This short tutorial will use only basic Gimp skills and give you a map of the form of those classic TSR maps of the 80s such as The Palace of the Silver Princess, that can be found for free here. I will try to keep it as simple and straightforward as possible. If there are any steps - however small - that are unclear please say and I will amend the text.
Throughout this I will be using gimp version 2.4 - go to www.gimp.org to get hold of the latest stable (2.4.x) release.
In this post we'll go through the following steps:
1. Open a new canvas of the right size
2. Set up Gimps grid to be the right scale for the map
3. Import a new pattern (only ever needs to be done once)
4. Use the new pattern to lay a grid over the canvas to make our graph paper background.
So there are very few steps and they should be pretty straightforward. If you want to see the result of this section of the tutorial, skip to the bottom of the post.
Before we start we need to decide what size the canvas is going to be. This depends on two things - how large the map is in numbers of squares and how many pixels each of those squares will take up. Here I use 50px squares and a canvas of 1000px by 1000px. This means that there are 1000/50=20 squares to a side so its a pretty small map. I've chosen 50px because it's a good resolution for virtual tabletop programmes which are the area I play D&D in.
To get a larger map you can go to a larger overall canvas - ie a 2000px by 2000px map will hold 40 50px squares to a side which should hold a decent sized dungeon. The alternative is to go to smaller squares. If I had chosen a 25px square then I'd get 40 to a side on my 1000 by 1000px canvas. This second option has the advantage of keeping the filesize down. On the other hand, all the resources I'll post here will be sized to 50px
So that's enough talk about this. You should now have decided on the size of your canvas. I take 1000px by 1000px. Create a new canvas (File->New). In the following dialogue, make sure the measurements are in pixels that your width and height are both set to the value you have chosen.
You now have a blank white square!
Gimp has a grid built in. It's invisible at the moment so go to View->Show Grid. Note the View menu is in the window with the canvas on it, rather than the window with the tool palette on it. We'll be using the canvas menus for everything except for opening a new file (and that's already done).
Now with the grid showing you should have a load of cross-hairs across your white canvas. These will probably be at the default Gimp spacing of 32 pixels - which you don't want.
To change this go to Image->Configure Grid... and set the grid spacing to your chosen value. Here I set it to 50px. You should now have something that looks like this:
This grid just works as a guide for the Gimp tools - it won't show up in the final version. However that's no good for us as we will be needing a grid to form the basis of our map. We need to draw in a grid, but don't worry, you won't need to draw out every line by hand. We'll use a pattern fill.
This next step is a little tricky but you only have to do it once. I've got a couple of pattern (.pat) files that allow me to create a grid of any size with great ease. They are included in this zip file:
Download this zip file and unzip it in the following directory:
C:\Documents and Settings\<userName>\.gimp-2.4\patterns\
Now make sure that you have the patterns dialogue open somewhere (by default Gimp will open this in the combined layers and patterns dialogue). If you can't see it, go to Dialogs->Patterns or use ctrl-shift-P. That will bring it up, or highlight it if it is already open. Now at the bottom of the palettes dialogue is a pair of circling arrows. This allows you to refresh the seelction of patterns. The button is here:
Hit this and the palette will be updated with the new patterns you have just added. Your palette should now look like this:
The new patterns are there and ready to use. You will never have to do this again - those patterns will always be there (unless you delete the files from the directory at a later date). One will give a black grid and the other will give a TSR blue grid. I'll use blue throughout for that added nostalgia factor. Click on the pattern you want.
Now, click on the window with your canvas in it. Go to Select->All or hit ctrl-A to select the whole canvas. Now go to Edit->Fill with pattern, or hit ctrl-;. You will now have a lovely blue grid that fits beautifully over the Gimp grid we set up! This will form the basis for the map. It should look something like this:
Right, best to save it here. Save it in Gimp's native format - .xcf - as this maintains all of the information. So call it something like classicDungeon.xcf and you are good to go.