Design decision - Rivers - In square or on edge of square?

[Richard Bruns]

I think that we should make the models flexible enough to handle both cases, if possible. With hexagonal tiles, having rivers run between the squares is a very good way to go. (Of course, that assumes that we will have the option to use hexes.) I always liked the structure of hexagonal wargame maps with rivers between tiles and roads in tiles. That way, natural barriers and the importance of bridges can be modeled much better, and the graphics look good.

But I have been convinced that with square tiles, it would not be as good. All of the bends are 90 degrees and they can flow in only four directions. But if they are in the tile, they can go eight directions and they can be made to look better.

The modeling aspect isn't really too hard. We can simply assume that any tile bordering the river has a river inside it.

[Lord God Jinnai]

I say in square, mainly because it allows for more natural looking rivers since we will be using square tiles.

[Mark_Everson]

Design decision - Rivers - In square or on edge of square?

Where rivers go has come up in a couple of threads recently. I have reviewed what's in the old threads as well as the new ones. (If you want to do so also, just search on 'river'. The OO modeling thread is especially rich on this topic.

I think that the majority of opinion in the past was on the side of rivers being in a square, as they are in Civ2.

In-square benefits:
Simpler for all square-based modeling / coding Including Ecology, Economy (cities are frequently built on rivers and its simpler to have a city in a single square), and the current coding architecture in which rivers are associtated with Terrain of a particular square.

Between-square benefits:
Military - attacking across a river implemented
Borders - using river for country borders is a natural

Some proponents for each side think theirs looks better

I think we should make rivers in-square (the way it has been assumed for quite some time) based on the many benefits of that approach for a wide variety of models. But since we all have a stake in Clash I wanted to give people room for commenting on it before we lock in this finally.

Please put your comments in below, and feel free to copy your posts from other threads to further the discussion!

[LDiCesare]

quote: Originally posted by Mark_Everson on 04-18-2001 12:20 PM Between-square benefits: Military - attacking across a river implemented

Actually, I can as (if not more) easily implement this with in-square rivers: It gives a terrain bonus to defense. Neat and simple.
I'm in favor of in-square because so many cities are built on rivers (Paris even is represented by a boat in heraldry although it is far from any sea for instance).

[Mark_Everson]

Hi Laurent:

The problem with in-square rivers giving a terrain bonus to defense is that a city on a river always gets the bonus no matter what side of the river the city is on, which doesn't make any sense. If one kept track of where the city actually was, it should FE only get a bonus for troops attacking from the west, but not the east. But I don't think this lack of reality in the system is a big problem. Just one of the many trade-offs needed to make a game

[Simon Loverix]

Maybe we could have a special combat mode, like Master of Magic, Imperialism and (I think) CtP. There we could put the rivers on edges.

On the main map I would rather treat rivers like roads, because people use them as main traffic channels when no roads are present fe middle age Europe. Even then we could place a city relative to rivers in a square by dividing the square in eight quadrants and storing the appr. number.. But that probably is more work than it's worth.


[This message has been edited by Simon Loverix (edited April 20, 2001).]

[Gary Thomas]

In view of the size of a map square, any rivers that appear would be rather major ones. From where I live, crossing a map square, a spread of 65km I understand, would involve crossing about five rivers large enough that you could not wade them.

Hence one would assume that every map square (apart from pathological terrain like desert) would have quite a few rivers in it.

If, in a transect across our map, one square in five (say) had a river, we are effectively selecting the largest 4% of rivers to show on the map.

I suppose a study of physical geography would indicate the expected size of such a river, but I rather suspect that it would fill most of a square, allowing for tributaries, meanderings, and related lagoons.

If that is the case, the problem goes away - rivers fill the square as far as movement and so forth is concerned. So they are in the middle and on the edges. Of course for aesthetic reasons they wouldn't look like that in the actual representation, there would be a bit of land at the edges.

Cheers

[This message has been edited by Gary Thomas (edited April 20, 2001).]

[axi]

I'm for rivers inside squares. I also feel that some rivers should be navigable for some length and the navigable parts have different graphics than the other ones. This way we may eventually have the option of players building canals. These squares should be like coastal squares and allow for both land and naval TFs to move on them.

------------------
"In a time of universal deceit, telling the truth is a revolutionary act."
George Orwell

[Mark_Everson]

OK, thanks everyone. I believe this is a reasonbly strong concensus for in-square rivers. We can possibly put in the options that Richard mentioned for between-square rivers in Clash 2.3 .

[Gary Thomas]

As I have mentioned before, I am an advocate of edge rivers. So I am going to have another shot at convincing people.

The following arguments have been presented in favour of in square:

• Looks more natural


• Can go in eight directions


• Simpler to build cities on rivers.


• Rivers can function as roads

Here are some arguments for on edge:

• Clearer on the map


• Drawing doesn't conflict with roads or canals


• Bridges become possible


• Natural barriers


• Defensive barriers


• Political boundaries

One of the problems that arises is that rivers are both barriers and highways, with diametrically opposed requirements.

Highway versus barrier

Having the river in square essentially eliminates the river as barrier option. An important part of the barrier effect depends on which side of the river you are on.

