I’m trying to create a Strategy game with an interactive map like Hearts of Iron, Europa Universalis and so on. From the Wiki of Europa Universalis I found out that they achieve this by working with different layers of maps/textures that they then read data from and populate the game with.
So at the moment, I’ve already created a Color map of my world (Included in the post), and I use RayCasts to identify what color that I hit with my cursor, and which province/part of the world that color corresponds to.
But now I want to add Graphics and Image effects. For example, I want to highlight the province in the game when I move the mouse over it, or perhaps draw interactive borders around the provinces in-game.
As I understand it (Please correct me if I’m wrong), to do these things I need to have Mesh’s that are in the shape of my provinces in game. It’s not enough with just a Map Texture. So, I need to generate a mesh from my color map, that I can then wrap with borders, add UI elements to or highlight when it’s selected.
Where do I start out with this? I’ve found some tutorials of generating meshes in simple shapes such as Squares or Rectangles. But countries and provinces on a world map are not shaped as squares. They got very complex shapes.
Can anyone point a few fingers where I should start? Is there some functions where I can track the color of a Texture, get coordinates of it and then generate a Mesh out of that? I’m completely lost and I’d love some pointers.
are these areas going to change size/shape during the game?
if not you’re probably going to have a far easier time using a modelling package to cut up a plane with a knife tool using the the image as a “background” to “trace” and using the resultant meshes in your game
Well, the provinces themselves will not be able to change their size or shape, however a Country will be made up by multiple Provinces. So the borders of the country will expand if the country acquire a new Province (However the shape of the mesh/province will not update).
you could “brute force” it and go with 1 vertex per pixel, but you might want to consider something like quadtrees (start with a low res and work out where the edges are with increasing levels of detail).
You could also make every edge pixel a vertex and use the triangulate script from the wiki to make it into a mesh.
I also feel like some shader magic might help. It should be possible to pass in a particular colour to a shader, along with your colour map, and say “highlight where this colour appears”. Of course I have no clue when it comes to shaders, so I can’t offer you more advice.
