Basically what I'm looking for is an algorithm or an extension similar to least cost analysis, but instead of using points on top of a DEM to create a path (line vector) between the points, I whish to create a Thiessen (Voronoi) polygons (centered on points), whose spatial limits would be defined by the DEM.
So for example, a border between 2 polygons would be determined by the least cost analysis between the center points of the 2 polygons. The aim would then be, instead of getting a set of Thiessen polygons with arrow-straight borders (like in the pic), to create a set of polygons whose limits would be determined by the DEM (relief). Sort of like a watershed centered on a single point.
Btw, it would be great if there was a solution applicable in QGIS.
Thanks!