I am doing some topology testing using Grass in QGIS. I am hoping to snap nodes to eliminate gaps between polygons. When I use the v.clean.snap function in Grass it does not work on polygons. When I test it on lines it completes the tasks as I was hoping. Does anyone know of a way to run v.clean.snap or a similar function in Grass on Polygons? Attached are two screen grabs showing the errors as polygons, and the fix as a line.Grass v.clean.snap with polygons

1 Answer 1


mhm, not sure. from the grass manual for v.clean ... snap: snap lines to vertex in threshold It says lines, not boundaries. Don't know how semantically over-correct those manuals are, but a boundary of a polygon isn't a line i think.

Did you try using the snapping while importing the layer to grass? Thats what i tend to do (advanced options of v.in.ogr).

an the manual there says:

Snapping threshold for boundaries
'-1' for no snap

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.