Globe-like world map.

[Truman]

Civ 3 definitely needs a world map that acts more like it's on a spherical surface. It wouldn't be hard to implement on a 2 dimensional map.

Assume X and Y coordinates for each tile on the map. For each tile on the northern and southern map border (identified by TileY=1 or TileY = MapY (the height of the map at creation)), the departure tile and appearance tile could be set as follows:

IF DepartureTileX > MapWidth/2 THEN ArrivalTileX = DepartureTileX - (MapWidth/2)

IF DepartureTileX < MapWidth/2 THEN ArrivalTileX = DepartureTileX + (MapWidth/2)

The Y coordinate would remain the same, so that going south at the southern edge of the map would put you at the douthern edge, but halfway across the width of the map. Same deal with going north at the northern edge.

[airdrik]

This has been discussed several times. I even e-mailed someone at firaxis about it, but he says they haven't gotten to discussing it themselves, so the topic is in the air.

As for my suggestion: instead of x and y, you could have degrees latitude and degrees longitude. as you get closer to the poles, some tiles would merge until the poles are 1 tile w/4 tiles around them. Problem with this is what to do with the tiles being merged? The way I see it is you have the tiles being trapizoidal and when two tiles merge, they become one double size trapizoid. This just wouldn't look very nice on the game, but it would work.

Another Idea is that instead on squares, they could be triangles. Then when they merge, instead of 6 tiles meeting at a point you have 5. You can hardly tell the difference if you don't pay attention that much. This would provide for an almost spherical map (you could even have mountains with larger surface areas be made of more tiles by just adding a few triangles to the base and building from there). Problem with this is it's so different from what we know, and how do you do coordinates? Generating a map like this would take extra effort as well.

[Dauphin]

You could probably work the graphics out ok for a spherical map. Imagine full out scene of the earth in space. You can sort the graphics so that as you zoom in the image becomes less curved. its pretty standard.

For the map setup. Imagine a football (soccer ball for the yanks ). It is made up of 60(?) tessellating tiles, a mixture of pentagons and hexagons. It is also symmetric and close to spherical even when the hexagons are flat. There are an increasing series of such shapes (Platonic shapes for example tetrahedron, cube, dodecahedron...). You'd want shapes with ~10,000 tiles sides of course

If you use these shapes as the source map parameters then a spherically accurate map can be made with each tile representing the same size area. If you auto centre on any region of the map it will look flat provided you weren't zoomed out too far. If the graphics are done well the shape of the tile need not be revealed eg a mix of hexagon to pentagons.

The radar map would be replaced with a globe at a suitable zoom level.

You'd have to program the new co-ordinate system as polars and not Cartesian. ie Longitude and Latitude not x and y.

I hope this makes sense to you all.

[airdrik]

quote: Originally posted by Big Crunch on 11-30-2000 10:56 PM You could probably work the graphics out ok for a spherical map. Imagine full out scene of the earth in space. You can sort the graphics so that as you zoom in the image becomes less curved. its pretty standard. For the map setup. Imagine a football (soccer ball for the yanks ). It is made up of 60(?) tessellating tiles, a mixture of pentagons and hexagons. It is also symmetric and close to spherical even when the hexagons are flat. There are an increasing series of such shapes (Platonic shapes for example tetrahedron, cube, dodecahedron...). You'd want shapes with ~10,000 tiles sides of course If you use these shapes as the source map parameters then a spherically accurate map can be made with each tile representing the same size area. If you auto centre on any region of the map it will look flat provided you weren't zoomed out too far. If the graphics are done well the shape of the tile need not be revealed eg a mix of hexagon to pentagons. The radar map would be replaced with a globe at a suitable zoom level. You'd have to program the new co-ordinate system as polars and not Cartesian. ie Longitude and Latitude not x and y. I hope this makes sense to you all.

This would work best with triangles as you would only have one shape to deal with (one picture for each terrain type). But the map shouldn't be flat in the essense of no tiles stick out: what about mountains, bumps in the earth's surface.

Make the view slightly tilted so you can see the difference in elivation. You could turn this off so that you would look directly at the surface.

[Dauphin]

quote: But the map shouldn't be flat in the essense of no tiles stick out: what about mountains, bumps in the earth's surface. Make the view slightly tilted so you can see the difference in elivation. You could turn this off so that you would look directly at the surface.

When I say flat i mean as in opposed to spherical. Of course there are elevations .etc. on the planet, but compared to the shape of the earth its miniscule. Mountains are less than 10 km high and the earth is ~6400km in radius (and slightly squashed like a tangerine).

