Stream vs Minor River

[GeoNL]

So, I am a little confused as to the definition of both. I am constructing a map that is based in the north part of the Netherlands (mostly in the North-West part of Drenthe). There are many, as they say in Dutch, "dieps" here. Which basically are "streams". However, the default movements effects for streams in the game are 10 for motorised and 30 for non-motorised. I am unsure if I should substitute some of these streams for light river or not. Since there is a situation up here where several streams run into a somekind of canal, which is closest to a light river I suppose. It's kinda awkward in gameplay to have bridges on that canal, and attached to a stream which makes the bridge useless in the end.

Some streams are small'ish, others are more broad.

1. Does this mean that any motorised vehicle is able to cross a stream with ease (even if much slower)?
2. I am unsure what's best, go for realism, or uplift streams to light river to make things a little less awkward? Trying to figure if , let's say the average Sherman tank was able to cross a "stream". And how fast.

 

[Bie]

So, I am a little confused as to the definition of both. I am constructing a map that is based in the north part of the Netherlands (mostly in the North-West part of Drenthe). There are many, as they say in Dutch, "dieps" here. Which basically are "streams". However, the default movements effects for streams in the game are 10 for motorised and 30 for non-motorised. I am unsure if I should substitute some of these streams for light river or not. Since there is a situation up here where several streams run into a somekind of canal, which is closest to a light river I suppose. It's kinda awkward in gameplay to have bridges on that canal, and attached to a stream which makes the bridge useless in the end.

Some streams are small'ish, others are more broad.

1. Does this mean that any motorised vehicle is able to cross a stream with ease (even if much slower)?
2. I am unsure what's best, go for realism, or uplift streams to light river to make things a little less awkward? Trying to figure if , let's say the average Sherman tank was able to cross a "stream". And how fast.

1. Yes, you don't need to put in bridges for motorized units to be able to cross streams or even minor rivers.
2. It depends on what you want to achieve. I only tend to use the major rivers (impassable without a bridge) if it is an actual really wide river/canal. If the seizing of a bridge was an actual historical objective and crucial for the continuation of the operation I tend to use major rivers and put in a bridge. If there are many small streams or ditches I tend to also use the "polder" layer to abstract those. You can still put in some streams on top of that layer for added visuals.

 

[GeoNL]

1. Yes, you don't need to put in bridges for motorized units to be able to cross streams or even minor rivers.
2. It depends on what you want to achieve. I only tend to use the major rivers (impassable without a bridge) if it is an actual really wide river/canal. If the seizing of a bridge was an actual historical objective and crucial for the continuation of the operation I tend to use major rivers and put in a bridge. If there are many small streams or ditches I tend to also use the "polder" layer to abstract those. You can still put in some streams on top of that layer for added visuals.

View attachment 7378

I see. Looking at your screenshot, I noticed you have streams near roads. As the manual says for rivers I need to create space for the roads near it, as to not accidently create a crossing. I assume for streams it does not matter.

Around the area I am creating (it is based on a map my father built around 2004-2005, which I am revamping from scratch), the biggest area of water is the Noord-Willemskanaal. Which is a very broad digged out canal, I have considered making this a major river. Since it has strategic value around key bridges across this canal (a railroad bridge and several smaller bridges, and a medium bridge crossing over the main highway through a small village called "De Punt"). Other than that, there are no real rivers. Just small & long streams. Where according to the maps of 1940 (I am using a map that was originally created for the Wehrmacht) there are also small bridges across several streams. So that's why it made me confused in that regard.

Also, I took a look at Arnhem and Nijmegen maps. They have the map effects in such a way that minor rivers are also not able to be crossed by motorised troops (0). Non-motorised is at (5).

