getObjectByProperty method
name -- the property name to search for.
value -- value of the given property.
Searches through an object and its children, starting with the object itself, and returns the first with a property that matches the value given.
Implementation
Object3D? getObjectByProperty(String name, String value) {
  if (getProperty(name) == value) return this;
  for (int i = 0, l = children.length; i < l; i++) {
    final child = children[i];
    final object = child.getObjectByProperty(name, value);
    if (object != null) {
      return object;
    }
  }
  return null;
}