How to access sub-object of an .obj file in Qt3D?

Ansjj

I'm working on a 3D viewer whose job is to view a human face model and change its attribute e.g. nose length. I'm using Qt3D QML to import and view 3D face. But I want a way to interact with its vertices or some sort of way to modify this mesh on sub object level. I've done some research on Qt3D qml but could find any appropriate qml element. If its not possible with QML then I want some help that how can I do this in Qt3D C++ API.
Code to import face.obj
@
import QtQuick 2.0
import Qt3D 2.0
import Qt3D.Shapes 2.0

Rectangle{
width: 1100/2
height: 800/2
color:'#a9a9a9'

Viewport {
    width: 1100/2
    height: 800/2


    Item3D {
        scale:-0.1
        position: Qt.vector3d(2,1,-1)
        mesh:  Mesh {
            id: face
            source: "face.obj"
        }

}@