[mapserver-users] GEOMTRANSFORM definition causing an error

[Fawcett, David (MNIT)]

If your map units are in feet, then your map extent will be a 360 foot x 180 foot box.

If you want your map output to be in feet, you will  need to find an appropriate spatial reference system that uses feet as its units.  You should then set your map (output) projection to that spatial reference system.  

In MapServer, the map units need to match the map projection and the map extent needs to be expressed in those map units.

When you get to a production app, you will likely want to project/transform your input dataset ahead of time so you don't have the additional overhead of projecting the features on every map request.  

As I am thinking about it.  If you are applying a layer-level geomtransform and you want to use feet as the units, you may need to pre-project your data to a feet-based srs ahead of time.  This is assuming that geomtransform uses the units of the layer SRS, not the map SRS.  (Which could be a flawed assumption.)  My MapServer knowledge is fairly old and I have never used geomtransform, but map extent and map units have been around forever....

David.

-----Original Message-----
From: mapserver-users-bounces at lists.osgeo.org [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of tday
Sent: Thursday, September 26, 2013 12:49 PM
To: mapserver-users at lists.osgeo.org
Subject: Re: [mapserver-users] GEOMTRANSFORM definition causing an error

I wish to create a 150 foot buffer and  MAP UNITs are set to FEET. 

Are you implying that buffer units must be specified another way?



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