This Ruby road using this pattern (and tiled to size) took 17s only near 3 year old PC. Again, the preview was near instantaneous (and quite accurate).

That Dipole mapping in picture doesn't have a setting. I tried putting it in as formula but got a different result. Pity I flunked Algebra.

Not only speed performance for this filter improved (windows), it is a general improvement in speed for G'MIC (windows). So for windows users the new build from Samj and David is a must. I'm flabbergasted.

Copy-pasting the dipole formula in the custom formula field works for me, it gives exactly the same result :

Thanks Ronounours, I hadn't seen that I had to change mapping to "custom mapping" and then enter formula..

3rd try

For a larger image
https://www.flickr.com/photos/115367823 ... 5/sizes/o/

selected a couple areas in a picture and it only mapped them

Also found that custom map changed when clicking update for presets

Very cool! =D

Thanks Rod. I did another using the pink flowers but it was too big to put here. So I uploaded iot to flickr
https://www.flickr.com/photos/115367823 ... 5/sizes/o/
Here is one I did tonight with my puffball. I also ran array mirror on it

Tried another one using fire
Don't know where the error in the image is because it is showing in Flickr
After running conformal maps I ran array - mirror, rain drops, and textured glass. You may only see the smaller deformations if you enlarge it.
This is only half the size, I cannot 'open' the original. https://www.flickr.com/photos/115367823 ... 0/sizes/k/