Celestia Development Status

Transcription

1 Celestia Development Status Chris Laurel 3 rd ESA Workshop on Astrodynamics Tools and Techniques 2-5 October 2006 ESTEC, Noordwijk, The Netherlands

2 Contents Introducing Celestia Development history Feature overview Extensibility Applications Celestia preview Future development goals Resources

3 Introducing Celestia Celestia is an interactive space visualization tool Pick a time and a position, Celestia will show you the view Supports a large range of scales, displaying everything from spacecraft to galaxies Celestia does not model gravity, but it can import trajectory data generated by other software Completely open source application Licensed under GPL 2.0 Project hosted on SourceForge Versions available for Windows, Mac OS X, and Linux Written in C++, using OpenGL for cross-platform 3D

4 Development Timeline Almost six years old first version released February 2001 Current stable version is 1.4.1, created February 2006 Maintained by a core team of six active developers Many more people involved in creating add-ons and scripts Version is coming soon is the most significant update of Celestia so far Should be released early November on all supported platforms Prerelease package is available for testing now

5 Celestia Data Files Star catalogs Galaxy catalogs Substellar objects: planets, natural satellites, small bodies, spacecraft Image maps for planets (simple cylindrical projection) 3D models for small bodies and spacecraft Ephemerides VSOP87 theory used to compute planet positions Osculating elements Unevenly spaced Hermite interpolated position samples

6 Celestia Data Files Standard package HIPPARCOS star catalog, supplemented by RECONS Steinecke's revised NGC/IC catalog (10160 galaxies) Catalog of all confirmed extrasolar planets (as of September 06) All Solar System planets, natural satellites, some small bodies Galileo and Cassini missions Sample ASCII catalog entry: Body 433 Eros Sol { Class asteroid Mesh eros-halfdegree.cmod SampledOrbit eros-orbit.xyz Radius 16.3 # max. semi-axis RotationPeriod 5.20 Albedo 0.16 }

7 Notable Features Multiple simultaneous views Eclipse and ring shadows Orbit paths and object labels Image and movie capture Celestia URLs: link from a web page to a position/time in Celestia

8 Extending Celestia: Add-on packages Simple to create, no programming required Example: Venus Express Add-on contains 3D model of space craft with texture maps, trajectory data, and a single SSC catalog file Venus Express model by Joseph Firestine

9 Extending Celestia: Scripting Scripts are written in Lua, a language designed for application extension ( Many Celestia objects have script interfaces Current scripts are primarily educational Example script: Compares the rotation of all the planets of the Solar System. Script by Harald Schmidt

10 Extending Celestia: Core C++ source modification Example: Real-Time Celestia Visualization of Space Shuttle external tank separation using position and orientation data read across the network Application and screenshots by Scott Nemeth, Johnson Space Center

11 Applications for Celestia Visualization Spacecraft mission visualization Education Museum kiosks and shows Classroom use full set of Celestia-based lesson plans available, written by science teacher Frank Gregorio Scene Generation Generate views of star fields to test star pattern matching algorithms for determining spacecraft attitude (Tim Curry, Miltec Corporation) Production of stills for illustration, animations for broadcast media

12 1.5.0 Features: Improved visuals More realistic photometric functions for planets Atmospheric scattering model Better mesh rendering

13 1.5.0 Features: SPICE Toolkit integration SPICE SPK files can now be used directly by Celestia for computing spacecraft and planet positions. To Celestia, an SPK file is just another ephemeris type that can be specified in a standard add-on. Can use C-Kernel files for spacecraft attitude

14 1.5.0 Features: Continued Internationalization Windows version now has multilanguage support (Linux and Mac OS X versions already had it) Many new translations: Dutch, Russian, Japanese,... Scripting improvements Event handlers: scripts may override handling of mouse and keyboard events Scriptable object trajectories, for trajectory types not natively supported by Celestia More drawing capabilities for scripts Less need to modify the C++ code in order to customize Celestia.

15 Future work High dynamic range rendering: compute physically correct illumination, write to a floating point frame buffer. General shadows currently, shadows are only cast by ellipsoidal bodies and planetary ring systems. Make add-on packages easier to install and manage Use elevation data for planets More flexible trajectory visualization user selected reference object and time span Properly account for light time delay High Definition Celestia: CD-ROM-sized Celestia distribution with high resolution media

16 Resources Main Celestia page: SourceForge project: Discussion forum: Add-on repository: Scripting guide:

17 Demonstration