基于文本基线创建辅助线

addTextLayerBaselineGuide.js

// from https://community.adobe.com/t5/after-effects-discussions/baselinelocs-make-me-confused/td-p/12385553
function addTextLayerBaselineGuide(layer, comp) {
    guideIndex = [];

    var anchorPoint = layer.anchorPoint.value,
        positionPoint = layer.sourcePointToComp([ anchorPoint[0], anchorPoint[1] ]),
        tlW = layer.sourceRectAtTime(comp.time, !1).width,
        tlH = layer.sourceRectAtTime(comp.time, !1).height,
        tlT = layer.sourceRectAtTime(comp.time, !1).top,
        tlL = layer.sourceRectAtTime(comp.time, !1).left,
        upLeft = layer.sourcePointToComp([ tlL, tlT ]),
        bottomRight = layer.sourcePointToComp([ tlW + tlL, tlH + tlT ]);
    var textLine = layer.text.sourceText.value.baselineLocs.length / 4;
    var baselineLocs = layer.text.sourceText.value.baselineLocs;

    tempIndex = comp.addGuide(1, upLeft[0]);
    guideIndex.push(tempIndex);
    tempIndex = comp.addGuide(1, bottomRight[0]);
    guideIndex.push(tempIndex);
    for (var i = 0; i < textLine; i++) {
        tempIndex = comp.addGuide(0, positionPoint[1] - anchorPoint[1] + baselineLocs.slice(i * 4, (i + 1) * 4)[1]);
        guideIndex.push(tempIndex);
    }
}
var cc = app.project.activeItem;
var sel = cc.selectedLayers[0];

addTextLayerBaselineGuide(sel, cc);