Qt Quick 3D - Stencil Outline Extension Example

 // Copyright (C) 2022 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

 import QtQuick
 import QtQuick.Controls
 import QtQuick.Layouts

 Rectangle {
     id: root
     property string title: ""
     property bool isExpanded: true
     default property alias content: container.children
     color: "transparent"
     border.width: 2
     border.color: palette.alternateBase

     Layout.fillWidth: true
     implicitHeight: outsideLayout.implicitHeight

     ColumnLayout {
         id: outsideLayout
         width: parent.width
         Rectangle {
             id: sectionHeader
             Layout.fillWidth: true
             implicitHeight: 24
             color: palette.alternateBase

             RowLayout {
                 anchors.verticalCenter: parent.verticalCenter
                 Image {
                     fillMode: Image.PreserveAspectFit
                     sourceSize: Qt.size(titleText.implicitHeight, titleText.implicitHeight)
                     source: root.isExpanded ? "images/TreeExpanded.png" : "images/TreeUnexpanded.png"
                 }

                 Text {
                     id: titleText
                     Layout.fillWidth: true
                     text: root.title
                 }
             }

             MouseArea {
                 anchors.fill: parent
                 onClicked: root.isExpanded = !root.isExpanded
             }
         }

         GridLayout {
             id: container
             Layout.margins: root.border.width * 2
             visible: root.isExpanded
             Layout.fillWidth: true
             columns: 2
             uniformCellWidths: true
         }

     }

 }