[Mapserver-users] SHP file simplification

[Joe Bussell]

I believe that you may be working the problem from the wrong end.  We 
also have a considerable list of shapes which need rendering.  The 
solution that I chose was to use various levels of pre-rendered images. 
  I generate all my write-seldom, read-often data onto a set of flat 
images.  These are then used in the live server as raster backgrounds. 
If we did not do this we would not be able to render our traffic maps as 
fast as we do.  The trick was in defining a subset of scales that I 
would allow, and following through with calculations to insure new maps 
are rendered in one of those scales.

Cordially,

Joe Bussell
www.trafficdodger.com


Frédérique Boyer wrote:
> Hi all,
> 
> I'm using mapserver on a linux debian.
> I have all the maps of France (buy from IGN) and these maps are very precise
> and acurate.
> All works fine when I display a map with a distance of 1 to 50 kilometers.
> 
> My problem is when I have to display 100 or more kilometers.
> The vectors of roads are very numerous (>= 200.000) and the server takes
> more than 3 minutes to make my map.
> 
> I think, the reason is that the server reads all the vectors to transform
> them in a polyline before display.
> It coul'd be accelarated with a very little number of vectors.
> At this level, I don't use such a precision.
> 
> So, i have two solutions :
> Buy some maps with less precision  not very cheap :-(  )
> Find a tool able to simplify a shape file.
> 
> Someone knows if such a tool exist and where i can find it ??
> 
> Note : I don't have arcview.
> 
> Thank's a lot
> Frédérique
>