Create Eye Rig.jsx

/**
 * @name Create Eye Rig
 * @version 1.2
 * @author Kyle Martinez <www.kyle-martinez.com>
 *
 * @description Used specifically for a current project. Creates an eye rig for a selected eye
 * layer. Probably pretty usless outside of this specific use case but has some nice code to
 * steal for future scripts.
 *
 * @license This script is provided "as is," without warranty of any kind, expressed or implied. In
 * no event shall the author be held liable for any damages arising in any way from the use of this
 * script.
 *
 * In other words, I'm just trying to help make life as an animator easier
 * "A rising tide lifts all boats." - John F. Kennedy, 1963
 */

(function createEyeRig() {
    var prefix = prompt("Which side?", "Left");
    if (prefix !== null && prefix !== "") {
        app.beginUndoGroup("Create Eye Rig");
        var comp = app.project.activeItem;
        comp.time = 0;
        var eyeLayer = comp.selectedLayers[0];
        eyeLayer.name = prefix + " Eye";
        var eyelidLayer = eyeLayer.duplicate();
        eyeLayer.selected = false;
        eyelidLayer.selected = true;
        eyelidLayer.label = 16;
        eyelidLayer.name = prefix + " Eyelid";
        var effects = eyelidLayer.property("ADBE Effect Parade");
        var blinkEffect = effects.addProperty("ADBE Slider Control");
        blinkEffect.name = "Blink";
        var expression = [
            "valueAtTime(linear(effect(\"Blink\")(\"Slider\").value,",
            "0,",
            "100,",
            "key(1).time,",
            "key(numKeys).time));"
        ].join(" ");
        eyelidLayer.transform.position.dimensionsSeparated = false;
        eyelidLayer.transform.position.addKey(0);
        eyelidLayer.transform.position.expression = expression;
        eyelidLayer.transform.position.expressionEnabled = false;
        eyelidLayer.transform.position.addKey(1);
        eyelidLayer.transform.scale.addKey(0);
        eyelidLayer.transform.scale.expression = expression;
        eyelidLayer.transform.scale.expressionEnabled = false;
        eyelidLayer.transform.scale.addKey(1);
        eyelidLayer.transform.scale.setValueAtKey(1, [150, 0]);
        eyelidLayer.transform.scale.setValueAtKey(2, [150, 100]);
        eyeLayer.setTrackMatte(eyelidLayer, TrackMatteType.ALPHA_INVERTED);
        blinkEffect.property(1).addToMotionGraphicsTemplateAs(comp, prefix + " Blink");
        var containingComp = comp.usedIn[0];
        var containingCompLayers = containingComp.layers;
        var numContainingCompLayers = containingCompLayers.length;
        for (var l = 1; l <= numContainingCompLayers; l++) {
            var layer = containingCompLayers[l];
            if (layer.source === comp) {
                var blinkProperty = layer.essentialProperty(prefix + " Blink");
                var inTemporalEase = new KeyframeEase(0, 88);
                var outTemporalEase = new KeyframeEase(0, 66);
                blinkProperty.setValueAtTime(comp.frameDuration * 0, 0);
                blinkProperty.setTemporalEaseAtKey(1, [inTemporalEase], [outTemporalEase]);
                blinkProperty.setValueAtTime(comp.frameDuration * 8, 100);
                blinkProperty.setTemporalEaseAtKey(2, [inTemporalEase], [outTemporalEase]);
                blinkProperty.setValueAtTime(comp.frameDuration * 16, 0);
                blinkProperty.setTemporalEaseAtKey(3, [inTemporalEase], [outTemporalEase]);
                blinkProperty.expression = "posterizeTime(12); value;";
            }
        }
        app.endUndoGroup();
    }

})();