2017

Table Of Contents
Slip Functions
Use the following functions to slip the starting frame of a clip backwards or forwards using the slip channel.
In effect, the displayed frame in a layer's clip will be the animation's current frame number plus the slip
value. For example, a slip value of -15 holds the clip at the first frame and repeats it 15 times before the clip
begins. In this way, you can create a freeze frame effect with one layer while animating another layer. A slip
value of 10 begins the clip at frame 11. See
Modifying Surfaces (page 500).
NOTE Slip functions are actually implemented as user-defined functions in the functions file. See Defining Your
Own Functions
(page 1269).
pingpong
Returns a slip value that makes a clip continuously cycle forwards and backwards. The result should usually
be assigned to the slip channel of a layer.
pingpong(length)Syntax:
Arguments:
length is the number of frames to display before starting to play backwards. This is
usually the length of the original clip.
Examples:
pingpong(10) returns a slip value that makes a clip continuously play in a forward and
backward cycle from frame 1 to frame 10.
pingpong(30) yields the following curve:
repeat
Returns a slip value that makes a clip continuously repeat forwards. The result should usually be assigned
to the slip channel of a layer.
repeat(length)Syntax:
Arguments:
length is the number of frames to display before repeating from the beginning. This is
usually the length of the original clip.
Examples:
repeat(10) returns a slip value that makes a clip repeat forwards from frame 1 to frame
10.
repeat(30) yields the following curve:
Advanced Animation: About Expressions | 1253