Hi, I don't know if this in the right area of of the forum for after effects, but this is also getting posted into other ones.
I want to take multiple PSD files into after effects and then use a slider control to go through them all? for example at the start of the slider it is one image and then each whole number is a different image? (I know how to make the number rounded up so that's not a problem it's just the images part I'm struggling with.
Add a Null to your comp, add a slider to it and add the expression(you said you knew this, but just posting for those that don't): Math.floor(effect("Slider Control")("Slider"))
Open up one the opacity of one of your pictures and add this expression: mySlider = thisComp.layer("Control").effect("Slider Control")("Slider");
if (mySlider == thisLayer.index-1)(100) else (0)
Just using and If else statement that says, if the slider is Equal to and only equal to the index number of this layer(the -1 is because the layer 1 is the controller), make the opacity 100, else the it's 0
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.