Un-Spherify by byRo

Let me start off by saying that I think that this is one of the coolest snippets around.

I can't really pinpoint it but I think there is a slight error in this one (or I shouldn't use it the way I want to).
If you look at the attached image you'll see a sphere on the left that is slightly noise distorted. If I run it through the unspherify offsets it looks ok... but when I offset it another 50% horizontally there is a slight difference in lightness (right image).

The weird thing is that when I unspherify and inmediately spherify again there is nothing wrong. But I want to do some horizontal offsets in between and that's when it goes wrong.

nb: seamless tiling is turned on

Try this...



Spherify - Un-Spherify - uberEDITION.ffxml

Sjeiti, thanks for the nice words and...
Kraellin, thanks for the helping hand.

Yes, there is a slight imprecision in the spherify / unspherify filters - however, as I remember, the problem was in the "spherify" part where there was a need to fabricate an arctan() function and not in the "unspherify" which uses basic sines and cosines.
The arctan() function cannot be fabricated exactly, so there was some simplification in the filter.
Also, as I remember (don't have access here),uberzev's versions are more precise.

In later discussions over at RuntimeDNA a more elegant solution (using arcsin() ) was posted. Not sure if I ought to post a link from here, though.

all the best,

Rô

Sjeiti and Uberzev I did have this some problem with this Ultra-Cool filter..But on some I did manage to hide it decent. This one the seam can still be seen but not as
much..Not the same problem but not really an issue..

http://www.filterforge.com/filters/1390-v8.html