On Mon, 2010-12-06 at 21:18 +0000, Dave F. wrote: > On 06/12/2010 21:06, David Murn wrote: > > On Mon, 2010-12-06 at 20:56 +0000, Dave F. wrote: > > > >>> - which, if all they > >>> know about is the perimeter, is probably a good thing. > >> Eh? I thought you said you'd "love it" if it cut directly across an area?? > >> > >> They don't have to *follow* the perimeter just use it to find the best > >> exit& then join it to the entrance to the area with a straight line. > > And as was said during the thread, what happens if theres a lake, a > > building, a playground, etc in the middle of the straight line? > > As I said earlier in the thread, use multi-polygons. The router *should* > be able to get around it (see earlier in the thread about the maths > required to get around corners.
Okay, so are we going around the perimeter of the polygon or are we taking a straight line cutting directly across an area? > If it can't do this then it's not really fit for purpose & should be > avoided. Its 'not really fit' for your specific purpose, that doesnt mean you should be telling people to avoid it. Should we avoid all routers that dont take into account hgv and maxheight/maxwidth when routing, because its not fit for purpose of driving a big-rig? If you really want fuzzy routing in an application, feel free to add it, thats the whole point of opensource. However, please understand that most of us use routing software, expecting it not to try and take shortcuts across unmapped areas. The biggest problem is if an area is mapped, but the objects in that area arent. If the objects in the park were marked, including paths, then there would be no need for this discussion in the first place. This discussion came up with regards to routing across a park area that has paths but where no paths are mapped. > > What about if the 'straight line' crosses outside of the area, say for > > example if you had an L-shaped area. > > Have you actually read the whole of this thread? Yes, I did, infact I was one half of the monologue when the thread first started, so not only did I read the whole thread, I wrote half of it. Youre the first person to mention a straight line cutting across the area, since everyone explained the problems with it. David _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
