public void setContactResponse(boolean responsive) {
        int flags = rBody.getCollisionFlags();
        if (responsive) {
            flags &= ~CollisionFlags.NO_CONTACT_RESPONSE;
        } else {
            flags |= CollisionFlags.NO_CONTACT_RESPONSE;
        }
        rBody.setCollisionFlags(flags);
    }
Enable/disable this body's contact response.

@param responsive true to respond to contacts, false to ignore them
(default=true)
jme3-jbullet/src/main/java/com/jme3/bullet/objects/PhysicsRigidBody.java