[Talk-us] Over-digitized imports?

Alan Mintz Alan_Mintz+OSM at Earthlink.Net
Fri Aug 20 04:24:59 BST 2010


I'm mapping in this area: 
http://www.openstreetmap.org/?lat=34.08242&lon=-118.639&zoom=17

Along the north side of the tertiary road (whose name is not rendered, but 
is Saddle Peak Road) is a state park polygon (Topanga State Park) imported 
from CASIL. In this small segment, the road is approximated with less than 
70 nodes, while the park polygon segment alongside uses over 1200. I've 
noticed similar "beauty" in other data from this source and others (like 
the Bakersfield data mentioned recently on the list).

Should imports make an effort to "un-smooth" such data to some extent, for 
the benefit of editing and rendering performance, storage, etc?

I suppose if one really wanted to not lose the detail, some calculation 
could be done during import to determine the radius and arc degrees that 
were used to create the curves in the first place and then tag those in 
some way (in case the day comes when we can feed that to the renderer 
instead of approximating curves with lines). Of course, it might make more 
sense to get the original curve data in this case instead of 
reverse-engineering it.

--
Alan Mintz <Alan_Mintz+OSM at Earthlink.net>




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