Once the initial cofiguration is chosen, non or overlaping, then the simulation can start by starting the corresponding operations from the "Run" menu. For a non-overlaping system, the final configuration after growing a "killing" central sphere is shown below.
For a non-overlaping system, the final configuration after growing a "pushing" central sphere is shown below.
The blue circle above indicates the radius or farthest distance of reaction, i.e. the distance of the farthest small sphere that was moved due to the growing central sphere. The yellow circle denotes the average radius or distance from all of the distances of the particles whose positions got updated.