This Celestia Add-on requires Celestia v1.3.1prerelease9 or later.
Unzipped into your Celestia
\extras folder, this file creates a
\Grids, which contains the two
ssc files and
png textures necessary to add latitude/longitude grids
to bodies in Celestia's Solar System.
The grid textures appear as two new options in the Alternate Surfaces menu (activated by right-clicking on a planet or moon). When grid textures are available, you will see "Grid Overlay" and "Blank Grid" appearing as options. "Grid Overlay" places a latitude/longitude grid over the default Celestia texture. "Blank Grid" replaces the Celestia texture with a white surface marked out in latitude/longitude lines.
The grids conform to the IAU standard - north pole to the north of the plane of the ecliptic, longitude increasing to the west for direct rotators and to the east for retrograde rotators. Earth and the Moon have their own grids, with both west and east longitude marked. The grids are colour-coded: blue for direct rotators, green for retrograde rotators, orange for the Earth/ Moon grid. They are ruled at 15-degree intervals, and labelled at 30-degree intervals. Grids are available for the giant planets: in the case of Saturn, Uranus and Neptune, they correspond to the IAU-defined prime meridian for System III rotation (the rotation period of the planetary core); for Jupiter, Celestia uses System II rotation to reproduce the position of the Great Red Spot accurately, so the generated grid does not correspond to the IAU-defined rotation.
overlays don't work with 3ds objects at present, but the attached zip
contains textures and
ssc's to lay grids on to the spherical solar system
bodies as Alternate Surfaces. I hope overlays will be extended to
3ds soon, in which case it'll be easy enough to update the
Grant Hutchison, August 2003
Grid Overlay on several planets
This Web page is maintained by Selden Ball
at Wilson Lab.
Please send any comments or corrections to firstname.lastname@example.org