• Adobe After Effects Expressions

  Switch between a number of layers with slider control

  Posted by Moog Gravett on April 5, 2016 at 2:08 pm

  Hi folks,

  hope someone can help me here.

  I want to partially automate some layer switching but can only find how to do it between two layers thus far.

  I want to have, lets say 5 (but ideally scaleable) layers that I can switch on and off with a 1-5 value on a slider control. Or some other animatable solution of course.

  Any ideas?

  Cheers,

  Moog

  Moog Gravett replied 10 years, 3 months ago 3 Members · 4 Replies
• 4 Replies

• 

  Jakob Wagner

  April 5, 2016 at 2:36 pm

  Hi

  1. Create the five layers. 😉

  2. Create a null and rename it to “control”.

  3. Create a expression control slider on the null.

  4. Rename the slider to “Turnus”.

  5. Insert this code in the Opacity property in all the five layers:

  
var totalLayers = 5;
var layerIndex = 0;
var visible = thisComp.layer("control").effect("Turnus")("Slider")>100/totalLayers*layerIndex;
opacity = visible?100:0;


  6. Layer index on the first layer is 0. Next layer is 1, etc..

  Drag/animate the slider from 0 to 100.

  Hope it helps.

  – Jakob Wagner
• 

  Moog Gravett

  April 5, 2016 at 3:12 pm

  Hi Jakob,

  Thanks very much for your quick reply.
  I gave it a try but as I have it at the moment, the layers aren’t switching, rather it stays on one layer (the one highlighted in the screen grab). Would you mind taking a look to see what I’m doing wrong?

  Cheers,

  
• 

  Miguel De mendoza

  April 5, 2016 at 4:11 pm

  Maybe this ocurs because the slider have coma values(1.3, 2.7)and when interpolating cant find a 1.3 layer. So you can try to floor the slider value, to make this code work you only have to add to your layers name an index sufix “_1”, “_2”, etc…:

  sliderValue = //Your link to the slider
nameSplit = name.split("_"); //
shapeNum = nameSplit[nameSplit.length - 1];

  if (shapeNum == Math.floor(sliderValue)) {
value = 100;
} else {
value = 0;
}
• 

  Moog Gravett

  April 5, 2016 at 4:34 pm

  Brilliant!

  Thanks Miguel, that did the job beautifully.

  All the best and thanks to you both for taking the time to help.

  Moog

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