DESCRIPTION 

Quelea is a plugin for agent-based design which allows you to assign forces and behaviours to systems of agents to create interactions. 

PROCEDURE 

1. Define the particle properties, you can set the lifespan of the particles and the history length to get the moving track of the particles
2. Define a point emission source, you can define the base point, number of particles allowed to exist and the emission rate
3.  Setup the minimum and maximum initial vector of the particle which a random vector will assigned to each particle when emitted
4. Combine the particle settings and emitters to the system component, it requires a timer component to run
5.  Use the engine component to run the system, it requires a timer component to run and a button to reset the simulation
6. Force components are applied after the system, here we applied a downward gravitation force to the particles emitted
7.  Using the deconstruct particle component to extract parameters including the points, vector, acceleration and life span of each particle
8.  From the particle history, we can create a interpolated curve