The general idea is eventually also expanding the map north to include the city of Groningen (city of my birth) and the near vicinity. Historically the 2nd Canadian infantry division liberated the city in 1945 after several days of fierce fighting. Of course, the opposition was basically a rag-tag bunch of German SS, Wehrmacht and Luftwaffe units that were bundled together and were trying to retreat to Germany through the eastern parts of province of Groningen. So my scenario will be semi-fictional as to create a balanced scenario, one where the Canadians have the upperhand from the start is not very fun I think.

 

[Bie]

I see. Looking at your screenshot, I noticed you have streams near roads. As the manual says for rivers I need to create space for the roads near it, as to not accidently create a crossing. I assume for streams it does not matter.

You are right. You must understand that the game divides everything on the map in squares of a 100m x100m. You can see that if you use the pathing tool ingame/scenmaker. You will see minute red dots and a green line signifying the route the unit will take. The green line will always cling to those red dots.

So every unit will always go from dot to dot. Where this becomes important in creating your scenarios is that the different layers also are forced to follow these squares. Even though you can make very intricate terrain, the engine will abstract this and make them fit into the squares. You can also check that out by right clicking at the edges of layers. Sometimes a certain layer will not be actually there or the opposite, a layer might be there but visually it is not.

This becomes a problem if you are putting roads near impassable layers, like the major river. Try making a diagonally straight canal with roads immediately next to it. Half of the time the road will not be passable as the engine thinks there is a canal in the way. In the case of streams and minor rivers this is not really a problem as the road will be just "going over it".

Around the area I am creating (it is based on a map my father built around 2004-2005, which I am revamping from scratch), the biggest area of water is the Noord-Willemskanaal. Which is a very broad digged out canal, I have considered making this a major river. Since it has strategic value around key bridges across this canal (a railroad bridge and several smaller bridges, and a medium bridge crossing over the main highway through a small village called "De Punt"). Other than that, there are no real rivers. Just small & long streams. Where according to the maps of 1940 (I am using a map that was originally created for the Wehrmacht) there are also small bridges across several streams. So that's why it made me confused in that regard.

I've taken a look at the area on Google Maps and indeed the Noord-Willemskanaal should be considered as a major river with the necessary crossings.

Concerning the translation from original map to Co2 map: I have mostly used British GSGS maps for this. Knowing the Germans they would probably also have excellent maps, so that is not a problem. Keep in mind that you can really go nuts in putting in all this incredible detail, like putting bridges on minor rivers. But most of the time it does not really pay of.

My first maps were to detailed and I faithfully put a bridge on every crossing just as it said on the GSGS map. Now I see that it is not really necessary and it is isn't worth it.

 

[GeoNL]

You are right. You must understand that the game divides everything on the map in squares of a 100m x100m. You can see that if you use the pathing tool ingame/scenmaker. You will see minute red dots and a green line signifying the route the unit will take. The green line will always cling to those red dots.

So every unit will always go from dot to dot. Where this becomes important in creating your scenarios is that the different layers also are forced to follow these squares. Even though you can make very intricate terrain, the engine will abstract this and make them fit into the squares. You can also check that out by right clicking at the edges of layers. Sometimes a certain layer will not be actually there or the opposite, a layer might be there but visually it is not.

This becomes a problem if you are putting roads near impassable layers, like the major river. Try making a diagonally straight canal with roads immediately next to it. Half of the time the road will not be passable as the engine thinks there is a canal in the way. In the case of streams and minor rivers this is not really a problem as the road will be just "going over it".
.

Understood, thanks for the comprehensive explanation. Will take this into account from now on.

I've taken a look at the area on Google Maps and indeed the Noord-Willemskanaal should be considered as a major river with the necessary crossings.

Concerning the translation from original map to Co2 map: I have mostly used British GSGS maps for this. Knowing the Germans they would probably also have excellent maps, so that is not a problem. Keep in mind that you can really go nuts in putting in all this incredible detail, like putting bridges on minor rivers. But most of the time it does not really pay of.

My first maps were to detailed and I faithfully put a bridge on every crossing just as it said on the GSGS map. Now I see that it is not really necessary and it is isn't worth it.

