Le 18/03/2012 01:50, nemesis a écrit :
> Em 17/03/2012 20:18, Tim Cook escreveu:
>> Not completely off-topic, since it could be used as render-fodder.
>>
>> http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA15482
> 
> a 300MB image, woah. :)
> 

They use equirectangular projection to map the sphere on a rectangle.

It's probably ok to use map_type 1 of povray to put it back on a sphere.

Notice that they remapped rgb to 3 infrareds: 22, 12 and 3.4 microns.


(Equirectangular is a family: x = lambda.cos(phi_1), y = phi
lambda & phi are longitude & latitude)

plate carrée is usual, with phi_1 as 0, and a picture ratio of 2:1
Indeed, if unstretched, the picture ratio is 2.cos(phi_1), so you can
always get back to a know phi_1 with a simple unidirectional scale.

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