I’ve had many questions in the past year or so about the skies I’ve been using in my scenes. For a long time, I wasn’t at liberty to say much about them. No longer.
I’m happy to report that Marcel Vijfwinkel, the man behind the enormously popular CGTextures.com, and his accomplice Wojtek Starak have now launched CGSkies.com – source of the super high-res HDR sky maps I’ve been using as a tester in many of my scenes for months. Those of you who have been using CGTextures’s wonderful JPG sky maps will be glad to know that these skies are now available in HDR versions via CGSkies – not for free, it goes without saying, but they’re worth every penny. Indeed, these are in many ways higher-quality versions of the LDR maps: expertly re-stitched and cleaned up of all landscape elements at the horizon. It is hard to fathom the amount of work that has gone into preparing these maps for sale. No wonder CGSkies has been in the making for so long.
The beauty about CGSkies’ maps is that their very high resolution (up to 15,000 pixels wide) makes it possible to use them both as light sources and as backplates, eliminating the need for separate LDR backplates (though you will need quite a bit of RAM to use them).
The second thing I love about the maps, and probably the most important, is that, assuming you are using Vray as a renderer, their dynamic range allows you to generate very crisp shadows without the need for extra light sources, such as sunlights or direct lights, at least for the maps that feature a visible sun (you can obtain a broad range of hard to soft shadows depending on how overcast the sky is).
In order to generate these shadows without altering the colours of the original map in the environment and reflection slots, Marcel recommends using a more refined version of the HDR workflow I highlighted in this post last year. This involves using the gamma control of the VrayHDR texture map to modulate the contrast of the map (in addition to the multiplier for the map’s intensity). For all the details about Marcel’s own version of this workflow, head to the tutorial section.
The site has a number of free samples, which, although considerably lower-res than the originals, will allow you to test if this workflow works for you (though they won’t generate the beautiful reflections and backdrops of the original-sized maps).
The CGSkies gallery features a few renders of mine, including this one, which shows you what kind of lighting and shadows you can expect, using only the maps.