New in mapmaking : lot of questions here...

[Izidor44]

Hi Gentlemen,

I would like to share with us my last attempts in map making.

I consider myself as a complete newbie, in comparison with other map gurus (Blade2k5 or Dobdriver for example), so I would like to know your advices and comments about mapping techniques.

My arsenal :

- GIMP portable software
- SC4 Mapper
- SC4 Terraformer
- Microdem Software
- USGS – U.S. Geological Survey (http://www.usgs.gov/) for DEM datas
- A calculator for GPS distance, mine here : http://www.abe.msstate.edu/~fto/calculator/converte.html
- And SC4 of course 

Basic methodology :

- Pick up a 3 or 1 Arc DEM map in .dt1 format and note geographical coordinates
- Calculate the map dimensions in kilometers
- Open the .dt1 map in Microdem

Example 1 : a freshly opened .dt1 map :



- Still in Microdem, convert it in grayscale and magnify it by x8 (you obtain a big .bmp file, with dimensions usually around 5000 x 7000 pixels)

Example 2 : same map converted in greyscale values :



- Open this huge .bmp file in GIMP and resize it correctly (1 km = 64 px)

I assume that, at this stage, this map is accurate in its dimensions, but I would be curious to know your comments here !

Then, I zone the portion of the map which interests me, keeping in mind the correct dimensions fitting the SC4 standards (example : 2561 x 2561 pixels for a 40 x 40 km (10 x 10 big tiles) map ). And then comes the artistic sequence : softening the sea border, redraw rivers and correct some pixel oddities.

About rivers : usually, I don't redraw it because, as the global elevation level rise, the river progressively "dive" in the ground, creating very deep valleys, completely unrealistic. I guess it could be affordable to draw rivers when global elevation is always smooth and not too high from sea level.

The elevation nightmare :

The big problem for me now is referring to elevation : is this technique accurate and respectfull with real elevations ? I don't think so...

Let's see :

With a .dt1 map, converted in .bmp format, a 0 grey value means "water" and 1 grey value mean "lowest land". But 255 grey value means the maximum elevation, which could be anything from gentle hills to Himalayan peaks ! Then the real elevation shape of the map could be "smashed" as soon as the maximum elevation is higher than 514 meters (the highest elevation handled in SC4).

So, how can you recreate a simple mountain of 1.200 meters ? It's impossible ? 

During mapmaking, at this stage, I simply adjust the global lightness by +83 in order to transfom "1" grey value to "84" grey value (which is the lowest land in SC4).

Example 3 : final result (rotated) in SC4T



But my major difficulty is to adjust these elevations, I need some advices here. I would like to have my highest mountains still at +514 meters (maximum in SC4) and my lowest land at 1 meters. How can you do that without messing everything ?

By the way, is still don't have a fond to recreate bathymetric values, I wonder of a kind of GIMP filter can do the trick...

Anyway, comments are welcome ! 

[Lowkee33]

Hi Izidor,

The tutorial that worked for me is linked to in This post. (It's in German, but that is not an issue these days.)

I believe you loose a lot of data when you export it as a bmp.  From DEM maps it's best to use 16bit png.  However, GIMP can't handle this, and will convert the file back down to 8bit.  Not sure why you would scale up and then down, but surely this will loose data too.

You need terraformer to use the 16bit png, they can't be rendered in-game.  Import the greyscale, and if you end up with all water, increase the value on the "import" settings (I think 5000m worked for me).

You should end up with a real-life accurate map.