Why are panoramas 2:1?

[Macker]

Hey chaps,

Just a quick question. Why are panoramas rendered out at a 2:0 ratio? Surely 360 views require the same amount of pixel information in every direction, no? Resulting in a square image?

Have I missed something completely fundamental?

[edit] typed wrong ratio.

[instinct]

Well there are different projections that can be used. I assume by "panoramas" you mean equirectangular projections which corresponds to "spherical" in max/vray.

In such an image you have one full circle (360°) on the x axis revolving around the viewport. On the y axis you only have 180 degrees (top to bottom). This leads to different amounts of distortion across the image. Which is - if i am not mistaken - why vray implemented elliptical sampling for spherical maps.

Cheers,
Thorsten

[AlexP]

360 degrees by 180 degrees

[Macker]

ahaaaa, of course it is. Very simple.