<br><br><div class="gmail_quote">2009/6/8 Frederik Ramm <span dir="ltr"><<a href="mailto:frederik@remote.org">frederik@remote.org</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi,<div class="im"><br>
<br>
Peter Dörrie wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
The current renderes wouldn't be able to handle it either and forcing 50+<br>
applications to change would be unappropriate.<br>
</blockquote>
<br></div>
Why, we're doing that all the time ;-)</blockquote><div><br>Yeah I thought so too, but this was one of the main arguments against my first try to establish something like this.<br> <br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
There are many unsolved questions here. For example: What happens if parts of the "ancient" world transcend your "fourth dimension", e.g. a contemporary secondary road uses a few bits of an ancient Roman road. They would surely share the same nodes, wouldn't they? But if someone then deletes the secondary road (which he downloaded without ever knowing that the Roman road also exists because that was shielded from him), he must not delete the nodes because they are still used by other objects...</blockquote>
<div><br>My angle on this is primarily the historical-genetic one. Taking your example:<br><br>1. Brutus Mappus maps this roman long distance road in 100 B.C he tags it correctly with highway=roman and surface=cobblestone. The road is used in that form for the better part of the next two millennia.<br>
<br>2. In the 19th century it gets some heavy usage and deteriorates. The local government decides to build a new road, which uses some of the same vectors the roman road used so far. The grat-great-great (etc) son of Mappus (John Maps) splits the road, tagging part of it as highway=disused and others as highway=construction.<br>
<br>3. The new highway is ready and John tags it as highway=primary<br><br>4. The same thing happens several times over until fake Steve finds a motorway, using some parts of the primary road, using some parts of the roman road (which by now is not longer visible in the landscape and has been tagged as historic).<br>
<br>Okay, what does this mean for whom?<br><br>Users: The normal user will see a rendering which shows "what is on the ground". -> Motorway and those parts of the primary road that still exist<br><br>Mappers: The normal mapper will see, what is relevant to him. -> Same as user and some additional tags (oneway, surface, maxspeed, etc.) plus perhaps those "disused" roads, as they may still be relevant to mapping. <br>
<br>Special interest person (scientist, etc): He gets the possibility of seeing exactly what he wants to see. The situation in 100 B.C? no problem. Ask the database about all disused / historic / etc objects? also no problem.<br>
<br>Different object sharing the same nodes over time (and changing them) is not a problem.<br><br><br><br>Greetings,<br><br>Peter<br></div></div>