"motorsep" <nomail@nomail> wrote in message 
news:web.451c72fa9f6ff81ce79570f0@news.povray.org...
> never mind :) I got it. For HDRI MegaPov has special map_type that equals 
> 7
>
>

Make sure your map-type matches your image type as HDRI probes of various 
types are found on the web.  The special map_type 7 is for mapping angular 
maps to a sphere.  Angular maps are circular in shape and look similar to a 
direct picture of a mirror ball, but the two should not be confused, as they 
are quite different.  For an angular map, the distance from the center of 
the image corresponds linearly to the angle of the line of sight, whereas 
with a mirrorball image, the angles get crunched together as the angle 
increases.  With angular maps, less resolution loss occurs at the higher 
angles (depending on how it is assembled however).  Several probes from Paul 
Devbec's site (don't have the link onhand) are angular and can be used with 
the map-type 7.  Mirrorball images can't be used directly, they must be 
converted to either angular or longitude-latitude and mapped appropriately. 
Longitude-latitude is probably the most common type to be found, and the 
only one I like to use (all the light probes I have made my self are in this 
format).  This corresponds to the traditional spherical mapping of a 
rectangular image to a sphere (it doesn't require a special mapping type), 
the x coordinates correspond to the 'longitude' or east-west angle and the y 
coordinates correspond to the 'latitude' or north-south angle.  With 
lat-long maps, the rectangular image is basically stretched towards the 
poles, basically giving 'extra' information, the opposite of mirrorball.

Hope this is of help.  I know there are sites out there that can explain it 
better.  I'll try to recover some tomorrow if I can for you.

-tgq

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