Digit 2005-04 - Clevernotions.com

you can draw a mask to isolate
them from the background.
The masks are simple polygonal
shapes that you draw over the footage.
They can be animated, both in translation
and in shape. The masks are autokeyframed
as you make changes to
them, so it’s a relatively straight-forward
process to matte out a particular object
from the tracking process. Multiple
masks can be added and animated
independently, so it doesn’t matter if
objects cross each other in the footage.
Boujou also allows you to import imagebased
masks so you can create custom
mattes from the footage using whatever
motion graphics application you like.
Once objects are masked out, you
can tell Boujou to track the scene, which
it does quickly. The speed will depend on
the number of tracked points, length of
the sequence, and the degree of camera
movement. If there is a big jump between
frames then tracking can take longer.
Generally, Boujou suffers less from losing
track of points than other matchmoving
applications, and the integrity of the
solutions seems to be high.
Some sequences will prove too
difficult, in which case you can manually
intervene and place custom markers,
or inset survey data to constrain the
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solution. Of course, entering the camera
focal length helps.
Once tracked, the camera solution
is derived when you press the Camera
Tracking button. This runs in a separate
pass and can take a minute or so. Again
solution integrity tends to be high, and
you can place test 3D geometry in the
scene to confirm the solution looks
good. Boujou allows you to export
the camera to numerous 3D formats
including Maya .ma, Softimage .xsi,
LightWave .lws and Houdini .hip.
You can also export to Shake.
The new version sports a charcoal
interface for enhanced contrast and
new, faster tracking algorithms. There
are some improved tweaking tools,
such as camera path smoothing,
and a new timeline.
Redundant Wizard
A new Wizard is included to guide users
through the whole matchmoving process.
This is a godsend for those not used to
the program, though the process is so
simple you’ll only need to use the Wizard
a few times before you get the hang of
it. We did encounter a windowing bug
requiring a Force Quit on Mac OS X,
where two Save dialogs overlapped each
other during a camera export and neither
would receive mouse or keyboard input.
Apart from this the program seemed
fairly robust and bug-free.
Boujou is what an automatic
matchmoving program should be.
It’s simple to use and gets the job
done quickly with the minimum of
fuss, saving a huge amount of time
in the process. For those who can’t
stretch to the price tag, the strippeddown
Boujou Bullet offers some of the
power of the full version for $2,500. But
despite the price, Boujou 3.0 is a superb
program that’s well worth looking into.
Simon Danaher
1. Boujou has an easy
to use lens distortionfactoring
tool that
allows you to calculate
the distortion in your
footage if you don’t
know the value.
2. 2D feature
tracking of a 280frame
sequence took
around two-and-a-half
minutes on a Dual 1.8
G5, and extracting the
camera solution took
only one minute.
3. Polygon masks are
used to isolate moving
objects from the scene
that would otherwise
contaminate the
tracking process.
4. The solution can
be previewed in 3D
before export, and
3D test objects can
be inserted.
5. A new Wizard
guides you through
every aspect of the
tracking process.
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