This is discussion archived from a time before the current discussion method was installed.
Mister Six: Trope created by Silent Hunter.
SAMAS: Maybe it's just me, but shouldn't this trope be better served as a sub-category for the different types of environments found in video games? (Ice World, Lava World, etc...)? That was the first thing that came to mind when I saw the title.
About the Donut shaped world thing regarding maps that loop the north to the south, or the special stage in sonic...couldn't it just be a spherical world, but one that doesn't have two poles of cold climate. As in, you're crossing the equator twice as you go from the bottom to the top of the map and only one of the poles is the divide, the other is in the centre of the map?
OJ: If you could stretch the surface of a ball into rectangle (google Mercator Projection for examples), when going past the north edge of the map, you would pop out at north edge, facing south and at longitude opposite to the one you were before crossing the edge. Of course, that would require stretching a point (pole) to a long line (edge of the map) which would be really confusing. A donut-shaped world can be mapped into flat rectangle with much less geometrical distortion.
OJ: On a second thought... I think I understood what you mean. Something like Albers projection but extended to entire sphere so that one pole is in the middle of the map and another maps to the entire edges? Mind boggles.
Shawn: I still don't understand the logic of this trope. If you flew along the surface of a sphere and headed toward the top, you would circle back around to the bottom. Spheres are the same shape from the universal side to side and top to bottom. You cannot find the local "top" of a sphere, because it's all the same shape. Everyone just assumes that the portion of a sphere that's facing upward in the universe is the top, but what happens if you roll the sphere over? Does a new portion of the sphere suddenly become the top? I guess my main point is that a sphere, whether it is a soccer ball or a planet, is completely and totally equal across it's entire surface. So why do you expect a different reaction from flying up/down than from flying left/right?
ninjacrat: If you walk to the north pole in a videogame and then one further step forward, you warp instantly to the south pole.
I haven't tested it, but I expect a different outcome in real life.
Shawn: Maybe I need to see the actual map, but how do you know that you're warping to the south pole? Maybe the bottom edge of the map lines up with the top edge.
ninjacrat: If all the edges line up with their opposite, the shape they form is a torus, not a sphere. (This is easy to demonstrate — just get a rectangular cloth and try to fold it so the noth-south and east-west edges match up).
Shawn: Alright, I'm following the logic now. I'm used to doing 3D animation, and we frequently map square images over the surface of a sphere, so that was my point of reference. Thank you :)
kpk47: Deleted entry "What kind of game - more to the point, what kind of tool - would put Nottingham North of Greater Manchester?" because it's confusing without a title. Does anyone know what this was referring to?
Samiam: A "torus" geography is not a sphere because it's what math geeks call a different "topological surface". That other Wiki doesn’t explain it very well (they're notorious for having nay-to-impossible to read math articles), but there's a reasonable easy to follow explanation about all this stuff by following this pothole link
.
The reason why video game makers like using torical and cylinder geometries is because they're easy to program, and because we humans are more comfortable with two-dimensional flat surfaces. A toric surface is a two-dimensional flat surface everywhere so it's a common way to get rid of the invisible wall. Having a planet be a cylinder or torus instead of a sphere is an acceptable break from reality; Civilization games use a cylinder with invisible walls at the north or south poles (which makes sense; on earth, both poles are uninhabitable); the world map looks like the maps we used to see on the walls at school.
Danel: Are you sure about the Terranigma example? I seem to have a memory of it being properly round - going north over the pole and finding myself travelling south.
Elle Temporarily dumping the examples from the World Shapes split here for sorting.
Examples
Cylindrical, convex
- Most Civilization games. In custom game you can chose between toroid, cylindrical and flat.
- Star Control 2 had the various planet surfaces that you explore as the convex spherical type (despite seeing the planet floating there as a sphere in 3 different modes of the game, and being able to orbit and run into them during Ship-to-Ship combat).
Toroid
- Most any game with global travel and a square minimap.
- Final Fantasy VIII looks like it has a spherical map, but don't be fooled — travel too far west and you'll flip 180 degrees around the globe. It's just a toroidal world in disguise!
- This troper was always amused by the idea of the toroidal world in video games, since if you apply a little Fridge Logic, you'd determine that there would probably be an area in the middle of the torus which, due to shadows from the other parts of the planet, would be perpetually dark. Imagine this troper's amusement when Final Fantasy IX had a city named "Dark City Treno" which was in perpetual night. The game offered no explanation for why this would be, but this troper knows - Treno is in the middle of the donut!
- Depends on the axis of rotation; if the axis of rotation is a vertical perpendicular line going through the "donut hole" and not touching the torus, this would be a problem. If, however, the axis of rotation was a horizontal line going through the torus from on end to the other, this may not be a problem. Anyway, it doesn't matter; these games use a torus as the surface geometry for the world map but we should pretend the world is a sphere.
- Final Fantasy VIII looks like it has a spherical map, but don't be fooled — travel too far west and you'll flip 180 degrees around the globe. It's just a toroidal world in disguise!
- Tales Of Eternia (Tales of Destiny 2 in the US) has a universe consisting of two flat edge-warping worlds that face one another, so each world is effectively the other's sky. A sun dispensing variable illumination is lodged in an energy barrier that keeps the two worlds apart.
- A Michael Moorcock story used a similar idea. A Rodney Matthews illustration of the story was designed to be viewed both ways up, effectively giving two illustrations for the price of one.
- Populous: The Beginning, although it's drawn to look spherical.
- In the Planescape setting of Dungeons And Dragons, while the plane of the Outlands is, presumably, a flat world, its most interesting feature, the planar trade hub of Sigil, is built on the inside of a toroid that floats above the spire at the plane's center. the first books even had special rules for getting disoriented when you look up and see more city instead of sky.
- The "Lightside" world in Terranigma. Especially bad because it's supposed to be Earth. Yet, you can still fly from Antarctica immediately to Alaska by continuing South.
- Although you can at least say it is consistent; the "Darkside" world (which exists on the inside of the Earth) is similarly toroidal in nature (although there is no way for you to cross all the way around in any direction, as you cannot cross the lava seas).
- Some toroid-shaped worlds are seen briefly, but not visited, in Pastel Defender Heliotrope here.
- Castrovalva in the Doctor Who serial of the same name. Revealed as such when the pharmacist is asked to draw a map of the city, and marks his pharmacy as being at the top, and the bottom, and to the west, and to the east, although there is only one shop.
- Toroids are another popular shape for space stations in fiction, and some of those could be big enough to count as "worlds".
