footage switch with expression is there?

[Kevin Camp]

i don’t think you can do that with an expression quite like that…

you could put all the footage layers into one comp, then add an expression to the opacity property of each footage layer that would set the opacity (either 0 or 100) based on the value of the slider. that slider could be in a separate comp than the footage comp, if you needed to keep the footage as a single layer — the footage would be in a comp that would be nested in the comp with the slider.

to do something like that, first add the 12 clips to a new comp (i’ll call ‘main’) in the order that you want (1 being topmost, 12 being last). select all those layers and choose layer>pre-compose.

in the main comp add a slider to the nested footage comp. in the footage comp, add an expression to the opacity property of a footage layer that looks something like this:

if (Math.floor(comp(“main”).layer(“footage comp”).effect(“Slider Control”)(“Slider”))==index) 100 else 0;

then, with that opacity property selected choose edit>comp expression only. select the other footage layers and choose edit>paste.

now if you go back to the main comp, you should be able to edit the value of the slider to make the different footage layers visible.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Kristijan Mrsic]

Hi,

Thank you, that’s exactly what I did, without floor function.
And since this comp is going to be duplicated many times I alsu used index function so in the expression I only need to change the name of the slider for it to work. (And do copy expression only).

Kristijan