How to create a resources overlay map in GIMP

A simple step-by-step guide to adding colored overlays for each resource to an image of your map. This is handy to include when adding your self-made maps to the Workshop or for planning out the development of your Soviet Republic.

Read this first

Note: You may need to install the GIMP dds plugin to handle dds files. If so, follow eg this guide to install it: https://tech4fresher.com/gimp-dds-plugin/.

Tip: It might be wise to save a copy of your progress after eg step 6 in case you screw something up while/after merging layers in steps 7 onwards.

Your final result will look something like this:
If you want my Great Lakes/Southern Ontario map, get it here: https://steamcommunity.com/sharedfiles/filedetails/?id=2348615092

Step-by-step guide

1. Open the Workers and Resources map of interest, eg mine was:
C:\Program Files (x86)\Steam\steamapps\common\SovietRepublic\media_soviet\workshop_wip\2348615092

2. The resource maps are the files: resourcemap.dds, resourcemap2.dds

3. Open the two files as well as your preview image of your map in GIMP or Photoshop (GIMP is free), eg previewimage.png (assuming that's an image/screenshot of the actual map).

4. Resize previewimage to the size of the dds files: 1024x1024.

5. Copy the red, green, blue channels from "resourcemap.dds" (oil, iron, coal I think) and red+green channels from resourcemap2.dds (uranium, bauxite) as layers (not as channels!) for previewimage.png. Drag and drop seems the easiest way to do this.

6. Flip each of these new layers vertically, eg using the "Flip" tool. Just make sure you have the "vertical" direction for the tool selected and the layer you want selected, then just click on the main editing area to flip it.

7. Colorize each resource layer, ideally each a different distinct color (in GIMP go to "Colors" menu, click "Colorize" and select the color you want (you can click on the color sample in the pop-up dialog box to change the color).

8. Use the magic select tool (set it to "select by color") to select the background (ie: the part of the layer without any of that given resource) for each of the resource layers. When a given layer has the background selected, make it transparent by clicking Layer->Transparency-> Add Alpha Channel (if it is blanked out then that's already done)->select Edit -> Clear.

9. Click on each layer one at a time and set the opacity slider to eg 50% if you want to be able to see through the overlays.

10. Make sure only the colored resource layers are set to visible and then merge all visible layers. Merge this combined layer down (right click on the layer and select merge down) onto the map (preview image) layer. You may need to move the map layer down in the layer list to be able to merge down onto it. You can also do this merging until after the next step, but I prefer to do it now. Just make sure not to completely merge down onto the map/previewimage - it will make selecting the colors for your legend rather difficult.

11. Draw/fill a white semi-transparent box (eg: 40% or 50%), add labels for the resources, and add a colored symbol (use the color picker tool to easily pick the colors).

12. Right click on any remaining transparent layers (it may have created one for the text, etc) and merge down, so that there is only one layer with everything combined.

13. Export to png.

[Karosieben]

You could also use "Color > Color to Alpha" in Step 8 to not have those sharpe edges.

[Thamibn]

is it possible to do a quick video for this please?

[sergetechone]

Thank

[Ganggreener]

@sergetechone. Thanks! I made the Southern Ontario map, which led to the creation of the notes for this guide - so I could easily remember how to make the resource overlay image for my other maps.

You can get the Southern Ontario map here (I've added a link to the guide as well): https://steamcommunity.com/sharedfiles/filedetails/?id=2348615092

[sergetechone]

Nice tips. I wonder where did you got the Southern Ontario Map, and I hope the map is upload in the Workshop.