Tektronix Grass Valley 3000 - Manual (Page 204)

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Section 4— Switcher Operations
Using Path Types To Change An Effect
You can change the appearance of a effect, or parts of an effect by
changing the path type. Path type selection is the way you can
control parameter changes between keyframes. The path type, set
in the Keyframe Path Menu, determines the type of interpolation
that occurs between keyframes of an effect. Each functional group
of each keyframe can have its own path type.
The available path types are Hold, Linear, S-Linear, and Curve.
When LINEAR is selected with the PATH TYPE soft button in the
Keyframe Menu, linear interpolation is applied to each parameter
that changes between one keyframe and the next. This provides
constant motion with no acceleration or deceleration.
The S-LINEAR path type involves accelerating and decelerating
the parameters. The change to each parameter begins from a
complete stop at the starting keyframe, slowly leaves that
keyframe, moves faster through the midrange of the keyframe
duration, then decelerates as it approaches the destination
keyframe, and comes to a complete stop at the keyframe. (The “S”
describes the shape of the curve when graphed against time.)
HOLD stops a crosspoint from changing when an effect is recalled
or a keyframe with new source information is encountered. All
parameters hold at their starting values throughout the keyframe
duration.
HOLD stops the interpolation process between
keyframes, causing a “pop” between changed positions.