Increase Comp Resolution in Extendscript while keeping everything centered

[johnt53984649]

When I use the following to increase the resolution of a composition in extendscript:

mycomp.width = width

mycomp.height = height

The compositions resolution changes, but the positions of all items in the comp remain identical. This is the not the same as changing the composition resolution through the dialog box manually, which adjusts the positions accordingly (so the items remain centered).

Here's a video showing my problem. What does my script need to look like so that I don't get the black bars (I want the same effect as changing the resolution manually)?

https://www.youtube.com/watch?v=t12EC4PRt1M&feature=youtu.be

[Tomas Sinkunas]

You need to shift all the layers in the comp by sizeDelta/2, like this:

var composition = app.project.activeItem;
if (!composition || !(composition instanceof CompItem)) {
	return alert('Please select composition first');
}

var widthOld = composition.width;
var widthNew = widthOld * 2;
var widthDelta = widthNew - widthOld;

var heightOld = composition.height;
var heightNew = heightOld * 2;
var heightDelta = heightNew - heightOld;

app.beginUndoGroup('change comp size');
composition.width = widthNew;
composition.height = heightNew;

for (var i = 1, il = composition.numLayers; i <= il; i ++) {
	var layer = composition.layer(i);
	var positionProperty = layer.property('ADBE Transform Group').property('ADBE Position');
	var positionValue = positionProperty.value;

	positionProperty.setValue(positionValue + [widthDelta/2, heightDelta/2]);
}

app.endUndoGroup();

[johnt53984649]

Thank you, but I'm afraid this won't work if any of the layers have their position keyframed. How would you account for that?

[Tomas Sinkunas]

Here's how it could work for keyframed layers

var composition = app.project.activeItem;
if (!composition || !(composition instanceof CompItem)) {
	return alert('Please select composition first');
}

var widthOld = composition.width;
var widthNew = widthOld * 2;
var widthDelta = widthNew - widthOld;

var heightOld = composition.height;
var heightNew = heightOld * 2;
var heightDelta = heightNew - heightOld;

var offset = [widthDelta / 2, heightDelta / 2];

app.beginUndoGroup('change comp size');
composition.width = widthNew;
composition.height = heightNew;

for (var i = 1, il = composition.numLayers; i <= il; i++) {
	var layer = composition.layer(i);
	var positionProperty = layer.property('ADBE Transform Group').property('ADBE Position');

	if (positionProperty.numKeys > 0) {
		for (var j = 1, jl = positionProperty.numKeys; j <= jl; j++) {
			var keyValue = positionProperty.keyValue(j);
			positionProperty.setValueAtKey(j, keyValue + offset);
		}
	} else {
		var positionValue = positionProperty.value;
		positionProperty.setValue(positionValue + offset);
	}
}

app.endUndoGroup();

[johnt53984649]

I didn't realize you could check for keyframes like that. This is perfect. Thank you so much!