Once you have downloaded and installed World Builder, here is the quickest set of menu operations to display a fully detailed world:
To create and view a detailed world map, use these steps:
The supercontinent cycle
When you use the File->New menu choice, World Builder creates a map of a world containing one large, irregularly shaped "supercontinent". The display uses the color spectrum to show altitude, where purple is land just above sea level, blue is higher, and red represents extremely high mountains. The supercontinent is surrounded by ocean, displayed as black.
To show the effect of a supercontinent breaking up into smaller continents and drifting apart, World Builder provides two Land->Drift menu choices. Each "timestep" simulates a million years of the slow continental movement. The "Drift 1" menu choice allows you to view the details of the movement, but to get results faster, use "Drift 10", which shows the effect of ten timesteps, ten million years, at once.
As a continent drifts across the map, the crust along the "leading edge" piles up to form mountains. After a few tens of millions of years, the forces causing the continent to drift slow down, and eventually reverse; the continent will begin to drift back the way it came. Because other rifts may have formed, causing other continents to drift too, the continent does not simply match back up with the original supercontinent. Instead, when continents collide, they slown each other down and pile up high mountains in the areas which begin to touch.
Often, after perhaps 50 million years, the continental fragments will drift back together to form a new supercontinent. The new supercontinent will have a much less regular shape and will contain mountains from the leading edge and collisions. Nonetheless, the same effects that caused the breakup of the original supercontinent will cause this one to break up, forming what has been referred to as the "supercontinent cycle".
Edit the results
When you see an arrangement of continents you like, use the Land->Anchor menu choice. This tells World Builder that continental drift is finished, and enables the Land->Edit submenu, which allow you to edit the continents. Once you have anchored the continents, you cannot go back and use the Drift menu choices.
Use the left, right, up, down menu choices to move the whole set of continents. In particular, if there are land masses touching the edge of the map, try to move them away. If the land masses only touch the center of the top edge, or the center of the bottom edge, this is not necessary; see The globe display for details.
If you would like to have a more mountainous map, use the Sharpen menu choice. Colors in the spectrum including green, yellow, orange and red will be treated as mountains. The Sharpen menu choice increases the "contrast" of the topography: it doesn't change the altitude of the coastline, but small mountains get taller and big mountains get a lot taller.
Continental drift sometimes produces "straight" coastlines, and rarely produces small islands. Use the Crumble menu choice to make more natural coastlines. As you might guess, this "eats away" at the coastline randomly to roughen the edges. If you don't like the effect, you can undo it and try again.
Drawing or modifying land maps
You can export and import GIF files containing the land data values. If you have an image editing tool which also reads and writes GIF files, you can draw your own land maps or make minor changes to land maps produced by World Builder. Once you have imported a land map, you can no longer use continental drift.
When World Builder imports a GIF file, it expects a very specific format. It uses the same format to export the GIF file, so you can use export to create an example. The file must be exactly 90 pixels by 90 pixels. The colors must all be shades of grey. Colors in a GIF file are stored as 8-bit values (0..255), and the color of each pixel is copied exactly into the altitude of the corresponding square. Sea level is 20, and high mountains are around 120.
To import your own map into World Builder, create the greyscale picture in your image editing tool and save it as a GIF. Then use the File->Import->Land menu choice, and enter the name of the file. You should see the land map appear in the display using the standard World Builder altitude colors. If the altitudes are not what you expected, perhaps the colors in the GIF file are not greys with values between 20 and 120.
To make minor changes in the altitudes of a land map, use the File->Export->Land menu choice to create a GIF. Edit it in your image editing tool, then use the File->Import->Land menu choice to bring it back in.
When you use the Climate->Compute menu choice, World Builder computes climate for the map. There are three steps: computing the seasonal temperature for each square on the map, computing the seasonal rainfall for each square, and finally using the average annual temperature and rainfall to determine which climatic type best describes each square on the map. Once you have displayed the climate, World Builder can optionally display rivers on the map.
You can control the results of the climate computation by using the optional Climate->Parameters dialog. There are several controls in this dialog, but the rainfall and temperature radio buttons are the ones you would use. You can make the world wetter, drier, hotter, or colder with these radio buttons. Use the View->Details menu choice to learn how to get more information about the climate in each square.
Temperature
World Builder computes the land temperature and ocean temperature for each latitude for each of four seasons. These values are based on several astrophysical formulae, and use some constants which are chosen to produce Earth-like values. For example, the tilt of the planet is set to 23 degrees, the value for Earth; this constant controls the difference between winter and summer temperatures. Once the land and water temperatures are computed, World Builder determines the seasonal temperature for each square by determining how many land squares are "near" the target square. Ocean temperatures vary less from season to season than land temperatures do, so inland squares will show a higher seasonal variation.
You can use the View->Temperature menu choice to display a temperature map, and you can focus on a single season with the Climate->Parameters dialog. Both are described in more detail in the Reference Manual.
Rainfall
There are several factors which influence how much rain falls in a given square. The primary effects are rising and falling air masses, and whether the prevailing winds come over oceans or are blocked by mountains. Therefore, seasonal air pressure and the direction of prevailing winds must be computed first, although World Builder does not display them. As with temperature, actual meterological formulae are used, with constants chosen to produce Earth-like values.
Climate
Once the average temperature and rainfall for a square are known, the
climate for the square is determined with a two-dimensional table:
V.Cold | Cold | Average | Hot | V.Hot | |
V.Dry | Tundra | Steppe | Steppe | Desert | Desert |
Dry | Tundra | Steppe | Forest | Forest | Desert |
Average | Tundra | Forest | Savannah | Savannah | Savannah |
Wet | Tundra | Forest | Savannah | Jungle | Jungle |
V.Wet | Tundra | Forest | Jungle | Jungle | Swamp |
Rivers
Once the average annual rainfall is known, World Builder can determine where rivers should be placed. Use the Climate->Add rivers menu choice. World Builder starts from the highest altitudes on the map, and determines the direction that rivers flow into lower altitudes. An amount of river flow is added to the lower altitude proportional to the amount of rainfall. As the rivers reach downwards, the flow grows; when a certain threshold is reached, World Builder draws black lines to indicate rivers which would be visible from orbit. Occasionally, rivers may flow into an area from which there is no exit; for example, into the center of a large crater-shaped formation. In this case, World Builder creates a lake in the middle of the region and rivers flow into the lake.
World Builder provides several ways to display the worlds it creates. You have already seen two main views: the altitude view used during continental drift, and the climate view displayed once World builder has computed the climate. You can also use a pop-up window to view the exact seasonal climate for each square; use the View->Details menu choice. You can display the world map as a globe. Once you have created a world you would like to keep, you can save the database.
Use the View->Globe menu choice to display the map as a globe. The Reference Manual describes the fields in this dialog in more detail. It may not be obvious at first how the globe relates to the flat map; this is because the flat map is stored in a special way to minimize the distortions needed to "warp" it onto a globe.
World Builder takes the flat map and divides it into eight triangles, as shown below. It may be helpful to think of the globe as an octahedron or eight-sided solid. Triangles 1-4 are warped into the northern hemisphere. The center of the top edge is the north pole, and the top left edge is actually adjacent to the top right edge. Similarly, the center of the bottom edge is the south pole, and the bottom left edge is adjacent to the bottom right edge. The equator runs through the center of the map, as you would expect; however, it also runs up and down the left and right edge. For example, the equator lies between the left edge of triangle 1 in the northern hemisphere, and the left edge of triangle 5 in the southern hemisphere.
World Builder home page Last updated: June 12, 1998 Feedback? email dallen@senteinc.com