You've mentioned something in the video about ability to draw decals only on selected objects while they currently draw on top of the terrain - I'll add that functionality to the next release.
Game::World.pathBuild() I think it now has "2D" added into the name, however this is only for the old 2D path system in EE 1.0
I see that you have a bottom floor, and then on top of it boxes appear, do you need to have pathmesh created on top of the boxes as well? If no, then you can just have pathmesh created at the bottom, and then add path obstacles for the boxes.
If you need however to recalculate full navmesh, then you can try using this:
PathMesh.create
it requires MeshBase of all of the meshes in the area, area coordinates, and PathSettings
you'd need to setup custom PathSettings (areaSize member can be obtained from Game.World.settings . areaSize), all other members currently would need to be entered manually, you can open World Editor and copy the values from path settings.
Once you have a PathMesh object for that area, you need to call Game.World.path().set(&path_mesh, and area coordinates)
this is however non const method (set) but the path() returns const object, but you can convert it to non const object using this way:
define 2 global functions:
<TYPE> TYPE& ConstCast(C TYPE &x) {return (TYPE&)x;}
<TYPE> TYPE* ConstCast(C TYPE *x) {return (TYPE*)x;}
ConstCast(Game.World.path()).set(..)
Oh, forgot about the last thing, probably I'm repeating myself, but.. your video looks awesome