Battleaxe/Brevity Map

[Prince of Eckmühl]

So, I thought that I'd take a whack at this.

Beneath this text will be a 45k x 30K map of the area where the Battleaxe and Brevity battles were fought.

The map underlay was created from a Google earth satellite image. I also generated images for the terrain and roads for the same area, but the satellite image provides better nuance, something that's largely absent the other two formats.

Please, take a look at the JPG that I post and tell me if I'm totally off-base by proceeding in this manner. [:)]

Thanks,

PoE (aka ivanmoe)

[Arjuna]

Looks pretty good. Please let me know how you get on and if you need any advice, just ask here.

[Prince of Eckmühl]

ORIGINAL: Arjuna

Looks pretty good. Please let me know how you get on and if you need any advice, just ask here.

Okay, I've got a philosophical dilemma regarding a JPG that I'll embed in this post...

The image is another Google maps capture, one which displays elevation. The contour lines in the image are in increments of 20m. As you'll see when you examine the image, the elevation in places goes from 40m to 180m in about half of a kilometer. The good news is that the maximum terrain elevation in the map appears to be 200m.

I had planned on using 20m elevation increments so that my map would correspond to the Google terrain contours. However, If I do so, eighty-percent of the contour lines are gonna be packed inside an area about the width of a 1-kilometer grid box. Would you suggest that I increase the contour to a greater value, 40m perhaps?

[Arjuna]

yes there are only 15 elevation layers in the current map structure. so you need to set your interval so that you can cover the full range from lowest to highest - ie interval = ( highest - lowest ) / 15

[Prince of Eckmühl]

Good deal; appreciate your reply.

Question:

The guide indicates that Control Points require more memory and disk space than Corner Points.

This implies that I should try to limit the extent to which I employ Control Points.

Is that the case?

[Prince of Eckmühl]

More questions:

What's the difference between "beach" as a terrain, and the area where a level 0 altitude layer interfaces with lake terrain?

Second, is more of an issue than a question...

I find myself having trouble "closing" altitude layers. Sometimes, they close on their own (as they are supposed to do, I believe), while other times the polygon doesn't close and my work has to remedied via the UNDO command (or perhaps a reload of the file to/from a more desirable state). Any idea what it is that I'm doing wrong? I'm using CONTROL POINTS when this occurs, BTW

[Arjuna]

re beach terrain and level 0 terrain. The values for a terrain layer can be interroageted and set by double-clicking on the layer in the layer palette. This brings up a dialog with the values. There is no specific entry in the layer palette for the 0 layer ( perhaps we should put a dummy in for it ), however, its values are accessed from the Map\MapEffects menu where you can edit the default move effects. In theory there is nothing different between a beach and a change in elevation. However, by having a specific beach terrain you could provide additional movement and hit effects to reflect the effects of sand.

[Arjuna]

re contours. on some maps where the contours are intricate, it can be difficult to trace these correctly. The eye can be deceived and you jump a level and end up crossing over yourself. Try zooming in and following the contours carefully. Sometimes if you get completely messed up, the best idea is the kill off that set of points and start again.
 
 
re control and corner points. With most machines now having 2GB or more of RAM to run the game in, this is noi longer as important as it used to be.

[Prince of Eckmühl]

ORIGINAL: Arjuna

re beach terrain and level 0 terrain. The values for a terrain layer can be interroageted and set by double-clicking on the layer in the layer palette. This brings up a dialog with the values. There is no specific entry in the layer palette for the 0 layer ( perhaps we should put a dummy in for it ), however, its values are accessed from the Map\MapEffects menu where you can edit the default move effects. In theory there is nothing different between a beach and a change in elevation. However, by having a specific beach terrain you could provide additional movement and hit effects to reflect the effects of sand.

Okay, I've got you on the beach now. It "special" so that it can be modified so that it's attributes can be altered.

BTW, the level 0 altitude layer threw me a bit, at least until I turned the underlay off and saw that it was there. I suspect that others might find this confusing as well.

I'm somewhat concerned that I'm leaving gaps between altitude layers, little "skinny" ones, virtually imperceptible to the eye. Is there a mechanism in the editor to check for these?

[Prince of Eckmühl]

ORIGINAL: Arjuna

re contours. on some maps where the contours are intricate, it can be difficult to trace these correctly. The eye can be deceived and you jump a level and end up crossing over yourself. Try zooming in and following the contours carefully. Sometimes if you get completely messed up, the best idea is the kill off that set of points and start again.

This is really difficult on that escarpment, even on full zoom. The contours are packed very tightly together, and the rise in elevation very abrupt. Even using the control points, the contours have an angular quality that doesn't look right. And you are correct, when in doubt, start over!

re control and corner points. With most machines now having 2GB or more of RAM to run the game in, this is noi longer as important as it used to be.

I'm doing this on a WinXP machine that's maxed-out, memory capacity wise. I'm not seeing any performance issues with the editor, excepting the problem that I noted, being unable, sometimes, to get a polygon to close properly. Thoughts?

