Making Accurate-Scale Real-World Maps

[MallowTheCloud 41]

Hi everyone!

I am creating a new map-making tutorial, as the old one is not very close to the method I currently use to make maps.

This is going to be quite a long tutorial with a lot of information, so I am going to have to split it up in to sections. I'll edit this first post with each new section. Also, I will give two sets of information. The first will be the basics we will need to make an accurate-scale map.

Then, in quotes, I will give more in-depth information... as to why you're doing something, for example.quote>

Contents...

Preface 1: Downloading and Installing Necessary Programs

Preface 2: Setting up Global Mapper

Section 1: Finding and Downloading Correct Elevation Data

Section 2: Creating the Base Map

Section 3: Creating and Overlaying the First Water Template

Section 4: Creating and Overlaying the Second Water Template (optional)

Section 5: Cropping and Saving the Completed Greyscale JPG

Section 6: Rendering the Map

Preface 1: Downloading and Installing Necessary Programs

Before making any maps, we must get the programs that will allow us to make them. I have completed an exhaustive list of all the programs I use when making a to-scale map. They are as follows:

The Gimp

Global Mapper

High Elevation Import Mods W Erosion Control Parameters

iDraw

IrfanView

Landscape Designer

NASA World Wind

MS Paint

And of course, Sim City 4

* The Gimp will be used to select the water outlines for the First Water Template.

* Global Mapper will be used to make greyscale images from elevation data.

* The High Elevation Import Mods W Erosion Control Parameters will be used to more accurately portray elevations.

* iDraw will be used to create gradients, and to draw in water for the Second Water Template.

* IrfanView will be used to resize images, crop images, and change images to greyscale.

* Landscape Designer will be used to create custom config.bmp files.

* NASA World Wind will be used to get visual information from which we can create a Second Water Template. It will also be used to find coordinates of a city.

* MS Paint will be used to overlay the water template(s) on the greyscale elevation map.

* Sim City 4 will be used to render the final image, and play!

quote>

Another very important piece of information is the site from which we will get ALL of our elevation data:

NASA Elevation Data

In fact, there is some data we should download now for future reference. Go to the link above, then click on the "SRTM30" link. In every folder, there is a DEM file. Download each one to an empty folder which we will use for mapping information. It might be good to have a folder inside this Mapping folder specifically for this data. For example, you might put all the DEM files in

\Desktop\Mapping\Large Scale DEMS\

These are large scale DEMS that we can use as a filler for possible holes in the smaller scale elevation data. They're named for the top-leftmost coordinates, so, for example, the one containing Hawai'i is W180N40. They are split in to rectangles with a width of 40° longitude and a height of 50° latitude. For more information, go here.quote>

Next, we will set up Global Mapper for easy use with SC4.

Preface 2: Setting up Global Mapper

There are many things we have to do in order to get Global Mapper to be easy to use. Once we do this, though, the options will not have to be changed again.

First, we want to remove the scale bars and change the scale to metric. To do that, go to the Tools menu, and down to Configure... Then, in the General tab, change the information to where it looks like the image below:

The scale displays will just take away much-needed area for the map, and we need the metric units so we can resize the map image properly.quote>

Next, we want to go to the Vertical Options tab and do a few things. First, uncheck the "Enable Hill Shading" tab. Then, change the "Elevation Display Units" to Metric. Next, make sure "Water Transparency" is 255 (Opaque). Finally, we want to click on "Water Color" to change it. In the color pallette, click "Define Custom Colors >>" and change the Red, Green, and Blue fields to 5 (see image below):

We need the water color to be as close to black as possible while still being differentiable by eye. In this way, we will be able to see the difference between the water outlines (which show up black) and the "water" that loads improperly. Furthermore, if this color was lighter, we might get it confused with actual land in the case that we were using a high import plugin, such as 5000m, because the lowest elevation of this plugin is a grey of 13.quote>

Next, we want the Shader Options tab. We have a lot of work to do here. First, under "Custom Shaders", click the New... button. Under "Name", type in 100. Then, click "Add" under "New Elevation" ("Height" should be 0). Now, click "Define Custom Colors >>" again, and set Red, Green, and Blue to 184. Then, click OK. Next, type in "100" for the height and click the "Add" button again. This time, set it to white (the bottom right color). Click OK to get out of the color selection, and make sure your Custom Shader screen looks like the one below:

