Since I am now able to produce some nice looking screenshots, I think this is the right time to talk about the current state of the project.
I'm using the castle map for the example application, since each of it's rooms is a different sector. I have tweaked the colors from the default debug rendering code used in the Recast & Detour demo application, so it would look different and a little more visible in the map used. Here are a few screenshots: (light yellow edges for tile borders, dark yellow for other polygon edges).
Although it can't be seen from the examples above, even though I'm rendering all the navigation meshes at every frame, I cannot see navigation meshes through a portal. I don't know why that is happening, specially since the navmeshes are rendered directly with opengl, but I'm not worrying too much about it now.
There is still one problem related to building the navmesh. In order to make sure that a unit can walk in any straight path cast inside the navmesh, Recast removes a border proportional to the unit's radius from the navmesh (so the unit won't go inside a wall, for example). Since the navmeshes are being built independently for each sector, this generates a gap between two sectors where the unit can't move to.
The picture below is the bottom part of a door, which is a portal between two sectors. Notice that there is an area that should be walkable, but has no navmesh over it:
Recast uses the triangles from the collision detection data to build the navigation meshes. In order to fix the gap, I plan to feed Recast with some "fake" triangles, normal to the portal. This way, the border will be subtracted from these "fake" triangles instead of the walkable area.
In order to be able to see a path in the example application, you have to first set a source point (shift + left click) and a destination point (left click). The points are graphically represented by a cylinder, which has the same height and radius of the unit used to build the navmesh. Right now, the path is only calculated correctly when both points are on the same sector. Here are a few screenshots: (blue cylinder is source, green is destination)
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