I have a tendency to try and put in as much detail as possible. So I recognise what you mean. In that case, I will remove most bridges from streams. The map details also many tracks, dirt roads and such. I have faithfully added all of these. I assume it isn't a problem that in some areas there are quite a few tracks near eachother?

 

[Bie]

The map details also many tracks, dirt roads and such. I have faithfully added all of these. I assume it isn't a problem that in some areas there are quite a few tracks near eachother?

I also tend to put in a lot of roads, even a lot of the dirt tracks. There should not really be a problem if you put them close to each other.

 

[jimcarravallah]

So, I am a little confused as to the definition of both. I am constructing a map that is based in the north part of the Netherlands (mostly in the North-West part of Drenthe). There are many, as they say in Dutch, "dieps" here. Which basically are "streams". However, the default movements effects for streams in the game are 10 for motorised and 30 for non-motorised. I am unsure if I should substitute some of these streams for light river or not. Since there is a situation up here where several streams run into a somekind of canal, which is closest to a light river I suppose. It's kinda awkward in gameplay to have bridges on that canal, and attached to a stream which makes the bridge useless in the end.

Some streams are small'ish, others are more broad.

1. Does this mean that any motorised vehicle is able to cross a stream with ease (even if much slower)?
2. I am unsure what's best, go for realism, or uplift streams to light river to make things a little less awkward? Trying to figure if , let's say the average Sherman tank was able to cross a "stream". And how fast.

What you receive as the default terrain pallet is what was used to build the first commercial scenarios for the game engine. Those reflected combat in Market Garden and the regions that traversed.

If that pallet does not represent what you believe to be an accurate portrayal of the movement or visibility effects for terrain you're modeling, you can control the effects on movement and visibility assigned to the map layers (or terrain features defined on the pallet), and in fact, can change the terrain feature name ("stream" vs. "dieps") if you so choose. The data, as I best understand, is assigned to a specific map.

The manner to do this is explained on page 29 of the MapMaker manual.

Effects for terrain features (both area and line features, such as a stream) are based on a general analysis of the particular feature's ground cover and and width and depth measurements among that cover. In the case of a stream and movement, you're dealing with a rather narrow obstacle, which in general is shallow enough for a vehicle to traverse with a significant amount of difficulty (using the statistics you mention, at only 10-percent a normal road movement rate). If the particular stream you are portraying is too deep for even a 90-percent decrement in movement, then you can set the penalty even lower, or at zero, making the feature impassible.

The one thing you have to keep in mind is that the terrain pallet provides the maximum number of terrain features that can be portrayed (absent the height layers, which are limited to 15 steps). If you are going to have one form of stream which is passable at 10-percent of road movement, and another that is impassible, you should change the character (and ultimately the graphic) for a related feature (line or area) that you wouldn't be using anyway.

 

[john connor]

Very useful, Bie. I'd second what Jim says, too - you should feel free, GeoNL, to change the movement and cover characteristics for your layers. It's very easy to do. You can also change the 'height' for your layers, meaning the height of grass growing there, bushes etc - which affects LOS calculations. I have found that in order to truly limit ideal clear-weather daytime LOS (which you need to think of as highly abstracted as if computed over a 'front' representing the spread and different sighting positions of many units in an element) then you would need to limit LOS much more than is done in the default layer characteristics, though since your map is in a relatively flat part of the world, not filled with bocage or such like, you may not need to.

 

[GeoNL]

Very useful, Bie. I'd second what Jim says, too - you should feel free, GeoNL, to change the movement and cover characteristics for your layers. It's very easy to do. You can also change the 'height' for your layers, meaning the height of grass growing there, bushes etc - which affects LOS calculations. I have found that in order to truly limit ideal clear-weather daytime LOS (which you need to think of as highly abstracted as if computed over a 'front' representing the spread and different sighting positions of many units in an element) then you would need to limit LOS much more than is done in the default layer characteristics, though since your map is in a relatively flat part of the world, not filled with bocage or such like, you may not need to.

