Apple Shake 4 - Manual (Page 741)

Chapter 25 Image Tracking, Stabilization, and SmoothCam 741
Parameters
This node displays the following controls in the Parameters tab:
applyTransform
The foreground element is only transformed if applyTransform is active.
trackType
You can do one-point, two-point, or four-point matchmoves. Different options appear
with the different types.
• 1 pt: Pans the foreground element to match the tracking point. You can optionally
turn off the X or Y movement.
• 2 pt: Pops up two additional parameters, with the option of matching scaling and
rotation of the background element (with the matchScale and matchRotate
parameters).
• 4 pt: Performs corner-pin matchmoving on the foreground element. The pan, scale,
and angle parameters disappear. Toggle to FG mode in the Viewer to adjust the 4
points that are pinned to the background. These points appear as sourceNX/YPosition.
applyX
Turning off the applyX parameter prevents the foreground element from following the
horizontal movement of the tracked subject.
applyY
Turning off the applyY parameter prevents the foreground element from following the
vertical movement of the tracked subject.
transform parameters
This parameter contains the following subparameters:
• xFilter, yFilter: The transformation filter used. Different filters can be used for
horizontal and vertical transformations. For more information on the different kinds
of filters that are available and how they work, see “
Filters Within Transform Nodes ”
on page 862.
• motionBlur: Enables the motion blur for the foreground element. A value of 0 is no
blur; 1 is the high setting. A mid-value is a trade-off between speed and quality. This
value is multiplied by the motionBlur parameter in the Globals tab.
• shutterTiming: A subparameter of motionBlur. Shutter length. 0 is no blur, whereas 1
represents a whole frame of blur. Note that standard camera blur is 180 degrees, or a
value of .5. This value is multiplied by the shutterTiming parameter in the Globals tab.
• shutterOffset: A subparameter of motionBlur. The offset from the current frame that
the blur is calculated. Default is 0; previous frames are less than 0. The Global
parameter shutterOffset is added to this.
• aspectRatio: This parameter inherits the current value of the defaultAspect global
parameter. If you’re working on a nonsquare pixel or anamorphic image, it is
important that this value is set correctly to avoid unwanted distortion in the image.