Gravity Engine 2

Gravity Engine 2#

Version 9.1 (March 5, 2026)

Gravity Engine 2 is a Unity asset that provides gravitation simulation and orbital mechanics.

Gravity Engine 2 provides a complete toolkit for your space game physics.

  • create and configure orbits with editor and in-scene views

  • support for manual maneuvers, Hohmann and Lambert transfers

  • propagators for KEPLER, SGP4, ephemeris and PKEPLER motion

  • ability to use multiple evolution engines (no singletons!) in a scene

  • optional use of the Unity job system to offload physics calculations

  • clear separation between gravitational computation and the display of objects, optional multiple displays

  • simple, focused API

  • clear separation of world, physics and display scales

  • support for patched conic evolution

  • ability to build ALL of the solar system (planets, moons and small objects) in a sensible hierarchical model

  • rocket launch with ascent steering (pitch table, gravity turn, PEG)

  • circular three body evolution (cis-lunar etc.) with ability to import halo orbits from JPL

Promo video

There are “quick tour” videos for the sample folders:

Doxygen: API

What’s New in 9.1#

Add an new Evolve mode to GSController to allow job evolution to occur in parallel with Unity physics and renderering. The IJOB_FRAME mode is described in evolve mode.

GSTransferShip now supports a LAMBERT_RDVS_WITH_DELAY mode. This aligns with the Space Shuttle rendezvous computer.

Additional bug fixes are described in the README.

Contents