Now, you think that was a lot of work? Well, we need to repeat this many times, once for each elevation mod. So, do everything the same, except name the new Custom Shaders for the max elevation, make the max elevation white, and base the grey for sea level (Height 0) on the following table:

100 - 184

250 - 129

500 - 87

1000 - 52

1500 - 38

2000 - 30

2500 - 25

3000 - 20

3500 - 17

4000 - 16

4500 - 14

5000 - 13

This is the feature of Global Mapper that, in my opinion, makes it better than other DEM loading utilities. Setting the correct elevations for each import mod now will save us loads of time when making the maps, and best of all, the elevation data will now be accurate. The Sea Level of the 100, 250, 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, and 5000 meter import mods are actually 182, 127, 85, 50, 36, 28, 23, 19, 16, 15, 13, and 12 respectively, but if you set them that low, especially with erosion upon rendering, there will be patches of water on what should be land.quote>

Finally, after all that, there's only one thing left to do. Click OK until you're back at the main screen, go to the View menu, go to "Background Color...", click "Define Custom Colors >>", and change Red, Green, and Blue to 5 so it looks like the image below:

We do this for the same reason we set the "water color" to RGBs of 5 each. This will show "missing" data, which we can't do anything about. In almost all cases, with the addition of a larger scale underlay, we can avoid missing data. The few places where this may not be the case is near the coast, so in the future when we change these dark areas, we will simply change them to sea level.quote>

Click OK, and we're done setting up Global Mapper!

Section 1: Finding and Downloading Correct Elevation Data

The first thing we need to do is to choose a location. It's pretty easy to just choose a city and work from there. We'll do San Diego for this example.

First, we will open NASA World Wind, hit CTRL+F, and search for San Diego. The first one is California, which is the one we'll do. Double click on it, and it will turn the globe to where you're hovering above San Diego. If you have text in the upper right, good. If you don't, hit F10. Now, you should have something like this:

Don't worry about anything except the "Latitude" and "Longitude"... but you will want to take down those numbers. So, in a temporary textpad, type something like:

Lat: 32.71520°

Lon: -117.15614°

You can close NASA World Wind for now. Examine the latitude and longitude. The first thing you'll want to note is how close each one is to the nearest whole number. For example, the latitude above, 32.71520°, is 0.28480° from 33.0°, and the longitude is 0.15614° from -117.0°. If either of these are within 0.2° away (in this example, the longitude is), we're going to need to download an additional piece of data.

We are going to want to download data that covers the latitudes from 32° to 33°, and longitudes from -117° to -118°, and ALSO from -116° to -117° (because the longitude was within 0.2° of the previous whole number). If the number is negative, we'll choose the higher end, and if it's positive the lower end. So, we want a latitude of 32° (the lower end) and longitudes of 118° and 117° (the higher ends). Positive latitudes are north, negative are south, positive longitudes are east, and negative are west.

So we finally have 32°N, 118°W, and 117°W.

The NASA Elevation Data website has files split in to sections that are 1° in longitude wide, and 1° in latitude high. They are named for the latitude and longitude in the lower left corner. So, some examples of places and their corresponding tiles would be as follows:

quote>

Next, we want to go to the NASA Elevation Data website and download the correct data. First, if the location is in the US, go to SRTM1, and if not, go to SRTM3. Since ours is San Diego, we'll go to SRTM1. Next (for US data only), click on the link at the bottom, called "Region definitions.jpg" Find what region your map is in (San Diego is in region 4), go back a page, and open the corresponding region folder. Now, we have a list of height files in the format N##W### (If you're elsewhere in the world, it might be N or S, E or W).

Note which latitudes and longitudes you want and hit CTRL+F. For San Diego, we will search for N32W117, and then N32W118 and download both of them. Below is an example in Firefox:

Download whichever ones you need... for San Diego, we will download both N32W117 and N32W118.

Now, we have the height files, but we need the water-boundary files. So, go back to the website, but this time, go to SWBD. If your longitude is east, go to SWBDeast, and if it's west, go to SWBDwest. For San Diego, it's west.

Now, do a CTRL+F again, but this time, the format is W###N## (If you're elsewhere in the world, it might be N or S, E or W), so search for it in that format. For San Diego, we will search for and download W117N32 and W118N32.

