Most modules in darktable are working on changing pixels color, lightness, etc. Few modules are moving pixels and when they do they are doing it in a very constraint way like to rotate, fix the lens’ distortions or remove spots. The liquify module offer more ways to move pixels around by applying some free style distortions to parts of the image. There is three tools to help doing that: point line curve Each tool is based on nodes.
posted on by pascalobry