A Couple of Mapmaking Questions

[JonS]

OK I am a happy camper now. I watched this video: http://earth.google.com/support/bin/static.py?page=guide.cs&guide=22365&topic=23729

I'ver also done a polygon overlay in Google earth for the map I'm working on.

One trick I found, was once you've done one polygon, you can copy-paste it and then you just need to edit the elevation. They end up exactly the same size, and in exactly the same place.

I also found it helpful to re-name each layer to the height it represents.

[A Canadian Cat]

I'ver also done a polygon overlay in Google earth for the map I'm working on.

One trick I found, was once you've done one polygon, you can copy-paste it and the you just need to edit the elevation. They end up exactly the same size, and in exactly the same place.

I also found it helpful to re-name each layer to the height it represents.

Excellent tip. My test map was looking a bit ragged with all my mismatched polygons...

[mjkerner]

I had the same problem as Ian, but I fiddled all day yesterday and finally figured it out. You'd think Google with all its cash and staff could come up with a more intuitive program but still, once its working, the polygon/elevation system is pretty cool. I now have my topo, gridded map in 8m x 8m squares ready for the map editor.

My thanks to Broadsword56, Ian, JonS and DaveyJJfor your help and inspiration.

P.S. Does anyone know if there is any way to auto-number the squares in Paintshop Pro? Not a big deal--I'l just number down one side and letter across the top, and do the old SL/ASL routine.

[Broadsword56]

Does anyone know if there is any way to auto-number the squares in Paintshop Pro? Not a big deal--I'l just number down one side and letter across the top, and do the old SL/ASL routine.

No, but -- just curious -- why would you need to do that if you can see the x/y coordinates of each square? To locate any point, just match the coordinates of a particular grid square to the corresponding x/y coordinates of a map tile in the CMBN editor.

(The only catch is, I don't know yet how the CMBN editor will number the y axis. My Gimp graphics program numbers the y from top to bottom, but some games' map editors -- like the Theatre of War series -- have used a system where 0,0 is the center of the map and everything is numbered + or - depending on which quadrant it's in. That would be a big problem.)

[winkelried]

Does anybody know what data set google uses for the elevation? I did a stretch of map where I have the (modern, offical) 1:25k and 1:50k data and there seems to be quite some devations to those produced by google. Same holds for radar data.

[Broadsword56]

I don't know, but that's more precision than I'm going to worry about. If I can just get the basic "lay of the land" that allows the same historical tactical situation that existed on that terrain, then I won't worry about a few meters' difference here or there.

[winkelried]

few meters' difference here or there.

I fully understand, but in the particular case the differences are up to 500 meters and in google i completely miss an important terrain feature, the small trench running S-N in the middle of the pictures. You see it on the 1:50k and on the radar, but google misses out completely.

You'll still need several data sources it presume.

The strong red line in the middle is the 110m level.

[Comandante]

You'll need to wait for another module for that. Playing Tigers against Shermans in the game you cannot underestimate the role sheer luck played for Wittman... while his luck lasted. After all, it was a Sherman that eventually killed him.

IIRC, he was killed by a Sherman (Canadian?) and one or two of the accompanying Tigers were destroyed by Typhoons.

There were British anti-tank guns engaged as well. It was a real charge of the light brigade affair, I believe.

[DaveyJJ]

IIRC, he was killed by a Sherman (Canadian?) and one or two of the accompanying Tigers were destroyed by Typhoons.

There were British anti-tank guns engaged as well. It was a real charge of the light brigade affair, I believe.

Actually, the Typhoon hits have been discredited in a recent, very well done documentary about his last engagement.

The lead Tigers were hit (from their two o'clock positions) by British armour who were hidden on a small treed hillock overlooking the field they were travelling across at 700+ metre range, while Wittman's tank was hit in the left rear by a Canadian tank from a short range of about 150 yards. The wall the Canuck shot from still stands, as the farmer who owns the land was a kid at the time and has collected many parts from his tank, including Wittman's neck head microphone and many pieces of the turret.

http://www.history.ca/ontv/titledetails.aspx?titleid=116485

Preview here ...

