Step is an open source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

 two-dimensional physics simulation engine

Physics engine

A physics engine is computer software that provides an approximate simulation of certain physical systems, such as rigid body dynamics , soft body dynamics, and fluid dynamics, of use in the domains of computer graphics, video games and film. Their main uses are in video games , in which case the...

 that is included in the KDE SC

KDE Software Compilation

The KDE Software Compilation is a desktop environment and an associated range of KDE Applications produced by KDE. Prior to version 4.4, released in February 2010, the Software Compilation was known as KDE, which used to stand for K Desktop Environment until November 2009...

 as a part of KDE Education Project

KDE Education Project

The KDE Education Project develops free educational software based on the KDE technologies.- History :The KDE Education project was started in July 2001.- List of software :This software is bundled in the kdeedu package.- Languages :...

. The software include the StepCore, a physical simulation library.

History

The program was developed by Vladimir Kuznetsov and introduced in February 2007. It was released along with KDE 4.1.

Licensing

The program is licensed under the terms of GNU General Public License

GNU General Public License

The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

, making it free software

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

.

Description

Step is based on bodies and forces placed by the user:

• Bodies range from tiny particles to huge polygons, and each body has unique properties that influence the outcome of the simulation
  Computer simulation
  A computer simulation, a computer model, or a computational model is a computer program, or network of computers, that attempts to simulate an abstract model of a particular system...
  
  , such as mass
  Mass
  Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
  
   and velocity
  Velocity
  In physics, velocity is speed in a given direction. Speed describes only how fast an object is moving, whereas velocity gives both the speed and direction of the object's motion. To have a constant velocity, an object must have a constant speed and motion in a constant direction. Constant ...
  
  , and their derivations such as kinetic energy
  Kinetic energy
  The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...
  
  .

• Forces can be either placed directly by the user or produced by adding gravitation
  Gravitation
  Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...
  
  , Coulomb force or other effects.

The program also features springs

Spring (device)

A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication...

 and soft bodies

Soft body dynamics

Soft body dynamics is a field of computer graphics that focuses on visually realistic physical simulations of the motion and properties of deformable objects . The applications are mostly in video games and film. Unlike in simulation of rigid bodies, the shape of soft bodies can change, meaning...

.

Step allows reverting after simulation, so the user can modify the bodies and forces and see how the outcome of the simulation is affected. All the bodies and forces can also be modified in real time.

The software allows users to add graphs and meters and configure them to any property of any body. This allows, for example, graphing speed or acceleration against time.