G'MIC just added different map projections to their filters, thus in GIMP you can now make those map gores via the pugin-in G'MIC.
Update your G'MIC filters and a new category will appear Map Projection select Sinuosidal Map, increase the number of Slices as you wish.
Note: To work(or you will get an error in the preview), your image should not have an alpha channel, thus before launching G'MIC ➤ remove the alpha channel from that layer
Note2: Discussion is over-there from David Tschumperlé post > https://discuss.pixls.us/t/two-new-filte...n/19890/12
Update your G'MIC filters and a new category will appear Map Projection select Sinuosidal Map, increase the number of Slices as you wish.
Note: To work(or you will get an error in the preview), your image should not have an alpha channel, thus before launching G'MIC ➤ remove the alpha channel from that layer
Note2: Discussion is over-there from David Tschumperlé post > https://discuss.pixls.us/t/two-new-filte...n/19890/12
Patrice