@Override
    public void getRandomPointAndNormal(Vector3f store, Vector3f normal) {
        super.getRandomPointAndNormal(store, normal);
        // now move the point from the mesh's face toward the center of the mesh
        // the center is in (0, 0, 0) in the local coordinates
        store.multLocal(FastMath.nextRandomFloat());
    }
Randomly selects a point inside the convex hull
of a randomly selected mesh.
The {@code normal} argument is not used.

@param store
       storage for the coordinates of the selected point
@param normal
       not used in this class
jme3-core/src/main/java/com/jme3/effect/shapes/EmitterMeshConvexHullShape.java