Hi WanMil, Gerd, On Sun, Jan 19, 2014 at 10:47:15AM -0800, GerdP wrote:
Hi WanMil,
I think your example is not valid. One rule in that wiki says: "If an endpoint is shared by more than two unclosed ways, it's ill formed and a closed polygon can't be reconstructed unambiguously." I think both end points of 3 are shared by three unclosed ways.
I agree with Gerd that the example is not valid:
11111111111111111111111111 1 1 1 22234444 1 1 2 3 4 1 1 2 3 4 1 1 22234444 1 1 1 11111111111111111111111111
MP: tags natural=forest Way 1: role=outer Way 2: role=inner, natrual=scrub Way 3: role=inner, natrual=scrub Way 4: role=inner, natrual=scrub
I think that this should be mapped with 3 multipolygon relations: MP1: natural=forest: role=outer: way1, role=inner: way2, way4 MP2: natural=scrub: role=outer: way2, way3 MP3: natural=scrub: role=outer: way3, way4 If you really meant natural=scrub for both 2+3 and 3+4, I think that this could be simplified by removing way 3 and merging ways 2 and 4. The example would make more sense if MP3 is tagged as natural=water, for instance. In my opinion, mkgmap should issue a warning for the duplicate way 3 for your example. It does not seem much different from a situation where two inner polygons are touching or intersecting each other. I think that the unambiguous way of mapping is to draw a bigger hole around the adjacent areas, like MP1 in the above example does. Marko