public static ArmatureMask createMask(Armature armature, String fromJoint) {
        ArmatureMask mask = new ArmatureMask();
        mask.addFromJoint(armature, fromJoint);
        return mask;
    }
Create an ArmatureMask that selects the named Joint and all its
descendants.

@param armature the Armature containing the joints (not null)
@param fromJoint the name of the ancestor joint
@return a new mask

@throws IllegalArgumentException if it can not find the joint
         with the specified name on the provided armature
jme3-core/src/main/java/com/jme3/anim/ArmatureMask.java