Actually worked out the math, so if you had 42 pictures and dropped them into a comp, you could paste this expression all of them except the the top layer---the expression calculates position based on the layer above it, won't work on the top layer(no layer above it). So the top layer will be your control layer. This will work with different size pictures

`startPos = thisComp.layer(index-1).transform.position;`

w= ((thisComp.layer(index-1).width)+(thisLayer.width))/2;

startPos + [w,0]

Here's a quick example project I made:

6258_offsetpositionexpression.aep.zip
Johnny Cuevas, Editor

Thinkck.com

"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.