When meaning treat the map as flat that is to say you can treat the map graphics as a standard x-y map with elevations, isometric views and whatever else you want. Basically when at suitable zoom levels you can make a flat earth approximation.

[Zer0_T0lerance]

I have mentioned this idea before in a similiar thread. If this idea is implemented into Civ3, then it should make the maps more accurate because of the shape of a sphere; ie, the distance from east to west would be shorter at the poles than at the equator.

So, in order to size spherical maps you will probably need to input the circumference of the planet. You'll need to input both horizontal and vertical circumference because in reality, the earth is NOT a perfect sphere.

That's just my two cents.


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Zero (formerly jrhughes98)

[zyxpsilon]

Let's stick to the "perfect" sphere, allright!
LONG-LAT x-y coordinates is a mighty nice approach too (feel much more like down to Earth).
Isometric is a 45^ Viewer standpoint.
"God-like" is much more -overhead-.
How about 60^ perspective vision to -witness the action- ?

[airdrik]

Not to be harping on you, but you cannot do squares in a perfect sphere. three squares joined at a corner makes a half-cube, four makes a flat surface. It just doesn't work. That is why other polygons are suggested, my personal favorite being the triangle because you only need one picture per terrain type, rather than one for hexagons and one for pentagons because you need both in order to make a spherical shape.

Big Crunch: That's what I was meaning when saying not flat, flat as in not curved at the edges, but not flat because of the mountians.

The way the view is done doesn't really matter as long as it is a good one, so you don't really need to put much thought into what angle to do the view.

[Dauphin]

You certainly wouldn't notice the triangles weren't flat. 10,000 flat triangles would still make a very convincing sphere.

However, the thing about equilaterial triangles is that they can only make regular hexagons when put together. If hexagons alone can't make perfect spheres, then identical triangles alone won't make a perfect sphere. Thats why pentagons are interspersed with hexagons in footballs.
[This message has been edited by Big Crunch (edited December 02, 2000).]

[Zer0_T0lerance]

To add to my previous post, I think even flat maps should be a spherical shape, but they will only be part of a sphere and not a whole one. This adds realism by allowing even flat maps to be geographically accurate.


I'd also like to stress the option to have spherical maps turned off. I've seen a lot scenarios in Civ2 that are space scenarios with space tiles in them. You wouldn't want a map of space to be a sphere, would you? NOT ME!!!


There's another two cents.


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Zero (formerly jrhughes98)
[This message has been edited by Zero_Tolerance (edited December 01, 2000).]

[zyxpsilon]

quote: Originally posted by airdrik on 12-01-2000 11:50 AM cannot do squares in a perfect sphere.

Polygons are easier to manage "efficiently" on a perfect sphere than if -say- a programmer must take into account the nightmaring parametric variables that must be used for an ellipsoidal globe (Earth).
But "squares" can be BENT a little to squeeze into a triangle or even a diamond (isometric by the way).
Knowing that, a 'perfect' sphere can be represented faster.

[Dauphin]

I've recently discovered that any near perfect sphere can be made out of just 12 pentagons and a whole load of hexagons. The even better bit is that it is symmetric (the hexagons radiate out concentrically from the pentagons), and so the co-ordinate system could be based around the pentagons location.

The downside would be gameplay, in knowing where the pentagon spheres are but there are only 12!. Not all the hexagons are regular but are close enough to it so that only one graphic need be made per terrain type.

The problem with triangle made spheres is they are too "rough" and jut in and ot over the surface. The Satellite Earth at EPCOT is an example.

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Pax Vobis.

[N35t0r]

yeah, i like the triangle thing.

They wouldn't be exactly flat triangles, but a bit bulged up in the center. (like, if you cut the earth along six lines, each at 90° from each other)

[airdrik]

How about we pick one shape that would be the shape tiled over the whole map, and have it 'stretched' to fit the curves of the earth. You don't have to use regular shapes, though a regular shape would be used as the texture of those tiles for the different terrains. One picture/terrain. I'm for triangles because they are the easiest to stretch (three sides, three corners, three parameters to alter) and they would fit the surface easier because they are the smallest shape.

[Dauphin]

It depends on whats easiest to program in, but the choice would be good. Certain shapes may suit different people and gameplay. My penchant for hexagons comes from playing Historyline by Bluebyte several years ago.
[This message has been edited by Big Crunch (edited December 03, 2000).]