I generate lots of landuse polygons.
Landuse polygons normally are surrounded by a complete closed set of lines (e.g. highways, paths, other polygons…)
Is there any JOSM plugin to automatically generate a new polygon inside such a set of lines by duplicating and connecting all surrounding nodes with minimum permissible distance (to prevent “double point use”)?
the surrounding lines are normally much longer than the short pieces limiting the land area to be filled. For example if you wnat to generate a “farmland” area anjacent to a forrresst, the forest is often alare large multipolygon → coppying copies the whole objects
after cropping, the resulting polygon ist same size as the source lines. To fill in an area however, the polygon should be smaller. So you must adjust many points manualy
→ So the overall the time needed and error probability ist heighter than in manually creating athe polygon, possibly using a copy of only one side line with especially many points
I tried again, ans succeeded now:
There was a important hint missing: the parallel mode /scaling relative to polygon center works only with “simple, unbranched” polygons, so you must copy, crop and combine first, only then scaling works…
It is not the “semiautomatic” solution I imagine, but in some cases useful, I will try it out
I think so, because generating such polygons is a everyday task for generating landuse polygons.
If there is no exuisting solution, i might post as suggestion for such tool.
I the end, it is “not much more” than the “flood fill” tool of pixel graphixs programs.
from a point klicked, determine all surrounding line/polygon segments → if line is not closed, abort
determine all points conteining to this lines
connect and copy all this points
determine centre oft resulting polygon
change position of each point relatively to polygon center for distance x = scale area as in parallel mode
display polygo for further editing
I know, the problems arise in detail work, e.g. what if center of area lies outside of area in case of partly concave polygons…
I think it would accelerate creating landuse polygons a lot…