public void setWorldMin(Vector3f worldMin) {
        this.worldMin = worldMin;
    }
Alter the coordinate range. Not allowed after attaching the app state.

@param worldMin the desired minimum coordinate values when using
AXIS_SWEEP broadphase algorithms (not null, alias created,
default=-10k,-10k,-10k)
jme3-jbullet/src/main/java/com/jme3/bullet/BulletAppState.java