A constraint can for example, hold a particle in a position no matter what forces are applied. Descendants of this class are required for it to be useful. One of which needs to be connected to the particle system for the processing to take place. Forces Forces will applied to the particles during the step ODE solving process. A force can be universal with a value and a fall off and will be applied to all particles.
Forces can also be specific and applied to only particular particles.
A PointForce, SphericalForce and a SpringForce are supplied. Particle emitters can be used to generate particles. The number generated per second, the particles initial state and the life of the particles generated can be specified. Particles can be generated manually. Descendants of this class are required for specific emitter tasks.