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# Slow value response, parent to child expression for position

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 Slow value response, parent to child expression for position on Apr 3, 2016 at 6:52:19 pm

Hi Creative Cow. For the life of me I cannot figure this one out.
I am in no way an expression person so that might be why this is not working out so well. I appreciate any help and thank you for taking your time to do so.

I have a null that is moving in X value. It slowly slides across the comp. Next I have some 50 layers parented to the null.

What I'd like to happen is to enter an expression that would allow each layer to react less to the nulls position.

So say layer 1 moves at the nulls exact value.
Layer 2 moves 5% less in value
Layer 3 moves 10% less
Layer 4 20% less
Layer 5 30%

Etc etc

Let me know if you need me to explain this differently. I have looked all over and seem to get stuck on delays, which this is not. Thanks!

 Re: Slow value response, parent to child expression for positionon Apr 4, 2016 at 8:42:37 pm

If "layer 1" is your master layer, the other layers' position can be derived with this expression:

```mult = .5; value+(thisComp.layer("layer 1").transform.position-thisComp.layer("layer 1").transform.position.valueAtTime(0))*mult```

where you can change the "mult" value for how much the master layer's motion affects the current layer.

 Re: Slow value response, parent to child expression for positionon Apr 4, 2016 at 9:10:01 pm

Thank you

 Re: Slow value response, parent to child expression for positionon Apr 4, 2016 at 11:31:19 pm

Question regarding negatives. Can it also go on the other side of speed regarding a minus? Can this also be used in a way to slow down?

 Re: Slow value response, parent to child expression for positionon Apr 5, 2016 at 7:26:56 am

mult = 1 means the same speed as the master layer.

mult = .5 means half the speed

mult = 2 means double the speed

negative numbers would move the layer in the opposite direction

 Re: Slow value response, parent to child expression for positionon Apr 7, 2016 at 5:59:08 am

Got it. Thank you..

pasting the expression outside the iframe.

mult = .5;
value+(thisComp.layer("layer 1").transform.position-thisComp.layer("layer 1").transform.position.valueAtTime(0))*mult