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

[Laframboise,Felix (ECCC)]

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

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


·       GRIB2 Source file (available here: 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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