02-12-2020, 12:58 PM
I do not know of any workaround. As far as I know this is not possible. The new Warp is a transform tool and a GEGL operation, not a paint tool.
There have been enhancement requests like this one for a shift-click Warp in a straight line https://gitlab.gnome.org/GNOME/gimp/issues/3515
You can always add a 'wish' for Warp-along-a-path on that site.
There might be other ways depending on what is required. This for example using a gmic http://www.gmic.eu warp-map filter where the map is a fuzzy line. https://i.imgur.com/1eESQ4r.jpg
There have been enhancement requests like this one for a shift-click Warp in a straight line https://gitlab.gnome.org/GNOME/gimp/issues/3515
You can always add a 'wish' for Warp-along-a-path on that site.
There might be other ways depending on what is required. This for example using a gmic http://www.gmic.eu warp-map filter where the map is a fuzzy line. https://i.imgur.com/1eESQ4r.jpg