Simple Opacity Expression ?help?

[Lord Scales]

Try this:

layerOp = thisComp.layer (“Layer 1”).opacity //the other layer

linear (layerOp, 0, 100, 100, 0) //as the opacity goes from 0 to 100, the value goes from 100 to 0

[Robin Hamilton]

That works perfectly. I was waaaaay off on the wrong path. I would never have figured that out.

Thanks a lot.

[Dan Ebberts]

This is a little simpler:

100 – thisComp.layer(“Layer 1”).transform.opacity

Dan

[Robin Hamilton]

Thanks Dan, that works great as well.

[Gary Mayes]

Hi guys

I’m not a natural when it comes to expressions, so hence me asking this – Why oh why does the 100 – at the front of ‘100 – thisComp.layer(“Layer 1”).transform.opacity’ make this happen? Finding this was so helpful, as it meant that I didn’t need to keyframe two layers to replace one element with another.

I just want to understand what’s going on in such a simple expression. Help me learn – please!

Thanks

Gary

Motion graphics designer and filmmaker

[Dan Ebberts]

When Layer 1’s opacity is 100, this layer’s (the layer with the expression) opacity is 100 – 100, which is zero. When Layer 1’s opacity is 50, this layer’s opacity is 100 – 50, which is 50. So the “100 – ” is what establishes the inverse relationship between the opacities of the two layers.

Dan

[Gary Mayes]

Thanks Dan, that makes perfect sense!

Gary

[Mark Likosky]

I’m trying to create a preset or expression to fade out the last 7 frames. Having a hard time figuring out to make it happen.

thought this was a similar thread on how to do that

[Dan Ebberts]

Try this:

fadeDur = framesToTime(7);
ease(time,outPoint-fadeDur,outPoint,value,0)

Dan

[Mark Likosky]

Dan,

That seems to work nicely!

I’m just getting the hang of expressions. How do I save that as a preset?

Thx!

fadeDur = framesToTime(7);
ease(time,outPoint-fadeDur,outPoint,value,0)