User Manual

Inputs
The Planar Tracker has four inputs:
–
Background: The orange background image input accepts a 2D image with the
planar surface to be tracked.
–
Corner Pin 1: The green corner pin 1 input accepts a 2D image to be pinned on top
of the background. There may be multiple corner pin inputs, named Corner Pin 1,
Corner Pin 2,…etc.
–
Occlusion Mask: The white occlusion mask input is used to mask out regions that
do not need to be tracked. Regions where this mask is white will not be tracked.
For example, a person moving in front of and occluding bits of the pattern may be
confusing the tracker, and a quickly-created rough rotomask around the person can
be used to tell the tracker to ignore the masked-out bits.
–
Effect Mask: The blue input is for a mask shape created by polylines, basic primitive
shapes, paint strokes, or bitmaps from other tools. Connecting a mask to this input
limits the output of the Planar Tracker to certain areas.
Basic Node Setup
A basic Planar Tracker setup consists of just two nodes: a MediaIn connects to the background
input and the Planar Tracker can be used as a separate branch from the rest of the node tree.
Once the tracking is completed, a Planar Transform node should be generated to use the planar
tracking data.
A Planar Tracker can be isolated on its own branch of a node tree
A Typical Planar Tracker Workflow
The following steps outline the workflow with the Planar Tracker:
1 Remove lens distortion: The more lens distortion in the footage, the more the resulting
track will slide and wobble.
2 Connect footage: Connect a Loader or MediaIn node that contains a planar surface to
the orange background input and view the Planar Tracker node in a viewer.
3 Select a reference frame: Move to a frame where the planar surface to be tracked is
not occluded and click the Set button to set this as a reference frame.
4 Choose the pattern: In the viewer, make sure the onscreen controls are visible, and
draw a polygon around the planar surface you want to track. This is called the “pattern.”
In most cases, this will probably be a rectangle, but an arbitrary closed polygon can be
used. The pixels enclosed by this region will serve as the pattern that will be searched
for on other frames. Note that it is important that the pattern is drawn on the reference
frame. Do not confuse the pattern with the region to corner pin (which always has four
corners and is separately specified in Corner Pin mode).
Chapter – 107 Tracker Nodes 2406