Melchior FRANZ wrote:
> * Ampere K. Hardraade -- Thursday 17 November 2005 01:50:
>
>>On November 16, 2005 05:37 pm, Melchior FRANZ wrote:
>>
>>>* Josh Babcock -- Wednesday 16 November 2005 23:25:
>>>
>>>>I considered using a Nasal script, but I don't know how the
>>>>script would know when the winter textures are being used.
>>>
>>> if (getprop("/sim/startup/season") == "winter") { ?? }
>
>
>>I believe you would need more checkings. We don't have snow all the time in
>>winter.
>
>
> He didn't ask when we have snow in winter, but when fgfs uses
> winter textures.
>
> m.
>
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Yes, often what's in the sky and what's on the ground are different.
Sunny and warm cloudless days with 3 feet of snow for instance. METAR
can take care of visibility and what the air feels like, but it doesn't
tell you what the world *looks* like. In other words, I'm talking about
cool (get it?) eye candy.
Now, I thought I sent another e-mail, but I don't see it anywhere. Maybe
it was lost before I sent it when X crashed on me last night. Anyway,
The upshot was this:
1. Global annual snowfall data is available, there are a few places on
the net that reference these data sets.
2. Someone (like me) could create a database with an entry for each
10x10 chunk (or 5x5, that's only about 2500 entries, right?) that
contains the probability of there being a certain amount of snow on the
ground on the winter solstice, and the standard deviation.
3. Based on the current chunks probability of snow on the current date
(in terms of time delta from the solstice) and possibly the current
temperature and a little random number to make it interesting, decide if
there is going to be accumulation today. Do it whenever the current
chunk or changes or the sim date crosses midnight.
4. Export a property with the result (yea/nay)
5. Trigger whatever it is in the scenegraph renderer that swaps the
textures. (Perhaps this bit can be smart enough to blend the textures
slowly over time for the chunk boundaries, say in a background thread.
At midnight, don't bother, just swap them you probably won't see it anyway)
6. Ski.
This should result in the kind of behavior you see in real life, such as
skiers in California wearing short sleeves, or a cold high arid desert
that has a very low temperature, but no accumulation, like in central Asia.
Trivia: the driest spot on earth, with absolutely zero precip, is in
the Trans Antarctic mountain range. The average continental precip is
less than one inch of snow. Not rain, but snow! 2% of the continent has
no snow pack.
You could also force snow textures if you start out without any, and
it's below freezing, and METAR has been reporting snowfall for at least
an hour or two, but that's getting a bit complicated. Or on Dec. 25. It
should always be snowy on the 25th. (Yes, I know hemispherical
discrimination)
Josh
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