The only way to implement that with the in square option is to remember where each TF came from, and make assumptions accordingly. This is unsatisfactory.

The implementation of river as barrier in the on edge option is immediate and obvious. All the physical, military and political implications of river as barrier as easily implemented.

With the river on edge, using the river as a highway is still possible - any square with a river on its edge, can be reach another square with the same river on its edge using the river. This also allows crossing the river in the process. So the on edge option does not seriously limit the river as highway possibility.

Looks more natural versus clearer on the map

I agree that in square can be made to look more natural, but only at a cost of having the river on top of (or underneath) other terrain such as roads or cities. Rivers on edge are clearly visible and do not obscure or get obscured by other terrain. The square edges are not actually used for anything else - they tend to be open territory on the map.

I am not immediately sure of the gain from being able to go in eight directions, apart from the aesthetic one. It does give eight ways of covering up other terrain features.

Cities on rivers

One must bear in mind that the visible rivers are really big ones. Very few cities straddle such rivers (Budapest, perhaps, but not London or Paris). In any case, any cities will be at some rather undefined location in a 100 km x 100 km square. Why not at the edge, near the river? Alternatively the city could be on some smaller river within the square and too small to be visible.

Summary

In my view the "river as barrier" and "don't conflict with other terrain" argument strongly favour the river on edge option.

The possible visual appeal of the in square option seems to me very minor, and is offset by the possiblity of obscuring other features.

I confess to being inluenced by:

"Crossing the Rubicon!"

"Crossing the Nemen!"

"Crossing the Berezina!"

"Crossing the Rhine!"

Cheers

[Mark_Everson]

I guess I'm flexible on the topic. I admit the road-river graphics collision hadn't occurred to me before you mentioned it, and that tips the scales back toward on-edge rivers some. So I suppose if a majority can be swayed to go that way It'd be fine by me to change and try it your way.

What do others think?

But, as a minor issue, I think that canals should be represented the same as rivers, since frequently the two attach to each other.

[Gary Thomas]

But, as a minor issue, I think that canals should be represented the same as rivers, since frequently the two attach to each other.

I have no problem with that. Bearing in mind that we are talking about Kiel, Panama or Suez level canals here, not the small local canal of England.

Suez Canal at least has significant barrier implications.

Cheers

[Gary Thomas]

I admit the road-river graphics collision hadn't occurred to me before you mentioned it, and that tips the scales back toward on-edge rivers some.

To me the barrier effect is quite a bit more important than the graphics consideration. I like the possibility of Remagen Bridgehead situations, which are impossible under the other system.

Cheers

[Lord God Jinnai]

While barrier is important, I think going with edge rivers looses several aspects.

1. Can't use rivers to travel quickly. Rivers were often used as perferred modes of transportation, espicially downstream, but with them on edges you couldn't do that. This is espically important as this is how Norsemen raided Europe easily.

2. Graphical reasons are important also. While they aren't the most important, having rivers that turn at right-angles is very hard at suspending disbelief. Not everyone will be playing war/strategy-intensive games.

3. Bridge effect can be done with rivers on center squares also. Without such technolgy, you just couldn't build a road on that square say.

4. The Border idea, which seems to be the strongest argument, will be hard to implimnet. Oftern countires were forced to stop a these 'natural boundries' such as rivers and mountain ranges. While using rivers for such a purpose is a good idea, the AI and coding required to put these into effect is probably nearly impossible.

[Gary Thomas]

1. Can't use rivers to travel quickly. Rivers were often used as perferred modes of transportation, espicially downstream, but with them on edges you couldn't do that. This is espically important as this is how Norsemen raided Europe easily.

I can't see how this follows. As long as the same river is in adjacent squares (whether in the centre or on the edge) the same coding for movement applies in both cases.

2. Graphical reasons are important also. While they aren't the most important, having rivers that turn at right-angles is very hard at suspending disbelief. Not everyone will be playing war/strategy-intensive games.

If suspension of disbelief is a problem we shouldn't be using squares - squares are actually just a hangover from board games. It is perfectly possible to have a terrain map which doesn't requires squares at all. Such a system has the best of all possible worlds - no matter where a river is it is easy to tell which side of the river a unit or city is. In such as system rivers can wind perfectly naturally, gorges are possible, and so forth. If we are going to suspend disbelief to the point where all turns are 45 degrees, we might as well accept right angles. In fact I have seen such maps and they don't look bad at all. The right-angle effect is much reduced if the rivers cut corners somewhat.

Also, as I stated earlier, rivers in the middle clash with lots of other graphical features which should be in the middle. Mainly roads and towns.

3. Bridge effect can be done with rivers on center squares also. Without such technolgy, you just couldn't build a road on that square say.

That is a bit extreme - no roads for 50 km, simply because you can't bridge the river? What about fords and ferries? Both of
these are easily accomodated in the rivers on edge system.

4. The Border idea, which seems to be the strongest argument, will be hard to implimnet. Oftern countires were forced to stop a these 'natural boundries' such as rivers and mountain ranges. While using rivers for such a purpose is a good idea, the AI and coding required to put these into effect is probably nearly impossible.

Why on earth should it be difficult? As far as coding is concerned I can see no problems at all.

Cheers