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. Here’s how…
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 tree-like shape. You could use the Freehand Path or Bezier Curve tools to make a similar shape that isn’t quite as symmetrical. In the Object Inspector – Features pane we’ll adjust the shape to have 5-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.
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 – Expert pane and choose New Style from the Action Menu (looks like a gear). 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 tree-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.
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 40%, Spacing to 0, Rand Spacing and Rand Scale to 75%, and Rand Angle to 50%.
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 half-trees 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, 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!