Ari Torhamo schreef: > Hello, > > I have a question regarding the amount of nodes that one may use to draw > a road, and whether the amount of nodes used has a considerable effect > on the speed of the OpenStreetMap. > > I did my first edits to OSM a few days ago. I'll get a GPS device soon, > but so far my only edits have been adding street names and making roads > more accurate by adding more nodes to curves, etc. Following these > edits, another person who has edited the same area earlier, contacted me > and told me not to add unnecessary nodes to roads that he has made long > time ago and added that he has already removed the unnecessary nodes. > According to him using many nodes slows down the rendering and routing. > > This made me wonder, what really is the right amount of nodes to use, > when one want's the curves to be right and look really nice, but not to > cause any problems by this. Can nodes be added as long as there are > visible jaggies on the rendered map - even small ones - and just leave > out the ones which have no affect on rendering (like nodes on a straight > street)? It would be also good to know, if the speed of rendering and > routing is a factor that should be concidered? I see now that in a few > places I added some unnecessary nodes - for example I should have moved > existing ones instead of adding new ones. Or perhaps I just looked at > those curves too long - with full zoom - and those jaggies grew up in my > mind to something bigger than they were :-) On the other hand, in many > places I think that I made good changes and not many nodes should have > been removed. > > I searched for information on this matter around the OSM web site and > mailing lists, and found this page (see the section "Accuracy": > http://wiki.openstreetmap.org/index.php/Editing_Standards_and_Conventions > I would seem to me that my edits were relatively close to the example > given there. > > I took some screenshots of the changes in question, so that people would > get a better picture of what I'm talking about. I took screenshots of > four different places that I edited, and three different versions of > each of them. The version one shows the situation before my edits, the > second one after my edits, and the third one after the removal of nodes > by the original editor. The screenshots are here: > http://www.flickr.com/photos/[EMAIL PROTECTED]/sets/72157604611934407/ > (note that for some reason Flickr shows the pictures in a reverse > alphabetical order). The zoomlevel used in the images is 16. > > It would be nice to get comments from people who know more about what's > involved. > I would just like to add to the other replies that before (re)moving nodes you should look at their properties. Sometimes they are at a specific place for a reason (bus stop, crossing, etc)
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