#2754 Add help reference to weather dialog

[Mariusz Matuszek]

Property /environment/wind-from-heading-deg was not properly updated upon reception of new METAR. Full description in this Forum thread: https://forum.flightgear.org/viewtopic.php?f=69&t=40711
Verified by one additional user during MP event.

[Mariusz Matuszek]

On closer verification it turned out to be a user error (wrong wind model used).
Since advanced weather engine is complex and full of (sometimes obscure) interrelated features I propose to add a help reference to weather dialog, with this patch:

diff --git a/gui/dialogs/weather.xml b/gui/dialogs/weather.xml
index 920103cc9..f6609693a 100644
--- a/gui/dialogs/weather.xml
+++ b/gui/dialogs/weather.xml
@@ -505,11 +505,16 @@

             <label>                          </label>
                                </text>


-          <empty>
+          <button>
             <row>0</row>
             <col>2</col>
-            <stretch>true</stretch>
-          </empty>
+            <legend>Weather help</legend>
+            <binding>
+              <command>open-browser</command>
+              <path>https://wiki.flightgear.org/Weather</path>
+              <!--path>Docs/README.local_weather.html</path-->
+            </binding>
+          </button>

                                <button>
             <row>0</row>

I first tried to open local help file, but Firefox security features prevented the action. Tried the same with a text mode browser (lynx) and it worked, so it must be FF and not directory permissions issue.. Opening our wiki seems more bullet-proof

[James Turner]

Yeah probably a good idea to add such a link. However, I think we have a way to build up a file:/// URL which Firefox should accept : do you think if we can make it work, the local docs or Wiki docs are better?

[Mariusz Matuszek]

I think the local doc would be preferred, as it is always present and available. That was my first try.
However I would suggest to include a reference to the wiki entry at the beginning of the local documentation file, with a comment, that additional/more recent information may be found there.

[James Turner]

Right, I agree. I'll check how build a correct a URL which hopefully Firefox accepts.

[Roman Ludwicki]

In my opinion, Docs/README.local_weather.html is very technical (describes the algorithms) and https://wiki.flightgear.org/Weather is more useful for someone who just wants to find out what the options do.

[James Turner]

Hmm, good point indeed. We do prefer local documents where possible, but equally I don't want to start snap-shotting the wiki into Docs, so probably an online link is best for now?

[Mariusz Matuszek]

Either that, or cross-linking in documents. That is, mentioning one in the other.
For example in local docs including, at the beginning, a statement "this document describes technical details of the Weather System. For more user oriented perspective please look at this Wiki entry: URL

Likewise, in the Wiki mention the local docs as a source for more technical knowledge.

[Gijs]

I have now added a link to the wiki article in the README per [f57e3b] . A link to the README can be found in the wiki article under https://wiki.flightgear.org/Weather#More_on_Advanced_Weather

[eatdirt]

Hi there,
I am landing here from https://forum.flightgear.org/viewtopic.php?f=69&t=40711&start=30#p404760.

On 2020.4 (and not on 2020.3), when we have live weather enable, all the rest being the default (wind constant), arriving from space we get a huge wind kick at high altitude (80000ft or so).

That triggers a lot of problems, the dynamical pressure being low, the Space Shuttle suffers from undamped strong oscillations that challenge the flight. Something changed in the way the winds are dealt in 2020.4, and I did not change any setting myself, up to have live weather on.

In the linked doc, it is said that wind constant in a tile should not create discontinuities at tiles' crossing, and the wind aloft is not set, so where this kick is coming from?

Thanks! Happy to test!

[eatdirt]

In case this is linked: https://sourceforge.net/p/flightgear/codetickets/2537/
I'll investigate!

[eatdirt]

A video showing it. Checking environment variables, it looks like this the wind direction which is discontinuous, it happens 2 times, at altitude 70kft and 50 kft (again the kick could be at tiles transition, i don't know).

windkick-SpaceShuttle-TAEM-20230122-233929.webm (curl.irmp.ucl.ac.be)

Edit: My two comments may not be related to this ticket about wind direction, but that could have interfered: https://sourceforge.net/p/flightgear/fgdata/merge-requests/308/