Usage guide for Compositing with Carbon Basic Follow Filter
The Follow filter takes positional information from a key source and alters positional information in the keyed
The Follow filter has three types of channels, Position, Endpoint, and Orientation. These channels derive
their information from a key source's edge data, center of the frame ("hot-spot"), center of rotation, edge slope,
or frame rotation.
The selected key values are used to form an offset to the position of the keyed element. This allows an element
to, for example, follow the edge of another element, or remain at a fixed offset from another element, etc.
This channel is only used for lines to move the second (end) point. An example would be to use the position
channel to move the origin of a line relative to one element, and use the endpoint channel to move the other end
of the line relative to a second element. This would result in a line connecting the two elements wherever they
might move in the composite.
This channel does not change the location of the keyed element, but instead causes the element to be rotated
by the relative angle between the keyed element and the key source element. An example would be a simulation
of the solar system using the orientation channel to keep the Moon facing Earth at all times.
For images the edge data is simply the rectangle used in placing it onto the canvas. For generated shapes it
is the list of points used to create the shape. Movement along edge data is proportional to the total linear length
of all lines, including curvature, to the elapsed time to total time ratio.
Edge following can run backwards by selecting "Retrograde". It can also be advanced in time to start from anywhere
along the edge. Time can also be modified to cause more or less than one full trip around the edge using the
"loop time" value. This sets the time for one complete trip around the edge. The default value results in one trip.