Now, find where you downloaded your zip files to, and unzip them to a special mapping folder. You have the correct elevation data! Don't close that temporary text pad yet, though! You know, the one with the latitude and longitude?

Section 2: Creating the Base Map

First, we need to load Global Mapper. The next step, though, depends on how many tiles of NASA data you had to download.

1 tile:

I will edit this information in later.

2 tiles:

In the case of San Diego, we had to download two tiles of data (32°N, 118°W and 32°N, 117°W). Hit CTRL+O to load the open dialog. Navigate to the folder you unzipped the files to, and select all the .hgt and the .shp files (holding down CTRL to select multiple files):

You'll get some dialog boxes regarding shape files and projection information... just hit OK through it all until your images load.

4 tiles:

I will edit this information in later.

The shp files are major water boundaries, such as boundaries for lakes, seas, or rivers. The hgt files are the elevation data. The shp files don't have built-in projection details, but they will be able to automatically choose the best projection information on their own.quote>

Next, use the top drop-down menu to select a color scheme, higher than the highest elevation in the terrain you will highlight. For San Diego, 1000 will likely do:

Try to judge which elevation scheme to use by finding the lowest one which has no white in the area you'll likely be zooming in on.quote>

The San Diego data is a bit tricky, because since I downloaded it from the US data (SRTM1), the data south of the border doesn't show up. But, anyway, use your latitude and longitude data to find the right spot to zoom in (for San Diego, it was Lat: 32.71520°, Lon: -117.15614° ). You'll notice in the bottom right of Global Mapper it shows the latitude and longitude of where your mouse is hovering over. Get as close to the right coordinates as possible, then click to zoom in. Click the near the top left twice more, and you should be on a pretty good zoom level. Hover the cursor over what looks like the highest point, and make sure it's below your currently selected color scheme. On my San Diego map, the highest point I can find is just over 250m, so I'll change my color scheme to 500m, the lowest I can go without parts of the map going over. Also, if you are using the "2 tile" method, check if there are any black splotches in high elevations (not just lake or river outlines, those are fine, but actual black splotches where there should be mountains aren't). If there are, you'll have to use a modified version of the "4 tile" method which I will explain later. For my San Diego map, there are no high-elevation black splotches, so I can continue.

You'll want to zoom in so that your region is about the right size... a good size is about 40 x 40 km or less, though if you want a bigger region, it is up to you. The larger your region, the less detail you will get using this method.quote>

To continue, view the map on Global Mapper, and hit the "Prt Scr" button on your keyboard. Without quitting Global Mapper, load IrfanView. Then paste the image in to IrfanView. Next, using your cursor, make a box around just the area that contains the map. Then, hit CTRL+Y to crop the image. Now, we have to figure out the scale.

Go back to Global Mapper (without closing IrfanView). Choose the tool at the top of the screen. Hold SHIFT and click the mouse once at the furthest left portion of the screen. Then, drag the ruler across the screen, keeping it as straight as possible, until you reach the right edge. Look in the bottom left corner to see how wide the map is (for San Diego, it's 24.5km). Type this in to your notepad to remember it. Next, do the same, only from the top to the bottom of the map rather than from right to left, and see how tall the map is (for San Diego, it's 21.1km). Type this in to your notepad as well.

Next, go back to the IrfanView image and hit CTRL+R to resize it. Make sure the "Preserve aspect ratio" box is unchecked, and the "Size method" is resize, not resample, and type in the new width and height using the following formula:

64 x km wide = pixels wide

64 x km high = pixels high

So, for San Diego, we have 64 x 24.5 = 1568 pixels wide, and 64 x 21.1 = 1350 pixels high:

Now, go to the Image menu, and down to "Convert to greyscale". Finally, save the image as a bmp file. You can name it whatever you want, but I'd suggest keeping the height mod number (color scheme in Global Mapper) in the title to remember. I named mine SanDiego500. Once you've saved the image, you have your base image! You can now close IrfanView, Global Mapper, and your temporary text file.

[cammo2003 20]

This needs to go into the Omnibus. Seriously.

[toxicpiano 125]

yes, this is very useful!

[MallowTheCloud 41]

I'm glad you find this useful! It's not nearly complete yet, but when it is, I'll look in to how to put it on the Omnibus.

[jplumbley 5]

Awesome tutorial partner!  I dont know if I am smart enough to remember all that but I think I will stick to my hand terraforming of fantasy land.

