In CC3+, we use polygons a lot. They are used when you draw a landmass, they are used when you draw the floor of your building, they are used for your terrain fills and so on. Basically, when you work with a CC3+ map, there are 3 main types of entities you deal with, your symbols (places, objects, markers and more), your polygons (for filled areas like landmass and floors) and your lines (for walls, roads and similar).
Now, for this article I am going to have a little look at how we can do things like split our polygon up into two pieces, for example if we only need part of it for another map. And, I am also going to look at how to properly join up two polygons into one, as due to various factors, just drawing two partially overlapping polys and leaving them at that doesn’t always work.
In truth, lines and polys are mostly the same thing, the main difference is that polygons are closed (i.e. the programs draws a closing segment between the end node and back to the start node) while lines do not have this closing segment. When we are splitting and joining out polygons, we’ll actually be temporarily turning them into lines, so it is worth noting already now that having the fill apparently disappear while doing this is completely normal, and it will return when we are done. This also means that the procedures described here are the same for both lines and polygons, except you don’t close up lines at the end.
If you’re after extracting part of your map to make a detailed local map from a regional map, you may also wish to check out my Large to Small – Going from Regional Maps to Local Maps article.
Now, I use landmasses for my example here, but this works exactly the same way with floors in dungeon maps and all polys in all other map types as well.