Can I resize, with expressions, a picture accordling to the comp size?

[Dan Ebberts]

Do you just need the height to match the comp height? If so, this should work:

s = (thisComp.height/height)*100;
[s,s]

If you need it to match either the comp width or the comp height (depending on which one doesn’t cause clipping)and have to deal with the possibility of the image not having the same pixel aspect ratio as the comp, there’s more work to do.

Dan

[Robert Trione]

Dan,

How would I write an expression for particular that uses the comp size to determine the box Emitter size? I’m trying to make a better particular preset. At the moment I have to manually change the emitter size. Thanks.

[Dan Ebberts]

Couldn’t you just set the Emmiter Size X to thisComp.width and Emitter Size Y to thisComp.height? Or are you after something more complex?

Dan

[Robert Trione]

I feel silly now. No, that sounds perfect. Thank you.

[Djame Goldston]

This thread is old, but thought I’d add my 2 bits for google’s sake… and for mine if I forget how to write the damn expression. lol.

I use this for NTSC output. Comp of unknown size and image of unknown size. Aspect compensation width only (NTSC) and this assumes square pixel images though I would think you could modify to check and compensate… it would be a pain for legacy aspects. You could also pull the “p” and fix the width (“s”1) by “* 90;”.

w = thisLayer.width;
h = thisLayer.height;

compW = thisComp.width;
compH = thisComp.height;

p = thisComp.pixelAspect;

s1 = (compW / w ) * 100;
s2 = (compH / h ) * 100;

if ( s1 > s2 ){ //test size difference
[ s2 , s2 ]
}else{
[ s1 * p , s1 * p ]
}

[Djame Goldston]

Oops, I left off the aspect correction for the height. See below…

w = thisLayer.width;
h = thisLayer.height;

compW = thisComp.width;
compH = thisComp.height;

p = thisComp.pixelAspect;

s1 = (compW / w ) * 100;
s2 = (compH / h ) * 100;

if ( s1 > s2 ){ //test size difference
[ s2 * p , s2 * p ]
}else{
[ s1 * p , s1 * p ]
}