User Manual

Planar Transform Node [Pxf]
The Planar Transform node
The Planar Transform node applies perspective distortions generated by a Planar Tracker node
onto any input mask or masked image. The Planar Transform node can be used to reduce the
amount of time spent on rotoscoping objects. The workflow here centers around the notion that
the Planar Tracker node can be used to track objects that are only roughly planar. After an
object is tracked, a Planar Transform node can then be used to warp a rotospline, making it
approximately follow the object over time. Fine-level cleanup work on the rotospline then
must be done.
Depending on how well the Planar Tracker followed the object, this can result in substantial time
savings in the amount of tedious rotoscoping. The key to using this technique is recognizing
situations where the Planar Tracker performs well on an object that needs to be rotoscoped.
A rough outline of the workflow involved is:
1 Track: Using a Planar Tracker node, select a pattern that represents the object to be
rotoscoped. Track the shot (see the tracking workflow in the Track section for the
Planar Tracker node).
2 Create a Planar Transform node: Press the Create Planar Transform button on the
Planar Tracker node to do this. The newly created Planar Transform node can be freely
cut and pasted into another composition as desired.
3 Rotoscope the object: Move to any frame that was tracked by the Planar Tracker. When
unsure if a frame was tracked, look in the Spline Editor for a tracking keyframe on the
Planar Transform node. Connect a Polygon node into the Planar Transform node. While
viewing the Planar Transform node, rotoscope the object.
4 Refine: Scrub the timeline to see how well the polygon follows the object. Adjust the
polyline on frames where it is off. It is possible to add new points to further refine
the polygon.
Inputs
The Planar Transform has only two inputs:
–
Image Input: The orange image input accepts a 2D image on which the transform
will be applied.
–
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 Transform to certain areas.
Chapter – 107 Tracker Nodes 2416