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Simple Opacity Expression ?help?
I tried searching for this, but can’t quite figure out what to call it 🙂
Basically I want the opacity of one layer to be linked with the opacity of another layer, but in a negative way. I am using hold keyframes to turn a layer’s opacity from 0% to 100%. I would like another layer to do the opposite… So all I have to do throughout the animation is set hold keyframes for one layer, and the other layer’s opacity will go to 100% when the keyframed layer is set to 0%.
I know this should be a simple expression, but it seems the programming side of my brain doesn’t work too well.
Thanks!
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11 Replies
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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
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That works perfectly. I was waaaaay off on the wrong path. I would never have figured that out.
Thanks a lot.
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This is a little simpler:
100 – thisComp.layer(“Layer 1”).transform.opacity
Dan
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Thanks Dan, that works great as well.
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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
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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
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Thanks Dan, that makes perfect sense!
Gary
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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
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Try this:
fadeDur = framesToTime(7);
ease(time,outPoint-fadeDur,outPoint,value,0)Dan
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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)
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