Recommended viewing.

[Broadsword56]

Actually, the Typhoon hits have been discredited in a recent, very well done documentary about his last engagement.

The lead Tigers were hit

Hey guys - this is a mapmaking thread. I don't know where this Typhoon-Tiger discussion popped in from, but please take it elsewhere or make a new thread for it.

The information on this thread is really important for mappers, and we're really struggling to keep all the relevant information and links together so we don't have it spread all over the forum.

[mjkerner]

Broadsword, now I'm confused...a normal occurence, btw.

"To locate any point, just match the coordinates of a particular grid square to the corresponding x/y coordinates of a map tile in the CMBN editor."

But how can I do that if I don't know the coordinates of my Paintshop grid map? I can number them manually across and down, which I will do if necessary, but that's still a pain if I have to type text in 100 or more squares. There must be an easier way...

[Broadsword56]

It's been a while since I used Paintshop Pro, but doesn't it show a little data readout somewhere at the bottom of the screen that changes wherever you put your cursor, to show the x/y coordinates of the pixel? Have you checked your view options to see if something needs to be enabled?

Just FYI, I now use Gimp, which is also a free program and (IMHO) superior for mapping than Paintshop Pro. On the cartography enthusiast sites I've visited like The Cartographer's Guild, most seem to be using either Photoshop or Gimp.

[TheVulture]

I've just finished (well, nearly) a small utility for creating grid overlays for google earth if anyone is interested. yeah - some already exist, but I just wanted a small, CM dedicated app that allowed me to create grids rotated relative to the North/East directions. (I want to create a map of an area that just happens to live quite tidily on a grid layout rotated about 25 degrees from north, so being able to overlay a grid at an arbitrary angle seemed a useful tool).

Anyway, you specify the center (lontigude / latitude - too lazy to right a UTM easting / northing converter too), x and y size of the grid, spacing (8 meters seems an obvious choice) and rotation away from north. It generates a grid with the given spacing and heavier lines every 200 meters and it generates a grid overlay .kml file that google earth can load.

Anyone else think this might be useful?

[DaveyJJ]

I've just finished (well, nearly) a small utility for creating grid overlays for google earth if anyone is interested. yeah - some already exist, but I just wanted a small, CM dedicated app that allowed me to create grids rotated relative to the North/East directions. (I want to create a map of an area that just happens to live quite tidily on a grid layout rotated about 25 degrees from north, so being able to overlay a grid at an arbitrary angle seemed a useful tool).

Anyway, you specify the center (lontigude / latitude - too lazy to right a UTM easting / northing converter too), x and y size of the grid, spacing (8 meters seems an obvious choice) and rotation away from north. It generates a grid with the given spacing and heavier lines every 200 meters and it generates a grid overlay .kml file that google earth can load.

Anyone else think this might be useful?

Yes, please.

[mjkerner]

@Broadsword...no doubt there is, it took me aloooong time to get good at Paint Shop, so I probably missed that. Thanks.

@the Vulture...you bet!

[C'Rogers]

I don't want to sidetrack the thread, but did want to answer a question from the OP that I don't think ever got addressed.

The vertical scale is set at 1m because larger than that would be too intense of a drain on the system. Individual height raises though are tracked to the millimeter (if you were to do a 1m raise across an entire map as people pointed out).

I think, but could be wrong as couldn't find a source, that is a similar reason for the 4x4 km map cap.

[Broadsword56]

The vertical scale is set at 1m because larger than that would be too intense of a drain on the system. Individual height raises though are tracked to the millimeter (if you were to do a 1m raise across an entire map as people pointed out).

Can you explain what vertical scale is? I don't quite understand it. What effect does it have on the map and what limits does it put on the map designer?

[Magpie_Oz]

Can you explain what vertical scale is? I don't quite understand it. What effect does it have on the map and what limits does it put on the map designer?