[moganite 4]

Awesome I was going to put up a tutorial about sizing sattelite images for a river/coastal template finny thing is I only use one template

[MallowTheCloud 41]

Thanks for the comments!

The first template will be from the water-boundary files from NASA... so it will already be the right size. The only problem is, it's not very detailed, so if you want very detailed rivers and lakes and such, you'll need to make another water template from a satellite image and resize it.

[Raxter 1]

Yeah, I noticed inaccuracies with water. Canals are completely overlooked, making a large portion of water bodies in Pennsylvania into land.

[Gh0sT_Pro 0]

Great tutorial, MallowTheCloud! Very easy to understand and follow. Only one thing worries me though ... no new posts for the last 6 months. Is there any chance we, mortal humans, can get the rest of it It would be a real shame such great piece of work to remain incomplete.

[Emre Yigit 0]

Thanks very much. This is really a Map Editor for Dummies. I was able to get my first map done the first time through (though actually rendering it was a different matter!). Thanks again.

[Gobbo 1]

I am trying, my English is not so good, so for me it is not very simple to understand all details. But I have at least one problem: I cannot browse the image from the Global Mapper to Irfanview without registering to Global Mapper....

[bblubb 1]

You do not need to export the image from Global Mapper. Just press the "Print Screen" button on your keyboard change to IrfanView and press Ctrl & v.

(please pardon me for digging out the dead. i haven't noticed the thread date before posting)

[OffshoreTacos 5]

When doing screen captures from Global Mapper. you might wonder what zoom level to use. I zoom in until each tick on the scale legend (lower-left corner) represents one kilometer. That way, each Km is about 66 pixels on screen. That's pretty close to the SC4 standard of 64.

[sgt_spike 0]

this is great however, where does one go to get info on roads and building to recreat a real city?

[MallowTheCloud 41]

Hi everyone.

I don't visit Simtropolis often anymore, but I feel sort of guilty leaving this incomplete! I don't even have the mapping programs on my computer anymore, and I'll have to relearn a little on how to do this (though this tutorial will ironically help in that aspect ), but I'll try to complete this tutorial over the coming weeks!

[GMT 389]

very great tutorial!

but...

anyone keen on translating all the picture editing parts into photoshop?

[MallowTheCloud 41]

Bump!

Okay, I'm not going to fool myself. I probably won't get around to completing this tutorial, at least not any time soon.

I'd like to, but I'm just so busy and I have lots of other things to do in my free time.

But, first and foremost, I think the part that's complete gives a pretty good idea of where to begin. Secondly, who knows? Maybe I will finally dredge up enough diligence to get this thing done!

Just letting you all know that I still exist. Whether or not anyone cares, I donno.

[blade2k5 1,523]

I do old friend. How ya doing by the way?

[MallowTheCloud 41]

I'm doing fine! I graduated in June and am one of the fortunate ones to have a job right out of college.

It looks like you've been keeping up with the map making, and your maps are incredible!

[blade2k5 1,523]

Originally posted by: MallowTheCloud

I'm doing fine! I graduated in June and am one of the fortunate ones to have a job right out of college.

It looks like you've been keeping up with the map making, and your maps are incredible!quote>

Glad to hear that.  I don't think I'll ever stop making maps, it's in my blood like I was born to do it  Have you been over to Devotion yet?  I'm sure the guys would be tickled pink to know you're still among the breathing 

[MallowTheCloud 41]

Originally posted by: blade2k5

Originally posted by: MallowTheCloud

I'm doing fine! I graduated in June and am one of the fortunate ones to have a job right out of college.

It looks like you've been keeping up with the map making, and your maps are incredible!quote>

Glad to hear that.  I don't think I'll ever stop making maps, it's in my blood like I was born to do it  Have you been over to Devotion yet?  I'm sure the guys would be tickled pink to know you're still among the breathing 

quote>

Not yet. I should definitely stop on by over there, though!

[drunkapple 1,743]

G'day Mallow,  

Nice Tutorial and the best for finding where dem data hides.  A couple of questions I have,

Is it standard of the software to lift the edge of the coast outof the water? I could see in gm the shape of the coast with some grey outside of it, obviously this needs to be lowered by repainting the grey scale as there is a ring of islands around the land mass.

Also the whole of the land mass is cliff face at the shore, is it a fuction of gmapper to eradicate this or paint it out in gimp?

Cheers

drunk