Merge Expression

[davef]

hello,

i try to understand how the node Merge Expression works.
does anyone knows ?
i thougth the expression are calculated with the A input channels,
and the result is copied to the B input.
but it does'nt work as simply...

thanks

auD.

[davef]

i had the solution,
Ar, Ag, Aa ... means the red, green, or alpha channel of input A,
Bg, Br, Bb... is the green, red, or blue channel of the input B

actually quite simple....

[user_deleted]

yep, that's all there is to it, plus you can reference x and y positions which is very handy.
here is a simple example of a horizontal wipe using the MergeExpression node:

MergeExpression {
inputs 2
expr0 x>split?Ar:Br
expr1 x>split?Ag:Bg
expr2 x>split?Ab:Bb
channel3 alpha
expr3 x>split?Aa:Ba
name MergeExpression1
label wipe
selected true
xpos -320
ypos -40
addUserKnob {20 User}
addUserKnob {7 split R 0 480}
split 170
}