[MapServer-users] UVRASTER reprojection

[Seth G]

Hi Alistair,

The Mapfile and requests look fine to me, so this is likely an oversight in the implementation. 
It would be good to get this logged as an issue, ideally with a recreatable test case at https://github.com/MapServer/MapServer/issues. 

Seth

--
web:https://geographika.net & https://mapserverstudio.net
mastodon: @geographika at mastodon.social

On Mon, Oct 6, 2025, at 12:16 PM, Alistair Everett wrote:
> Hi Seth,
> 
> Thanks for your reply, we're just reprojecting the data. I'll take a closer look at the test case too, since it seems like that should be reprojecting from stereographic to geographic. I should also be able to pull together some test data in the next few days too, I can open an issue with it when I've put it together.
> 
> Here are a couple of example requests:
> 
> One in EPSG:4326
> localhost:8000/wms?REQUEST=GetMap&SERVICE=WMS&VERSION=1.3.0&FORMAT=image%2Fpng&STYLES=wind_barb&TRANSPARENT=TRUE&TIME=2025-10-06T07%3A00%3A00Z&DIM_PRESSURE=50.0&DIM_REFERENCE_TIME=2025-10-06T03%3A00%3A00Z&LAYERS=wind_pl_vector_meps_det_vdiv_2_5km_calculations&WIDTH=1304&HEIGHT=1504&CRS=EPSG%3A3857&BBOX=-2460529.2703191666%2C4596419.518351211%2C6809846.057963322%2C15288631.55342549
> 
> https://pasteboard.co/jI1eMKaj3PT1.png
> 
> This is one in EPSG:3411:
> localhost:8000/wms?REQUEST=GetMap&SERVICE=WMS&VERSION=1.3.0&FORMAT=image%2Fpng&STYLES=wind_barb&TRANSPARENT=TRUE&TIME=2025-10-06T16%3A00%3A00Z&DIM_PRESSURE=50.0&DIM_REFERENCE_TIME=2025-10-06T03%3A00%3A00Z&LAYERS=wind_pl_vector_meps_det_vdiv_2_5km_calculations&WIDTH=1438&HEIGHT=1504&CRS=EPSG%3A3411&BBOX=404935.5094684181%2C-3769428.4764078585%2C4977748.7994076125%2C1013263.5876175575
> 
> https://pasteboard.co/IHZjgXibtLyJ.png
> 
> Thanks,
> Alistair
> 
> 
> On Sun, 5 Oct 2025 at 10:00, Seth G <sethg at geographika.co.uk> wrote:
>> __
>> Hi Alistair,
>> 
>> Could you give an example request (I presume it is WMS?)? Are you rotating your map at all, or is it just the projection?
>> 
>> There are some tests which reproject a UVRASTER LAYER at https://github.com/MapServer/MapServer/blob/29e4ae81620a2c50201101c763df0b9d8d540b67/msautotest/wxs/wms_uvraster_map_reprojection.map
>> It sounds like an oversight, so if you are able to create a standalone test case, it would be worth opening an issue.
>> 
>> Seth
>> 
>> --
>> web:https://geographika.net & https://mapserverstudio.net
>> mastodon: @geographika at mastodon.social
>> 
>> On Fri, Oct 3, 2025, at 11:59 AM, Alistair Everett via MapServer-users wrote:
>>> Hi all,
>>> 
>>> I'm trying to use the UVRASTER connection to plot wind barbs. I noticed if I request the layer in a different projection the location of the arrows are reprojected but the angle, and presumably vector components, are not - rather they remain in the same direction relative to my screen. It's a little unclear from the documentation if this is the expected behaviour for UVRASTER or not? I included a pasteboard link to a screenshot to show what I mean, compare for example vectors in the corners of the data and you will see they point in the same direction relative to my screen, rather than being rotated to match the projection.
>>> 
>>> If this is expected, does anyone have any suggested ways of working around this?
>>> 
>>> If this is not expected, does anyone have any ideas what I've done wrong? I can provide some sample data if someone wants to try to reproduce.
>>> 
>>> I'm using: MapServer version 8.4.0 PROJ version 9.4 GDAL version 3.11 OUTPUT=PNG OUTPUT=JPEG SUPPORTS=PROJ SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=CAIRO SUPPORTS=ICONV SUPPORTS=FRIBIDI SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER SUPPORTS=OGCAPI_SERVER SUPPORTS=FASTCGI SUPPORTS=THREADS SUPPORTS=GEOS SUPPORTS=PBF INPUT=JPEG INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE INPUT=FLATGEOBUF
>>> 
>>> Screenshot: https://pasteboard.co/WTgbexDmQaAe.png
>>> 
>>> Example mapfile: https://pastebin.com/ibPc6gVK
>>> 
>>> Thanks,
>>> Alistair
>>> 
>>> -----------------------------
>>> Dr Alistair Everett
>>> Senioringeniør / Senior Software Engineer
>>> Avdeling for Geoutvikling
>>> 
>>> Phone: +47 939 68 985
>>> Email: alistair.everett at met.no
>>> 
>>> Meteorologisk Institutt,
>>> Henrik Mohns plass 1,
>>> 0313 Oslo
>>> -----------------------------
>>> *Dr Alistair Everett*
>>> Senioringeniør / Senior Software Engineer
>>> Avdeling for Geoutvikling
>>> 
>>> *Phone:* +47 939 68 985
>>> *Email:* alistair.everett at met.no <mailto:alistaire at met.no>
>>> 
>>> *Meteorologisk Institutt*,
>>> Henrik Mohns plass 1, 
>>> 0313 Oslo
>>> 
>>> _______________________________________________
>>> MapServer-users mailing list
>>> MapServer-users at lists.osgeo.org
>>> https://lists.osgeo.org/mailman/listinfo/mapserver-users
>>> 
>> 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/mapserver-users/attachments/20251011/0480aad5/attachment-0001.htm>