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Saturday, January 14, 2006

Terranova Updated

Since 1995, Terranova has been serving up a new terraformed planet every day to visitors of this site. One of the curious things about image synthesis is that you may consider the images “pretty good”, but after you correct some inaccuracy in the rendering algorithms, the images you generated before now look awful, while the new ones are now deemed “pretty good”. Terranova was originally based upon the ppmforge program I contributed to the Netpbm image processing toolkit. This, in turn, was derived from the “fractal forgery” module I wrote for Autodesk's Chaos: The Software title. When I later made a Terranova screen saver for Windows, I improved the image rendering substantially compared to that of the original ppmforge: stars were drawn as a Gaussian point spread function depending upon the intensity with the correct colour for their spectral type, star clusters could create Gaussian enhancement of mean star density, and the range of each randomised parameter affecting the image could be specified independently.

While the original ppmforge-generated images once looked “pretty good”, they were distinctly tacky next to those generated by the screen saver, so the next obvious step was to integrate the screen saver's image synthesis into the Web page edition of Terranova. At long last, that project is complete and ready for your inspection. Source code for the updated image synthesis program may be downloaded from a link on the Details page; it is now a stand-alone program which need not be integrated into a Netpbm build (although you'll still need assorted Netpbm utilities to post-process the images it generates).

Since most users browse the Web with higher resolution displays than they did a decade ago, the default image sizes have been increased, although 640×480 images remain available. GIF images have been replaced by PNG, and JPEG is used exclusively for the main high-resolution planet images. All documents are XHTML 1.0 and CSS 2.1 compliant and validated against those standards.

Posted at January 14, 2006 22:03