I think it means the smallest change in height you can map is 1m. So if you have a 0.5m high bank, it would need to be modelled as 1m or 0m

[JonS]

Last night I finished the road net, added spot heights where they were indicated by Geoportail, then commenced the contour lines. The Geoprtail contours are at 5m intervals. I started with the 200 and 225m contours over the whole map, then completed all the contours for 10 of my 500x500 squares. I used 5m increments, and added a 'blackspot' every other square. I had to go back and do some detailed adjustment in some places, especially where a stream runs down a narrow steep valley, and along a major, 16m wide, highway to make sure it stayed flat and to raise a section that crosses a low valley. The highway is looking pretty good, with cuttings and embankments that look quite natural. There's also a nice (non-functional) culvert I've created where it crosses a steam.

That was about 2-2.5 hrs effort.

Tonight I'm aiming to finish the contours.

[A Canadian Cat]

<snip>I used 5m increments, and added a 'blackspot' every other square. <snip>

I'm curious by 'blackspot' are you referring to the dark colour the map editor uses to show a tile you have set the height for? If so why every other square?

<snip>The highway is looking pretty good, with cuttings and embankments that look quite natural. There's also a nice (non-functional) culvert I've created where it crosses a steam.

<snip>

Cool, can you share how you made a culvert?

Please,

Ian

[JonS]

I'm curious by 'blackspot' are you referring to the dark colour the map editor uses to show a tile you have set the height for? If so why every other square?

It seemed like a good compromise. I find that doing every square makes the map look to rigid, while large gaps between black spots leads to some fuinny results, especially where the terrain is steep.

I'll probably go back and delete some where the terrain is gentler, but at the moment it looks good.

Cool, can you share how you made a culvert?

Sure.

W = water

g = grass

# = cobblestones

gggggg

gg##gg

WWW#gg

gg##gg

gggggg

Basically, the stream runs up into a 'U' of cobblestones, then ends. On the other side of the road the reverse is built, the stream emerges from the 'U' and carries on.

Jon

[JonS]

FWIW; Contours completed last night. About 1.5-2 hrs. Next up are the buildings, villages, and hamlets, though that's going to take a few days as free time becomes scare over the next few days.

[JonS]

I've changed the plan. Rather than doing all the buildings then all of something else, I'm now completing chunks of ground that are bounded by roads and/or rail and/or river. Within each chunk I'm doing the fences/bocage roughly, then in detail, then any openings, then buildings, then adding foliage, and fine detail like added scrub, bushes and trees to the bocage lines, adjusting the ground type in the fields (adding crops, ploughs, etc). Finally I'm going in to the 3D editor and modifying the building facades, and checking that the lie of the land - especially the elevation/slope - makes sense around the buildings. I've pretty much ceased using the Geoportail map now, and am relying on the 1947 aerial photo, both printed and zoomed in on-screen.

I'm not touching flavour objects yet. Those will come last, and will probably be quite sparing.

In aggregate I've done about two (2) of my 500x500 squares. Each would take ~3-4 hours, although I'm being a bit more scatter-gunned than that. I've done the fairly small chunks in each of the four corners, and am now working my way along one edge. With the hedgerows now creeping actross the map, the lay of the land is much easier to observe - it's sort of like the old CMBO gridded-grass mod. The maximum elevation is 246m, while the minimum is 185m, and given the size of the map that doesn't lead to very pronounced changes of elevation, so without the fences and things on top it's quite hard for me to perceive the shape of the ground when it is just grass.

Incremental screen-grabs proceed apace.

Jon

[Magpie_Oz]

A question I did ask once before I think but is there a way to actually write the file itself, I mean is a map file a matrix of terrain values of something like that?

I am asking as I do a lot of vector mapping and it would be a snap to do heaps of maps really quickly if there was a way to convert my vector maps into Combat Mission Maps.

[Broadsword56]

Good question, Magpie -- I also wondered that, or if there might ever be any way to import things like DEM data, or even grayscale JPEG heightmaps, into the map editor to speed up the terrain creation process.