The texture size is listed as 32768x16384, but there are actually four maps at 16384x8192 each; many editing applications are limited with such large images. With my software for the full size I could only save a 1.5 G TIFF file (very unwieldy in MAX even with 16 G of RAM. Thus, the archive includes a 3ds Max scene (Max 9.0) with an enormous (size) 4-part spherical mesh object, uv mapped and ready to go (rendering setup is Mental Ray). The most efficient way to do the stars in a space environment is to composite it in later, especially when you're using Final Gather & motion blur. In early experiments, the FG process was increased tenfold when rendering all elements together with the background. As a result of experiments for trying to achieve good star quality with an acceptable dynamic range in a full 360 degree environment, I ended up with these enormous maps. After realizing most users would not necessarily keep them that size, I left them in bitmap format to minimize quality loss upon re-sizing or other manipulations. Also, the download size was not reduced by using other formats.
If desired and you have the capability, you could re-combine them into a single map and use it as a single environment map (spherical mapping, and a u-v tile of -1 and 1 respectively). But be aware that many applications don't support images over 30k pixels in either dimension. If your system(s) has less than about 3G of ram, you'll definitely want to use them as four separate maps. Regardless, I would recommend keeping the four maps & using the max scene provided for rendering background sequences. For more info and details on usage of these maps, see 'starfield.txt.'
It's not necessary to use the provided Max scene. All that is necessary is to create a sphere primitive, map it spherically, and divide it up into four 'quadrants' (see 'sphere_mapping.jpg' and 'quadrants_detached.jpg'). The four meshes can then have the four maps applied. All four maps match up perfectly. Again, for more info see 'starfield.txt.'
All of the images shown were rendered at 1200x1200, and unless otherwise stated the camera's FOV was 45 degrees. This map is large enough to produce high quality renders down to a FOV of about 20, and as large as 1920x1080. For most applications, a FOV of 45 is more than sufficient.
These maps show the sky as seen from the perspective of our solar system. All major constellations, the brightest Messier/NGC objects, and the Milky Way. It's a bit enhanced for artistic purposes, and adjusting the filtering/anti-aliasing gives different results. The settings I found to be best are set up in the Max scene ready to be rendered with Mental Ray.