Chapter 1. Introduction

Step is an interactive physical simulator.

Step features:

  • Classical mechanical simulation in two dimensions

  • Particles, springs with dumping, gravitational and coulomb forces

  • Rigid bodies

  • Collision detection (currently only discrete) and handling

  • Soft (deformable) bodies simulated as user-editable particles-springs system, sound waves

  • Molecular dynamics (currently using Lennard-Jones potential): gas and liquid, condensation and evaporation, calculation of macroscopic quantities and their variances

  • Units conversion and expression calculation: you can enter something like "(2 days + 3 hours) * 80 km/h" and it will be accepted as distance value (requires libqalculate)

  • Errors calculation and propagation: you can enter values like "1.3 ± 0.2" for any property and errors for all dependent properties will be calculated using statistical formulas

  • Solver error estimation: errors introduced by the solver is calculated and added to user-entered errors

  • Several different solvers: up to 8th order, explicit and implicit, with or without adaptive timestep (most of the solvers require GSL library)

  • Controller tool to easily control properties during simulation (even with custom keyboard shortcuts)

  • Tools to visualize results: graph, meter, tracer

  • Context information for all objects, integrated wikipedia browser

  • Collection of example experiments, more can be downloaded with KNewStuff2

  • Integrated tutorials