Tip of the Week - HDRi Skies

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Permalink Reply by Render Plus on August 9, 2010 at 1:34pm

An HDri Sky is a full spherical image - 360 degrees pf sky, 180 degrees above the horizon and 180 degrees below the horizon. If you are making a 1,000 pixel rendering with a 60 degree field of view, then you will only see 1/6th of the full image (in width) and 1/2 or less of the image in height, so a 1,000 x 1,000 pixel rendering needs a Sky with at least 1/2 of 6,000 x 6,000 resolution.

I say 1/2 because you can usually enlarge the background image by about 2 : 1 without much loss of quality. So 3,000 x 3,000 would work for the HDRi image, but 6,000 x 6,000 would be better. And for higher resolution renderings, or smaller FOVs you would need even larger images.

Samples of HDRi skies.
Notice how each image covers a full 360 degree Spectrum.
(Images courtesy Evermotion)

Permalink Reply by Michele on August 9, 2010 at 1:50pm

thanks...read that info before in an earlier discussion...but I still cannot use the HDR images when I select from the given library

can you tell me for that particular rendered image what HDRi sky was used and if not was the HDR image altered from the presets in the IRender nXt ...http://www.renderplus.com/wk/Tip_of_the_Week_-_HDRi_Skies_w.htm

I am just trying to simplify the rendering process by selecting from the given presets and still get the desired result of having a background that is reflected and visible - to scale

help?