レイヤーの上下左右の端に、ヌルを親として作成するスクリプト

以下のスクリプトは、選択した複数レイヤーの矩形の上下左右の端に、ヌルを親として作成するスクリプトです。

このスクリプトは、アンカーポイントが[0,0]にあるシェイプレイヤーには効果がありますが、アンカーポイントが０でなかったり、通常のレイヤーには効果がありません。

この問題をどなたか解決できませんか。　よろしくお願いします。

    var proj = app.project;

    // Ensure a composition is open
    var comp = proj.activeItem;

    // Ensure layers are selected
    var selectedLayers = comp.selectedLayers;

    // Prompt the user to select the position of the null object
    var positionOptions = ["center", "top", "bottom", "left", "right"];
    var position = prompt("select position (center, top, bottom, left, right):", "right");


    // Start undo group
    app.beginUndoGroup("Create Null at Selected Position");

    // Calculate the bounding box of the selected layers
    var minX = Infinity, maxX = -Infinity;
    var minY = Infinity, maxY = -Infinity;

    for (var i = 0; i < selectedLayers.length; i++) {
        var layer = selectedLayers[i];
        var layerBounds = layer.sourceRectAtTime(comp.time, false);

        var layerMinX = layer.position.value[0] + layerBounds.left;
        var layerMaxX = layerMinX + layerBounds.width;
        var layerMinY = layer.position.value[1] + layerBounds.top;
        var layerMaxY = layerMinY + layerBounds.height;

        minX = Math.min(minX, layerMinX);
        maxX = Math.max(maxX, layerMaxX);
        minY = Math.min(minY, layerMinY);
        maxY = Math.max(maxY, layerMaxY);
    }

    var centerX = (minX + maxX) / 2;
    var centerY = (minY + maxY) / 2;
    var centerZ = 0;

    var nullPosition = [centerX, centerY, centerZ];

    switch (position) {
        case "top":
            nullPosition = [centerX, minY, centerZ];
            break;
        case "bottom":
            nullPosition = [centerX, maxY, centerZ];
            break;
        case "left":
            nullPosition = [minX, centerY, centerZ];
            break;
        case "right":
            nullPosition = [maxX, centerY, centerZ];
            break;
    }

    // Create a null object at the calculated position
    var nullLayer = comp.layers.addNull();
    nullLayer.name = "Positioned Null (" + position + ")";
    nullLayer.position.setValue(nullPosition);

    // Parent the selected layers to the null object
    for (var i = 0; i < selectedLayers.length; i++) {
        var layer = selectedLayers[i];
        layer.parent = nullLayer;
    }

    // End undo group
    app.endUndoGroup();