SampleImage to duplicated layers :0

[Dan Ebberts]

Is your target layer comp-sized and always positioned at the center of the comp? If not, you need to convert your sampling layer’s position into the layer space of the target. It would look like this (not tested):

s =target.sampleImage(target.fromWorld(toWorld(anchorPoint)),area)

Dan

[Micheel Leavitt]

It didn’t work ): I tried changing it to look like this:

target = effect(“Spectrum Layer”)(“Layer”);
area = [width/2,height/2];
x = thisLayer.fromWorld(toWorld(anchorPoint));
s =s =target.sampleImage([x[0],x[1]],area);
r = rgbToHsl(s);
ease(r[2],0,1,-125,125)

It didn’t work. If the position expression is off, it will work properly. If the position expression is turned back on (tested multiple times)it will take the sample from it’s position before the expression was turned on, and apply it to all duplicates (pieces are 15×15 if this helps, NTSC comp settings) The strangest part of all though…I don’t know why, but if I do this in this order it will work:

Turn off position expression
Turn off slider that has sample expression
Turn on position expression
Duplicate until grid is done
Turn on the sample expression on EVERY layer, one at a time DX

Works perfectly if you do this, and why??? I thought maybe because sampleImage is somehow glitched, but I don’t know anything about it really except it usually works great, until this. If this will help, the position expression is the same as the one posted above, and the new sample expression is:

//I know its redundant, just in case the target is 3D for some reason
target = effect(“Spectrum Layer”)(“Layer”);
area = [width/2,height/2];
x = target.fromWorld(toWorld(anchorPoint));
s =s =target.sampleImage([x[0],x[1]],area);
r = rgbToHsl(s);
ease(r[2],0,1,-125,125)

The steps I took up top work with the original sample expression as well, which really makes this strange to me. If anyone has an idea, any info on this would be great!

[Dan Ebberts]

I don’t know what to tell you. I set up a test comp with a 15×15 layer whose position is controlled by an expression with this sampling expression and it works flawlessly:

target = effect(“Spectrum Layer”)(“Layer”);
s = target.sampleImage(target.fromWorld(toWorld(anchorPoint)),[width,height]);
rgbToHsl(s)[2]

Any duplicates of the layer also work. Hard to say what’s going on in your case without seeing your project.

Dan

[Micheel Leavitt]

It does work, flawlessly, until you apply the position expression I used.

//Original code courtesy of Dan Ebberts of motionscript.com
numRows = thisComp.layer(“Null 1”).effect(“num Rows”)(“Slider”);
numCols = thisComp.layer(“Null 1”).effect(“Num Columns”)(“Slider”);
row = Math.floor((index – 1)/numCols);
col = (index – 1)%numCols;
x = col*width/(width-thisComp.layer(“Null 1”).effect(“xOverlap”)(“Slider”)/100);
y = row*height/(height-thisComp.layer(“Null 1”).effect(“yOverlap”)(“Slider”)/100);
xOffset = numCols-thisComp.layer(“Null 1”).effect(“xStart”)(“Slider”);
yOffset = numRows-thisComp.layer(“Null 1”).effect(“yStart”)(“Slider”);
z = effect(“Final Range Value”)(“Slider”);
poz = [x,y,0] + [xOffset,yOffset,z];

its just your grid expression with some sliders, and when I duplicate it, they all follow the original layer’s sample, not a new sample for the offset. It works if you wiggle it though.