Map scaling
#1

I have a map making beginners question. I am confused about scale and how to do it. If I make Mymap_c.tga at pixel=100m, would map_h still be pixel=200m or 400m [1/4 as per the tutorial]. Etc.

I guess I am looking for a more comprehensive discussion/instruction on reduced scale mapping. Pros/Cons, How to etc.

I have read the Tutorial in tools and produced a successful full scale map of Nauru but I can not find any discussion on reduced scaling large area maps [multiple DEMS]. Could one of the map masters instruct this grasshopper or point me in the right direction to any existing tutorials/discussions on scale?


Thanks in advance .... and sorry for such a rudimental question.

~S~
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#2

The relation of the map_c to the other map files is always the same (4/1), no matter what scale your are using.
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#3

When you make a DEM in microdem and apply the map area command (set map pixel size), it's usually recommended to choose 50, which is said to mean that 1 pixel = 50meters of real world terrain. That is apparently what Il-2 considers to be 1/1 scale.

So, if you should choose a higher number to alter your map pixel size, say 100, then this should mean that you are working on 1/2 scale, while if you were to use 25, then it would be 2/1 scale ...

1/1 scale looks best usually, but if you're having memory problems with Microdem, you can also fudge around and use 55 or 60 without it being too apparent. Higher than that though and mountainous terrain starts to look rather unrealistic ... but if the terrain is mostly flat or rolling country/hills, then it doesn't matter very much since deformations won't be very noticeable.

I can't say anything about using larger scales, say map pixel sizes lower than 50. I tend to try and make maps as large as possible and i usually have to make an effort to stay at 50 without getting insufficient memory messages in Microdem.
__________________

I don't know if the following is also what you asked, but it never hurts to keep these map sizes in mind when map making:

100% maps : my_mapc.tga (which is Il-2 formatted into map_c)
50% maps : ed_m01.tga
25% maps : ed_m02.tga / map_h.tga / map_t.tga / map_f.tga / ed_map_t.tga (if used)
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#4

This helps a lot . . . . looks like I need a bigger computer! I am building the Azores so I will try 55. I got a 'out of resources' message at 50.
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#5

Yorktown Wrote:This helps a lot . . . . looks like I need a bigger computer! I am building the Azores so I will try 55. I got a 'out of resources' message at 50.

With islands, it can sometimes be a solution to make the map in several parts and then to recombine the parts together afterwards. This because of the large distances between the islands, which makes for often huge sized DEMs but with little land mass in them. I did that with the Aleutians map and while you need to be careful with recombining the parts, it helps with the DEM ...

You only need 2 basic images from the DEM anyway, a gray and a color bmp ... you should be able to pull off making both pixel perfect from each 2 smaller color/gray bmp's ...

And if you really want to go basic, you only need the gray bmp image to make a map ... the color bmps are not really necessary if you make your ed_m01 maps from other more colorful and better looking sources, say a googles map overlay site such as this one:

http://www.maps-for-free.com/
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#6

agracier Wrote:And if you really want to go basic, you only need the gray bmp image to make a map ... the color bmps are not really necessary if you make your ed_m01 maps from other more colorful and better looking sources, say a googles map overlay site such as this one:

http://www.maps-for-free.com/

Oh my! Isn't that useful! Hadn't seen it before.
:cheers:
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#7

Interresting.

does this mean that it's possible to rescale a map, an existing one?
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#8

redko Wrote:Interresting.

does this mean that it's possible to rescale a map, an existing one?

Don't see why not, although there would be problems. Map_c would be either too blurred or not blurred enough, and map_t would need completely remaking. Also, the actors.static would be a complete load of garbage, and you'd have to redo all of the names. In fact, I don't think it would be worth bothering - you'd be better off starting from scratch.

:cheers:
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#9

redko Wrote:Interresting.
does this mean that it's possible to rescale a map, an existing one?

If an existing map is finished in all aspects, it would probably be hard to use an existing actors.static file anymore ... there might be ways around it, but I haven't even tried to see how that would work.

But if you'd rescale a map, or combine two existing maps into one, that should probably be not so difficult to do. It would take careful pixel perfect placement and alignment, but should be possible ... I've combined 2 DEM images into one map and that works fine ... as long as you can get a good gray DEM for the height map, all other maps can be made from that one ... though a color DEM helps a lot in finding height zones and aligning FMB overlay maps and all ...

However i don't know what would happen to map_h if it were made larger - would rescaling affect the gray scale of RGB values? And if you were to rescale map_T, then certainly all RGB values would become skewed and probably all messed up and unusable ...
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