Press down and hold the ALT key as you get ready
to click-and-drag the first corner of the desired area in the current
frame of the animation. This could be near the lower-left or upper
right corner for example. Note: if you don't hold the ALT key down at
the time when you click-and-drag, then only the current frame's image
is used. This is the
normal custom brush selection mode. So be sure to have the ALT
key
down at the time you click-and-drag. Don't release the mouse button yet.
- While still dragging the mouse to set the final size of
the custom selector's rectangular region, you can temporarily
release the ALT key, so that you can use the LEFT/RIGHT arrow
keys
to cycle through the frames in the animation while still deciding where
to release the selector. This will allow you to verify that all frames
are
contained in the selection you're about to make. Be sure to use the
LEFT
arrow keys to return to the first frame before you finish.
- If you did let go of the ALT key temporarily, press
and hold the ALT key it again, then release the mouse.
If you did not let go the ALT key, it should still be pressed
down and you can release the mouse now. Either way, this finishes the
selection.
- Dogwaffle will go through each frame of the animation,
starting from the first frame you started with, and grab a copy of the
frame which is inside your selected rectangular region. You can tell
that it's grabbing each frame because it's showing it in a visual
feedback in the animation buffer.
Next, it's a good idea to do a test: paint with that animbrush into the
current buffer. (You can use 'u' to undo that test drawing, if you need
to reuse the animation). If it shows that the custom animbrush
selection was successful and it's drawing with the intended images from
the animation's frames, go to Brush/AnimBrush/Save... and save
the animated brush to
a .anb file.
If you find that the images in the brush are too big, you can use Brush/Resample
to resize the brush, even if it's an animated brush.
If you're going to use this animbrush later and want to temporarily
store it, so as to have it readily available amongst other custom
brushes, select the Brush/Animbrush/Store... option
You can then just click the Restore option in the
floating, stored image, to make it the current brush again.
This is, by-the-way, a neat feature: while a stored regular custom
brush appears as a still image, you will see this one, the animated
brush, cycling gently through all its images to remind you that it's an
animated brush.
Chroma Keying
You'll also notice that the above brush got keyed onto the white
background
(default) for the transparent part. It basically does chroma
keying
on a brush, making the 'key' part of the brush. It's used to
remove
certain colors from a brush and leave those areas transparent. If you
start
from a picture taken out in the nature, you can eliminate unwanted
colors,
such as unwanted shades of green from the leaves and grass around a
flower,
or blue if the picture was taken against the sky with clouds.
Here, a brush is selected and the blue part is made transparent.
Adjusting the high pass helps fine tune how much of the blue is removed.
Technically, the difference of the selected color and each pixel's
color
is pushed through a lookup table defined by the low clip and high pass
scrollers,
to get the final key.
When 'use alpha if active' is selected, the alpha channel will define
the
brush's key instead of a color (when the brush is picked up).
Using the Custom AnimBrush
Ok, now, that we've created an Animbrush, let's use it.
For example, as we click a few individual impressions with the brush,
each image gets painted into the buffer:
After a few clicks the first image re-appears. You'll notice that each
of the 4 frames in the animated brush are used, one-by-one. Also notice
that these brushes come with full Alpha and can thus be overlapping and
blended together. You can further change parameters in the Brush
controls
now.
Let's change the stepping factor (Step) in the Brush panel, to reduce
the impressions as we freely paint with this brush, so they are not too
close together and not too cluttered.
This is fun to create greeting cards. The following too just a single
stroke:
In addition to the Stepping, we can change the Opacity. We can also
switch from Color mode to Matte mode, change the size (resample) for
parts which are farther away or closer. Perhaps we start with a very
light amount, and gradually get more opaque. Then we can add a few lens
flares (Radiant plugin), Novae, Light diffusion, blur filters or other
effects.(all directly from
Dogwaffle).
More fun ...
Animbrushes are fun with static images, but they're even more powerful
with animations. You can for example load a sequence of a bee in 3-4
different poses into an animated brush, and then paint it across a
path. If you combine this with the Stroke player into an animation you
can quickly create animations like the ones shown here.
Once they're loaded into the Animbrush, you can change some parameters
such as enable PostFX shadows and resample the brush for various sizes
to quickly create an armada of killer bees.
Or, you can use the Stroke player to force the bees into the frames of
an animation.
Stay tuned for more examples
to come...
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