Select

Function
This powerful function allows you to construct different compositing branches and choose between them based on an arbitrary rule you create. This rule can be an animated curve, a rule based on time, a rule based on a node's parameter, or anything else you might want to do.

Example
This tree has two input images, Asteroid and Earth. We want the Earth to orbit around the asteroid. We animate it with the Move2D, and then plug both into 2 Over commands, switching foreground elements for each. The Select function then picks one of the Over commands, based on time to make it look like the Earth is orbiting around the Asteroid. The branch expression says "if the current frame is greater than 14 and less than 32, then use OverA, otherwise, use OverB". You can also just animate the branch number by hand. This is only us being clever. You can, of course, just animate the branch with a curve...


Select statement:

time>14&&time<32?1:2

Earth,

Asteroid

OverA,

OverB

Select1,
frame 5,
frame 20

 

Parameters
Type
Default
Function
branch
int
1
The expression to pick a branch. If the expression equals 1, then the first branch is used, if it equals 2, the second branch is used, etc.


Synopsis

image Select( 
 int branch,
 image,
 image,
 image,
 image
);


Script

image = Select( branch, image, image, image, image);


Command Line

shake -select branch image image image image