[crossfire] weather, lattitude, town location, and the world

[Anton Oussik]

On 11/11/05, Lalo Martins <
     lalo.martins at gmail.com
     > wrote:
>
      Now that some people seem to be working on salvaging the weather system...
     >
     
     >
      I remember one thing that was somewhat polemic about it, was the choice
     >
      of two *corners* of the map for the poles (nw and se IIRC), rather than
     >
      the north and south as would seem more reasonable.
     
Yes, it made the poles smaller, and the equator larger, as should be
on a circle-shaped thing it tried to emulate. Of course if you stuck
the diagonal ends together you would end up with something relembling
two cones put end to end, but it is a far better approximation to a
globe than a cyllinder.

>
      This does incidentally work remarkably well for Wolfsburg, which ends up
     >
      a hot, but miserably rainy town - as would be expected of a pirate port.
     >
       Scorn is also suitably temperate, and the "mushroom peninsula" is
     >
      tropical enough for its swamp.  However, it can be argued that
     >
      Brest/Britany is warmer than it should.  And I haven't yet seen
     >
      mikeusa's new region.
     >
     
     >
      Of use here could be Brendan's recent mathematical unit rationalization:
     >
      - 1 outdoor square = 1 chain
     >
      - the continent is approximately 1500 chains from N to S and from W to
     >
      E; about 18 miles, or 30 km.
     >
      - Earth (for comparison) is about 992716 chains from N to S (12409
     >
      miles, 19970 km), and 1992112 chains around the equator (24901 miles,
     >
      40075 km).
     >
      - So if Bigworld is more or less the same size as Earth (and Brendan is
     >
      correct), then this continent occupies about 0.075% of the W-E
     >
      circumference, and about 0.15% of the distance between poles.
     >
      - For another comparison, the Hawaiian island of O'ahu (where Honolulu
     >
      is located) is about 2500 chains W-E (32 miles, 51km) and 3280 chains
     >
      (41 miles, 66km).  Since it's not as neatly square-ish as "our"
     >
      continent, we can say they have roughly the same area.
     
I agree that Brendan's calculations make a lot of sense, and we are
pretending that we live on a planet whilst hardly occupying an island,
unless the planet is very very small, which means it is very dense and
quite close to the sun to get its heat. Since there is a lot of
radiation on it, there are many mutations, which lead to some strange
monsters we seem to be encountering. As for an athmosphere... the
planet is probably very dense. :)

>
      Hmm.  Maybe "bigworld" is not big at all :-P Brendan's calculations
     >
      still make sense to me generally, except that now I'm thinking about
     >
      one-chain-wide mountains and finding them a bit silly.  But that can
     >
      pass, since those are relatively rare.
     
Such rock formations may actually be possible, wih a hard surface and
wind and such. Since the planet is not Earth and since we are willing
to accept teleportation and beds to reality, then why not small
naturally occuring rock formations?

>
      On the other hand, fantasy worlds don't *have* to be the same size as
     >
      Earth.  (They don't even have to be the same shape... a disc, with the
     >
      "pole" at the center, or a ring, or even the "normal" shape but with us
     >
      in the inside rather than outside, are all heard of; and many fantasy
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      worlds are simply flat - some discoid, some rectangular.  So there.  But
     >
      we'd better stick with almost-spherical, if for no other reason, because
     >
      changing the shape would probably require rethinking part of the weather
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      code.  On the other hand, a rectangular flat world avoids problems of
     >
      projection, in case we end up mapping the whole surface.)
     
On a scale a player would be playing at a 2D approximation would
suffice. If a whole surface is mapped, it would probably be best to
store tiles as 2D polar coordinates on the surface of a sphere, and
when a player enters worldmap extract and send the appropriate
coordinate tiles to the player. That way only the parts of the hugemap
that players are on would need to be stored in memory. On the other
hand the data structure we would need to store tile coordinates and
code to approximate them to generate a 2D projection of what player
sees may be both CPU and memory consuming. Then seas could be
auto-generated depending on the altitude, and global warming/cooling
flooding/deserting/freezing could take its normal cause.

Having a true globe would open up new weather and other effects, such
as calculating weather by determining the amount of light that hits
the surface by using ray tracing algorithm, and from there calculating
how weather changes. This could result in a very realistic weather
model, but probably too computationally intensive for an adventure
game (not a weather, economy, eco-system simulator with elements of
real time strategy, sim city, the sims, and tux racer). However you
would then be able to set rotation speed, sun brightnes, and planetary
mass to inflence all other game elements in a consistent fashion. Umm,
you probably can already with minor modifications.

>
      For consistency reasons (since we don't have contact with other
     >
      continents, and what with dragons and magic, I believe we have more than
     >
      enough "technology" to do that), I can see two possibilities:
     >
     
     >
      1 - the world is *much* smaller than Earth - the maps we have (in
     >
      /world) cover from 10% to half its area.  People don't go to the "old
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      continent" because they don't want to (maybe they're afraid of the "old
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      empire", or maybe the "old empire" indeed has powerful defenses, or
     >
      maybe it was overtaken by monsters.)
     
Seems reasonable. From time to time you can even introduce random
attacks by somewhat powerful monstes from old empire who try to take
over your continent to re-inforce the belief. Also this model does not
violate the current weather system in any way, so I like it. Besides
the planet that is 80mi in circumferance is still a whole deal bigger
with what the little prince had to make do with :-)

>
      2 - the world is mostly water-covered; there may be other inhabited
     >
      continents out there, but the chance of a traveller actually finding it
     >
      is so small, that nobody bothers to try.  Nobody knows exactly where the
     >
      "old empire" is supposed to be; if anyone ever found it, they didn't
     >
      come back.  The world could still be somewhat smaller than Earth, just
     >
      to give us enough weather variation in our continent; if we make the
     >
      world 1% the dimensions of Earth, then our continent would be
     >
      proportionally about the size of Australia.  (I'd make it slightly
     >
      bigger than that; what about 15000 chains from pole to pole - so our
     >
      continent is a neat exact 10% - and 32000 around the equator?)
     
This model as I understand it would need some modification to the
weather code, to get rid of the extremes we seem to be suffering at
the poles and the equator region.