In this paper, we combine two frameworks in the context of an important application. The first framework, called "artificial physics", is described in detail in a companion paper by Spears and Gordon (1999). The purpose of artificial physics is the distributed spatial control of large collections of mobile physical agents. The agents can be composed into geometric patterns (e.g., to act as a sensing grid) by having them sense and respond to local artificial forces that are motivated by natural physics laws. The purpose of the second framework is global monitoring of the agent formations developed with artificial physics. Using only limited global information, the monitor checks that the desired geometric pattern emerges over time as expected. If there is a problem, the global monitor steers the agents to self-repair. Our combined approach of local control through artificial physics, global monitoring, and "steering" for self-repair is implemented and tested on a problem where multiple agents from a hexagonal lattice pattern.