Low-connectivity and full-coverage three dimensional Wireless Sensor Networks (WSNs) have many real-world applications. By low connectivity, we mean there are at least k disjoint paths between any two sensor nodes in a WSN, where k ≤ 4. In this paper, we design a set of patterns to achieve 1-, 2-, 3- and 4-connectivity and full-coverage, and prove their optimality under any value of the ratio of communication range r c over sensing range r s, among regular lattice deployment patterns. We further investigate the evolutions among all the proposed lowconnectivity patterns. Finally, we study the proposed patterns under several practical settings.