Randomized Patterns Make Interesting Map Fills

Randomized patterns can add texture and variety to an otherwise flat map. This is an especially good effect for representing features with naturally occurring randomness, such as ground-cover and forests. Ortelius has several tools in the Style Inspector to help you make awesome randomized patterns.

Tutorial Details

Program: Ortelius 1.6+ for Mac OS X
Difficulty: Intermediate to Advanced
Topics Covered: Style Inspector
Estimated Completion Time: 25 minutes

Start with a Shape


Create a shape to be used for your pattern. Here we’ll use the Regular Polygon tool with a nice green fill style to make a shape. You could use the Freehand Path or Bezier Curve tools to make a similar shape that isn’t quite as symmetrical. In the Geometry panel we’ll adjust the shape to have 6-sides, turn on the “Star” shape option and adjust the “Tip” setting to about 70%. We end up with a clover-like shape that we’ll use to represent a tree.

Prefer doing things hands-on? Give it a try…


Make a Sandbox for your New Pattern


Use the Rectangle tool to draw a rectangle for your sandbox. We’ll play in here and you’ll be able to see your pattern as you are creating it. With your sandbox selected, open the Style Inspector and choose ‘Reset’ to reset to the default style. For now your rectangle looks like a dull grey box – but don’t worry, it’s going to get exciting fast!

Add a Pattern Fill


Click the “+” button to add a new Style Component. You’re going to add a “Pattern Fill.” Now, click the shape you made earlier and copy it (CMND-C, right-click > Copy, or Edit > Copy in the main menu). Then paste the shape into the image-well for your Pattern Fill by clicking ‘Paste Image’. With the default settings you are going to get a nice evenly spaced pattern like you see here.

Randomize Pattern


Now, let’s have some fun. You can go ahead and turn off the existing Fill and Stroke by disabling them (un-checking) in the Component list.

We hated to do it, but “Rand” stands for randomized. Why? It’s a long word and we’ve simply run out of room. Okay. So, the best way to get familiar with how these settings work is to play with them. Just keep in mind, very small and closely spaced patterns start using a lot of memory and may slow things down a bit. To get this particular look, we changed the Scale setting to 60%, Spacing to 0, Rand Spacing and Rand Scale to 100%, and Rand Angle to 25%.

Note, in the Inspector you may be seeing units expressed in “cm” or “km” or something rather than “pt” (points) as you see here. You can change your display units by choosing View > Display Units > in the main menu and selecting Points, Drawing Units, or Map Units.

Suppress Clipped Images


But what about those shapes cut in half along the edges of our rectangle? That doesn’t look very natural.

Click to enable the “Suppress clipped images” option to keep most images from getting artificially clipped at the edges of a shape. Here we see how it looks on an irregular shape (right-click to quickly Copy Style and Paste Style onto a new shape). Sweet.

When you’re satisfied with your new style, click on Style in the components list to name it and save it to the Library.



Now that you understand how to make a randomized pattern, go ahead and experiment. For example, you can also use existing images and even Ortelius symbols as the basis for your pattern. Clicking “Image file” in the Style Inspector pane will let you select images from a file on your computer rather than pasting your copied graphic. In that case, small images with alpha-transparency (i.e., no white background) work best.

Here we’ve used the Symbol Stamp tool to add a tree symbol to our canvas. We then copy the symbol and paste it into the Style Inspector to create a different pattern. Since we don’t want these upright trees placed at funky randomized angles, we’ve changed the Rand Angle setting to zero. We’ve also upped the Scale back to about 60% since the image is pretty small already and this pattern does start to slow things down a bit. While for a small area like this or simple effect you could as easily use the Symbol Stamp tool and place symbols individually, it’s easy to see how handy randomized patterns can be.

You’re on your way to creating interesting map fill styles. Have fun!