[Prince of Eckmühl]

BTW, I found a map that may have me feeling a touch of "Google Maps Remorse:"

http://www.lib.utexas.edu/maps/ams/nort ... nh35-1.jpg

In looking at this new map, some altitudes are depicted as going from 20 to 100m, skipping increments. I assume that these are cliffs. Would doing something similar with my altitude layers cause problems with the game when it does its calculations?

[Arjuna]

In some of the Greece maps we did for COTA we used one of the layers for cliff terrain and made this impassable. We did this because we only have the fifteen alt layers to play with and most of the action was down at the lower altitudes, because above the snow line was too cold for military forces to operate. For the main escarpment in Cyrenacia, you might like to do likewise. Then you can just say this area is effectively impassable.
 
I'm unsure as to exactly what you mean by gaps in the layers. When you Calc the Terrain using the menu item under the Map menu, it will convert the alt layer data to spot heights. So don't be too perturbed. All you are doing with the alt layers is saying that this area is at X height. The CalcTerrainData function then finds the adjacent layers and graduates the spot heights between these.
 
Re control points. Just try it and see.

[Prince of Eckmühl]

ORIGINAL: Arjuna
I'm unsure as to exactly what you mean by gaps in the layers.

A hard to detect seam sometimes appears between altitude layers.

For example, a 100m layer is drawn adjacent to a 80m layer, but a narrow band remains where one doesn't overlap the other.

Does that seam represent terrain that's 0m in altitude (or some other value)?

[Prince of Eckmühl]

ORIGINAL: Prince of Eckmühl

ORIGINAL: Arjuna
I'm unsure as to exactly what you mean by gaps in the layers.

A hard to detect seam sometimes appears between altitude layers.

For example, a 100m layer is drawn adjacent to a 80m layer, but a narrow band remains where one doesn't overlap the other.

Does that seam represent terrain that's 0m in altitude (or some other value)?

You there Dave? [;)]

Seriously, though, I think I may be in trouble.

When viewing my altitude layers at 2, 4 or 8 pixels per meter it looks perfect.

However, at 16 the "seams" that I make reference to above begin to appear between some of the map countours.

They are somewhat worse at 32, and even more so at 64.

I've attempted to edit the contours to fill in any gaps that may be causing this, but I don't think that its working.

Is it time to start over?

The map with about 50% of the altitude layers completed (note the speckles):

[Arjuna]

Are you composing each layer with one or several ploygons - ie a series of points connected to each other?

[Prince of Eckmühl]

The 100m layer is made up of three segments.

Being somewhat unfamiliar with the interface, I did it that way to avoid losing my work if (when) I messed up.

With the exception of a few, isolated, "altitude islands," the rest are all single polygons, albeit 45k long in some instances.

I can nuke all three of those segments if necessary, and simply redo the 100m layer.

That'd beat the heck out of starting over.

BTW, being faithful to my underlay map will require additional altitude islands, but it doesn't appear that isolated layers are the problem.

Question:

Will creating a large altitude island, say 200m, and then drawing a 220m island in the middle of it, be a problem?

[Arjuna]

Effectively the altitide layers should be stacked one on top of the other like a pyramid, with the lowest alt layer on the bottom and the highest on top. Of course you may need to sanke the polygon around quite a bit, but there should be no islands per se - ie you should not end up with a lower alt layer in the middle of a higher one.

[Prince of Eckmühl]

ORIGINAL: Arjuna

Effectively the altitide layers should be stacked one on top of the other like a pyramid, with the lowest alt layer on the bottom and the highest on top.

Ah, like a layer cake? [;)]

Of course you may need to sanke the polygon around quite a bit, but there should be no islands per se - ie you should not end up with a lower alt layer in the middle of a higher one.

So, I trace the 20m layer, and then stack the others, one after another on top?

I misunderstood the process to the extent that I thought that I could place any altitude layer on any altitude 0 area so long as the former was properly coded.

I don't want to belabor the point, but do I have to draw in ALL of the lower altitude layers before I can draw a higher one?

For example, Do I have to draw a 20m layer over the top of the entire (non-0) map before I draw any 40m areas?

It doesn't really matter, excepting I'll have to plan very carefully ahead of time.

There are a lot of inland basins on the map I'm working with, and they'll tend to go unnoticed until the higher layers are already done.

Thanks for sticking with me on this one!

[Prince of Eckmühl]

And while I've got your attention...[:D] [:)]

I need a minefield terrain-object to place around Halfaya Pass.

Any thoughts about terrain effects parameters that I might use?

[Arjuna]

You can draw the alt layers in any order you like. I would recommend from the bottom up , but some do it from the top down. It doesn't matter, so long as a higher layer doesn't extend over the edge of a lower layer. They can almost abut like at an escarpment or cliff.
 
Re minefields. Warning. We do not have any mine clearing capabilities in the engine yet. However, feel free to create a minefield layer and make its movement effect pretty low but not impassable, to reflect the time that would be spent clearing lanes to get through. Refer to other terrain like swamps for an example - though don't make it impassable to motorised.