[mapserver-users] Wanted: Projection for the reference map

woodbri at swoodbridge.com woodbri at swoodbridge.com
Wed Aug 7 16:35:44 EDT 2002

Interesting that this just came up because I ran into this same 
problem just yesterday. The problem I had was not so much wanting the 
reference map to be projected, but the fact that I had created it in 
one projection and had later changed the mapfile's projection 
parameter to a different projection. If the reference map is not 
created in the same projection as the mapfile projection is does not 
work. It would be nice to be able to say WHAT projection the 
reference map was made in so you don't have to recreate the reference 
map if you change the projection parameters on the mapfile.

On 7 Aug 2002 at 14:32, Steve Lime wrote:

> You've not missed anything, that support is not available. Nor do I see
> this being add in the near term due
> to the ton's of other work going on. This should be added as a feature
> request to Bugzilla so that the idea
> is not lost. That said, there are other possibilties:
> There is nothing that says that you can't use two different MapServer
> applications on the same page. In 
> reality you can mimic a reference map using a second mapping
> application. If you look closely at our
> Recreation Compass (http://www.dnr.state.mn.us/maps/compass.html)
> application you'll see we have 
> done just that. I wanted a reference map that would display a filled
> box sometimes, a marker symbol
> when the was too small, and nothing when the box was too large (eg. you
> didn't need the reference map).
> Prior to 3.6.1 you couldn't do this the the reference map object. The
> solution was to use a second
> little application. Worked like a charm and required on a small bit of
> javascript. I would imagine you could
> do the same thing with a reference map in a second projection. You'd
> just have to use lat/lon as a go
> between coordinate system. Worth a look if this is functionality you
> need ASAP.
> Steve
> Stephen Lime
> Data & Applications Manager
> Minnesota DNR
> 500 Lafayette Road
> St. Paul, MN 55155
> 651-297-2937
> >>> Havard Tveite <havard.tveite at ikf.nlh.no> 08/01/02 06:25AM >>>
> I can not find a possibility to describe a projection for the
> Reference Map Object in the Mapserver documentation. Have I
> overlooked something?
> In my opinion it would be very useful and practical to be
> able to use different projections for the reference map and
> the main map.
> This would, of course, in many cases lead to non-rectangular
> outlines on the reference map, so one would have to determine
> an appropriate level of detail for the outlines (from linear
> interpolation between the four corner points to a smooth
> rendering of the exact boundary curves). The lowest level
> of detail would imply four coordinate transformations while
> a high level of detail would lead to lots of coordinate
> transformations.
> The only effect I believe this would have on other elements
> is that "EXTENT" in the reference map object would have to
> be specified in the reference map coordinate system.
> -- 
> Håvard Tveite                      Phone:  +47 64948857
> Department of Mapping Sciences     Fax:    +47 64948856
> Agricultural University of Norway
> POBox 5034, N-1432 Ås, NORWAY    http://www.nlh.no/ikf/

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