JOSM:rotate nodes

Hi all

Is there a way in JOSM to rotate a selection of nodes? Or alternatively, is there a way to mirror a set of nodes about a plane other than vertical?

I have traced half of the outline of a complicated but symmetrical building and would like to have the area similarly symmetrical. tracing by hand the other half will be time-consuming and also difficult to do accurately.



Try holding something like [Ctrl]+[Shift] (yes, only modifier-keys) and drag with the mouse. I’m not sure which combination it is, but the cursor will change to two arrows if you found the right one :wink:

Terrific! Thanks.


Hi, for mirroring there are two possibility’s depending on what you want to achieve.

One way is to use the mirror option in the tools menu. So to get a set (left and right hand sides), copy and paste your first half then mirror the second half, move the two halves together, join them up, you might have to rotate slightly to make ends line up. This will work even if the original half is not symmetrical (top to bottom).

Or, copy and paste your first half, then rotate the copy, move two halves together, join them up. This will only work properly if the original half is symmetrical (top to bottom).

Best to experiment first.


And one more thing, mirror option is available in expert mode only, which you can easily activate from view menu. :wink: