a collection of entities, related or unrelated, that comply with a set of logical and physical rules
a collection of independant entities, known as particles, which are animated using a set of rules, with the intention of modelling some effect
a collection of independent objects, often represented by a simple shape or dot
a collection of independent points, which are animated using a set of rules, with the intention of modeling some effect
a collection of many many minute particles that together represent a fuzzy object
a collection of many minute particles that model some object
a collection of small shaded objects that act together as a group with a degree of randomness
a simple object that merely manipulates a group of entities according to a set of rules
a simple physics model that deals only with point-masses and forces
a special type of primitive , because it can not be modeled