[mapserver-users] Issue - Style constantly changes using Mapserver 7.6

[Jeff McKenna]

Hi Felix,

I have tested your case here locally on Windows with MS4W (this will be 
MS4W 5.0-beta3, that contains GDAL 3.4.1, MapServer 8.0dev, PROJ 8.2.1 etc).

I have used one of those GRIB2 files ( 
https://dd.weather.gc.ca/model_hrdps/continental/grib2/00/001/CMC_hrdps_continental_PTYPE_SFC_0_ps2.5km_2022022500_P001-00.grib2 
) and created a WMS service through MS4W, and then used QGIS 3.24 to add 
the WMS service, and zoomed-in 3 times : see the animated gif at 
https://pasteboard.co/N9LZcB9Nfgpc.gif

I don't see your issue.

Could you pick one GRIB2 file (the one that is shown in the extents of 
your image) and change your mapfile to use that single data file (no 
patterns) and reproduce your issue?

If yes, let us know here the exact filename that is shown in your image 
(and the exact extents to use).

Have a nice weekend,

-jeff





-- 
Jeff McKenna
GatewayGeo: Developers of MS4W, MapServer Consulting and Training
co-founder of FOSS4G
http://gatewaygeo.com/




On 2022-02-25 10:34 a.m., Laframboise,Felix (ECCC) wrote:
> Hi,
> 
> I am currently using GDAL 3.1.3 and Mapserver 7.6.2 on a Ubuntu machine. 
> I created a layer using a GRIB2 file as the source data.
> 
> When I tested the layer on QGIS 3.20, I noticed that it does not output 
> correctly. When I’m zooming or moving the viewing extent to visualize 
> the layer or data, the style constantly changes. I tested with WMS 
> GetMap requests through a browser and the output issue is still there. 
> See example GIF here: https://pasteboard.co/wAmyAUDyEeZs.gif 
> <https://pasteboard.co/wAmyAUDyEeZs.gif>
> 
> I validated the different classes (CLASS) in the style used in the 
> mapfile and everything seems to be in order. From what I understand, 
> Mapserver seems to do some interpolation, but I can’t quite understand 
> how it affects the output on that scale. I investigated and checked if 
> the source file was the issue, but from what I see it doesn’t seem like 
> it’s the case, as I tested with other data from another source file in 
> NetCDF, and the issue is still there.
> 
> I created a test case to show you the issue here:
> 
> ·Sample mapfile: https://pastebin.com/KC3UkR4m 
> <https://pastebin.com/KC3UkR4m>
> 
> ·GRIB2 Source file (available here: 
> https://dd.weather.gc.ca/model_hrdps/continental/grib2/00/001/ 
> <https://dd.weather.gc.ca/model_hrdps/continental/grib2/00/001/>) for 
> the source data (using following patterns) : 
> /CMC_hrdps_continental_PTYPE_SFC_0_ps2.5km_*.grib2/
> 
> Do you have an idea what could be the issue or how the interpolation 
> works, and how to solve this issue?
> 
> Thanks a lot in advance for your answer(s)!
> 
> Félix Laframboise
> 
> Félix Laframboise, B.Sc.
> 
> Développeur géospatial / Geospatial developer
> 
> Systèmes de données géospatiales et ouvertes
> 
> Geospatial and Open Data Systems
> 
> Service Météorologique du Canada
> 
> Meteorological Service of Canada
> 
> Environnement et Changement Climatique Canada
> 
> Environment and Climate Change Canada
> 
> felix.laframboise at ec.gc.ca <mailto:felix.laframboise at ec.gc.ca>
> 
> 
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