Graphics Programs Reference
In-Depth Information
Note
Keep in mind that every time you move an image around, some fil-
tering occurs. Filtering means a kind of little blur that degrades the
image a little. Moving an image twice like this creates two levels of
filtering. Doing that a lot will in effect soften your image. On occa-
sion this is a must, but in general you should avoid it. Here it served
as a good way to show both stabilizing and match-moving together.
29. Double-click Tracker2 to open its Properties panel.
30. Click the Transform tab and choose Match-move from the Transform drop-down
menu.
31. Make sure you're viewing Tracker2 in the Viewer.
32. Click Play in the Viewer.
You can see that the motion data was returned as it was before, except now it has
flares, which are weaving just like the rest of the picture.
33. Save your project in your student_files directory with a name you find fitting.
34. Press Ctrl/Cmd-W to close the Nuke script and create a fresh one.
Next you will go deeper into tracking.
Tracking Four Points
In this section you track more than a simple 2D position. How and what do I mean by
that? Read on.
Understanding tracking points
In the preceding section you only dealt with movement in the horizontal and vertical po-
sition axes. There was no rotation and no scale. That means that every pixel in the image
was moving in the same way as its neighbor. This situation doesn't happen very often.
Usually elements on-screen move more freely and tend to at least rotate (meaning around
the screen's axis) and move towards or away from the camera—thus scaling. So aside
fromposition,thereisalsorotationandscale.Allthesearestrictly2Dmovements(move-
ments you can find in Nuke Transform node, for example) because the element is always
facing the camera. There are movements that include changing the angle an element has
to the camera. I call this perspective movement .
To track rotational value, scaling, or perspective movement, you need more than one
tracking point. Using just onetracking point, asyoudidinthe preceding section, can only
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