This paper presents a potential-function-based formation shape control scheme for swarm simulation. The potential function is designed to avoid collision among agents, approach a destination, and achieve a certain shape formation around the destination. The agents move in a swarm to the formation position, which is generated from a reference point and the neighboring agents. In the framework, a local minimum case created by combining the potential repulsed from neighboring robots and that attracted from a reference point is presented; herein, a robot escapes from a local minimum using a virtual escape point after recognizing the trapped situation. Similarly, in the proposed framework, for a well-equipped formation shape, potential functions are designed to maintain the same relative distance between neighboring robots on a formation line, which also satisfies scalability for the number of agents. The simulation results show that the proposed approach can effectively construct elliptical, diamond, and heart-shaped formations for swarm agents.