[Award Winner] Using GIMP to Create an Artistic Regional RPG Map

[RobA]

Post 11:Let There be Mountains

Before you continue, there is a better way I found to make mountains located over here. It works well with the rest of this tutorial, and seems much easier and predictable than what follows here...


The technique for making the mountains is very similar to that of making the land. Because we have an idea for a map, we will start in this case by sketching a blurred representation of where they should be. Otherwise, just use one of the random techniques:

Create a new layer “Mountains”. Fill in white for the general areas of the mountain ranges, and apply a 50 px (or so) Gaussian blur. It is helpful to keep the original sketch on top with reduced opacity to act as a guide. Don’t worry about going in to the sea, because we can we can erase those areas later:
Post11-1.png

Now the noise layer (I used detail 8 and size of and set the blend mode to multiply. Then add a third layer (remember the TLS) as a clipping layer, and use the levels dialog to bring it down to show the mountains you want Here is the screen showing the three layers
Post11-2.png

Use the magic wand again to select the non-mountain area (like with the land) and create a new layer called “Mountains Mask” with a white on black. (Also the white colour selection as a new selection mask using Select->Save to Channel).

Now we want to create a heightfield from this. The easiest way I have found to do this is to copy the current visible image (Edit->Copy Visible) then paste it (CTRL-V) to a floating selection. Click the New Layer button to get it on its own layer rather than a floating layer. Now stretch the colour range out (Color->Auto->Normalize):
Post11-3.png

Rename this layer to “mountain colour”. Make a duplicate and call it “mountain bump map”. Now set the foreground colour to “lowest dirt” and the background colour to “highest dirt”, and on the “mountain colour” layer, do a Color->Map->Gradient Map.
Post11-4.png

Normalize the colours (Colors->Auto->Normalize) and add a layer mask, using the mountain mask channel. (Note, the Dirt layer was turned of in this image by accident).
Post11-5.png