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Map Generator Model v1.0
At Marks' suggestion, I've volunteered to
pick up on the map generator model. Since I've been unable to reach Gregor
to get his version, I've worked up a fairly simple model of my own. My
background is in cartography and natural resources, so I'll try to use
that to our benefit where possible. Following is a brief outline of what
the model will do. I'm still working on the (pseudo) code for the working
model; since I program in "ESRI Avenue" (also object oriented)
and not Java (yet) it is not a "true" code, but it shouldn't be
too tough to translate it later into something that will actually run.
Please note that this is still really rough, but I wanted to get something
posted to get some comments before I get too involved in hashing out the
details.
The basic idea is to simulate plate tectonics as closely as we can without
taking up a huge amount of processing time (simple, eh?).
This model starts off by creating a supercontinent, then fault lines are
arbitrarily defined by splitting the supercontinent up into x plates. 25%
of these plates (we can tinker with the ratio as needed) are labeled as
"sea" plates, while the rest are labeled as "land
plates". The purpose of the sea plates is to create seaside mountain
ranges (eg Chile) when the sea plates ram into the land plates.
Next, the plates are moved around a bit, forming mountain ranges where
they collide. A primitive climate model is used to determine the positions
of deserts and vegetation distributions. Finally rivers, resources, and
initial starting positions for the civs are selected based on certain
criteria for locations (FE you wouldn't stick a tribe on a mountain top -
usually!)
I know that a lot of people liked the idea of setting the sea level later
to create undersea trenches, etc. That would require a Digital Elevation
Model (DEM) or something similar to it for that type of model to work. I
have quite a bit of experience using DEM's for hydrological analysis in
the real world, and so haven't ruled out developing a model like that as
well...I just put it off for the sake of time now, since it would be
considerably more complicated. Any suggestions, gripes, etc are welcome!
I'll link the actual "code" on my own site when I get it written
up. Have at it!
I. Build Land Mass
A. Create Supercontinent
i. Select centroid
ii. Randomly build cells
around centroid
B. Create Faults
i. Select landmass
centroids
ii. Build landmasses
about centroids
iii. Randomly designate
sea plates (4:1 ratio of land plates to sea plates)
C. Move Landmasses
i. Select random
direction move each landmass
ii. Move landmasses
iii. Change terrain as
landmasses collide
D. Finalize Landmass positions
i. After n iterations,
end movement
ii. Remove sea plates
(they’re underwater anyway)
II. Climate Zones
A. 4 primary jet streams
i. Divide the map into 8
lateral bands (at equator, and halfway between the poles)
ii. Assign E-W and W-E
alternately to each band
B. Delineate climate zones
i. Assign polar/boreal
regions (bands 1,8)
ii. Assign temperate
regions (bands 2,3 and 6,7)
iii. Assign tropical
regions (bands 4,5)
III. Vegetation, Rivers, Resources, Tribes
A. Distribute vegetation
i. From “starting”
edge (depends on wind direction) move pointer across map
ii. Assign vegetation
according to terrain at pointer and according to 2 squares upwind)
iii. Move pointer to next
square
iv. Iterate until band is
vegetated
v. Move to next band and
repeat
vi. “Average” out
terrain at climate boundaries to avoid extreme transitions
B. Place rivers and lakes
i. Randomly place lakes
and seas (within climate limits)
ii. Randomly select
headwaters (50% of lakes will have a HW)
iii. Trace rivers from HW
to sea according to terrain
C. Distribute resources
i. Randomly assign
resource x,y coords
ii. Allocate resource at
random coords according to terrain and veg at location
D. Distribute starting tribes?
i. Randomly assign tribe
locations based on min distance from other tribes and veg/terrain limits
Just a quick update on the progress with the Map Gen Module: MCA and I
have begun collaborating on the coding of the model. I've worked out a
pretty detailed conceptual model that should be reasonably easy to
implement (MCA can verify if I'm correct in this assumption!)
You can add the following features to the
original proposal above:
1. Volcanoes produced near faults
2. Deep sea volcanoes to produce some islands
3. Atolls/island chains
4. Erosion effects during map development (FE wearing down of older
mountain ranges).
I have some pretty solid ideas on how to
implement these features, so we'll see If we can do everything in the outline, I think that we'll have the most
geographically/geologically accurate maps in any sim out there. MCA and
I'll keep everyone updated as we make progress to ensure the inflow of
fresh ideas that can only enhance the model.
Links:
Download the Source
Code or
Download the Source
Code + Compiled Classes
News from 9/13/99:
We now have pretty pictures of the map generator in action!
What you see in the snapshot are some of the the very first, bug-filled
elevation maps that have been generated, along with plate tectonic maps
(Step I in the model).
(To learn more about this
topic, click here)
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