— David Wagner 2009/09/26 11:12

Inspired by today's Astronomy Picture of the Day, I put a starry background on Mike Kost's realskies.inc.

The original high-resolution image is available from by request, but the European Southern Observatory (ESO) makes a TIFF of reasonable size available. It appears to be a spherical map of the night sky perfectly suited to use with POV-Ray's sky_sphere.

The image is aligned with galactic center, so some rotation is necessary to align it with a scene. Here, y is up. The GigaGalaxy Zoom website has a version of this image overlaid with the constellations, so I just used it temporarily until Polaris was straight overhead.

sky_sphere {
   pigment {
      image_map{
         png "stage/phot-32a-09-fullres.png" // the file to read (iff/tga/gif/png/jpeg/tiff/sys)
         map_type 1      // 0=planar, 1=spherical, 2=cylindrical, 5=torus
         interpolate 0   // 0=none, 1=linear, 2=bilinear, 4=normalized distance
         once            // for no repetitive tiling
         }
      rotate <118.5,0,152.8>
      scale <-1,1,1>
      }
#if(true)
   pigment {
      average
      pigment_map {
         [1-clock  p_realsky_07 ]
         [  clock  p_realsky_01 ]
         }
      scale 1/2
      }
#end
}