Apple Shake 4 - Manual (Page 756)

756 Chapter 25 Image Tracking, Stabilization, and SmoothCam
3 Adjust the translationSmooth, rotationSmooth, and zoomSmooth sliders to increase or
decrease the amount of smoothing that is attempted. At 0, no smoothing is attempted
in that dimension. At higher values, SmoothCam attempts to smooth a wider range of
variations in the movement of the image from one frame to the next.
• translationSmooth: Smooths the X and Y motion of the shot.
• rotationSmooth: Smooths rotation in the shot.
• zoomSmooth: Smooths a zoom within the shot.
Important: It’s faster, and will yield more accurate results, if you set the smoothing
parameters of dimensions in which you know the camera is not moving to 0. For
example, if you know for a fact that the camera is neither rotating nor zooming, set
rotationSmooth and zoomSmooth to 0. In particular, if the camera is not zooming,
increasing the zoomSmooth value may actually cause unwanted transformations in
the image.
To lock and match shots using the SmoothCam node:
1 Once the analysis has concluded, set steadyMode to lock.
2 Open the lockDown subtree.
3 The setting of the inverseTransform parameter depends on what you’re trying to do:
• If you want to lock the analyzed shot itself, leave inverseTransform set to lock.
• If you want to apply the motion from this shot to another image, attach this node to
the other image, then set inverseTransform to match.
4 Turn on the locking parameters for the dimensions of motion you want to affect.
• translateLock: Locks the subject in the X and Y dimensions.
• rotateLock: Locks the rotation of the subject.
• zoomLock: Removes zoom from the shot, maintaining the relative size of the subject.
• perspectiveLock: Locks the perspective of the subject, performing the equivalent of a
four-corner warp to maintain the size and shape of the subject.
Troubleshooting SmoothCam Effects
If the output is unsatisfactory, there are several things you can try to improve the result.
Change the Smoothing Parameters
If you’re trying to smooth the motion in a shot, you should first try changing the
smoothing parameters. This can be accomplished without having to reanalyze the clip.
Reanalyze the Media at a Higher Quality
Next, try changing the analysisQuality to high, and reanalyze the media.