Yes, most is generally flat. One unique feature common in these parts, especially back in WW2 period are "houtwallen" literally translated "wood walls". If that is a thing in English. Imagine bocages, except these are lines of trees and/or bushes on slightly elevated ground, mostly on large open spaces of land against the wind and such. Other than that, the area (Drenthe area) was filled with lots of "heide" in open areas. Nowadays almost completely gone though.

 

[GeoNL]

This is the W.I.P. at the moment, for anyone interested what it's all about. If anyone sees anything wrong on first sight, feel free to tell me.

 

[Bie]

That is a great looking map. How big is it?

 

[GeoNL]

That is a great looking map. How big is it?

Thanks. It is 19000 x 15000 . The general idea is that this area is the "prelude" to the battle of Groningen. More or less. Most important place on this map so far is around Eelde, which has the airstrips which the Germans have used a lot for different air sorties (currently anno 2019 it is a modern airport). Everything leads upwards to the city, which is a vital strategic area because it leads to the eastern part of Groningen (province) directly to Delfzijl , which was considered an important harbour for both parties. Other than that, everything across the Noord-Willems Kanaal is vital, since the train tracks go across that area to Groningen.

 

[Dave 'Arjuna' O'Connor]

Re the map. Looks nice. It would be good to see this with grid lines so w can get an idea of how close together those roads are down in the bottom left corner for example. Remember, that laying down a road is like bulldozing flat a 100m wide area. So if you have a lot of roads close together it becomes in effect open ground and that may not be what you want.

 

[GeoNL]

Re the map. Looks nice. It would be good to see this with grid lines so w can get an idea of how close together those roads are down in the bottom left corner for example. Remember, that laying down a road is like bulldozing flat a 100m wide area. So if you have a lot of roads close together it becomes in effect open ground and that may not be what you want.

Alright, understood. Maybe some roads could be removed in that case. Here with grids (and with some new progress), the heights I am doing last by the way. I did a few heights here and there, but decided to do it in the end instead.

 

[ioncore]

Dave, they could use smaller table cells, like 50m or even 25m, and thus get higher terrain fidelity,couldn't they?

 

[Dave 'Arjuna' O'Connor]

Yes but that introduces other issues. I think a little pruning would suffice.

 

[GeoNL]

Thanks for the advice. At some point it crossed my mind I might have overdone the details concerning roads, mostly with tracks.

 

[jimcarravallah]

Dave, they could use smaller table cells, like 50m or even 25m, and thus get higher terrain fidelity,couldn't they?

I've worked with 25-meter grid, and note a lot more map detail as a result. However, it also leads to some slowing of the game as the grids' effects are measured against force movement and combat. I haven't got to the point of a crash, but would anticipate it if the map expanse was large enough and the grids small enough to overwhelm available RAM with terrain calculations.

 

[GeoNL]

I've worked with 25-meter grid, and note a lot more map detail as a result. However, it also leads to some slowing of the game as the grids' effects are measured against force movement and combat. I haven't got to the point of a crash, but would anticipate it if the map expanse was large enough and the grids small enough to overwhelm available RAM with terrain calculations.

I would like to try this out, just to test. How does one change the grid parameters?

 

[Bie]

You can do it in the mapmaker: go to map in the toolbar and select "Calculate Terrain Tables". There you can change the grid size from the standard 100 to anything you like.

My "Benouville - Ranville Bridges" map has a grid size of 25. For such a small and detailed scenario it had to be done. I've tried to do it with the full "Caen - Ouistreham" map, but due to the bigger scope of the scenario it quickly became to slow while running the game. So beware if you plan on using lots of units in your scenario. Smaller grid size means more calculations to be done when units are moving. Lots of moving units will generate lots of calculations. Put them both together and you've got slowdowns, so be wary and keep checking if it doesn't run to slow.