protected void setBoundRefresh() {
        refreshFlags |= RF_BOUND;

        Spatial p = parent;
        while (p != null) {
            if ((p.refreshFlags & RF_BOUND) != 0) {
                return;
            }

            p.refreshFlags |= RF_BOUND;
            p = p.parent;
        }
    }
Indicate that the bounding of this spatial has changed and that
a refresh is required.
jme3-core/src/main/java/com/jme3/scene/Spatial.java