osgEphemeris::StarField Class Reference

A spherical set of points representing the positions of the stars as seen from a single viewpoint on the surface of the earth. More...

List of all members.

Public Member Functions
	StarField (const std::string &fileName="", double radius=_defaultRadius)
unsigned int	getNumStars ()
void	setSunAltitude (double altitude)
Classes
struct	StarData

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Detailed Description

A spherical set of points representing the positions of the stars as seen from a single viewpoint on the surface of the earth.

StarField contains a set of points set at a constant radius from a center. Each point represents the projection of a star in the sky on to a sphere with radius as specified in the constructor. Each point represents the position of the star and is rendered with a brightness that approximates the corresponding magnitude as specified in a database of stars.

The current database of stars come from The Yale Bright Star Catalogue, from the YBS.edb file of XEphem 3.5.2.

No attempt is made to position stars in reference to each other over long periods of time. The assumption is made that star positions are representative of constellation make up of current times. Thus, the entire set of points is rotated uniformly to position them with approximation to the correct positions in the sky given latitude, longitude, date and time.

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Constructor & Destructor Documentation

osgEphemeris::StarField::StarField (  const std::string &  fileName = "", double  radius = _defaultRadius )

Constructor. Parameters: fileName  - The name of the file containing the catalogue of stars radius  - The radius of the projection sphere

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Member Function Documentation

unsigned int osgEphemeris::StarField::getNumStars (   )

Get the total number of stars in the Star Field

void osgEphemeris::StarField::setSunAltitude (  double  altitude  )

Set the SunAltitude. This is used to determine brightness of the stars according to daylight scatter in the atmosphere. When the sun is below the horizon, stars are visible, when above they are not.

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The documentation for this class was generated from the following file:

• StarField

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