There seems to be something I’m either missing or a bug with the ANavigationModifierVolume.
I drag and drop one in a new level with a navmesh bound volume. (Picture 1)
I hit build paths. (Picture 2)
Result is the same as (Picture 1), ie the NMV did not do anything.
If I am to check the box (Picture 3) on the NMV and hit Build Paths… I get the expected result (picture 4).
The exact same issue happens with UNavModifierComponent.
I investigated the code and what I found is that the checkbox (Mask Fill Collision Underneath for Navmesh) will flip the representation of my volume from Brush->Convex to Brush->Cube within the Recast implementation. It also seems valid… but when we hit DetourTileCacheBuilder::dtMarkConvexArea(…) we will hit the early out for null areas (DT_TILECACHE_NULL_AREA) all the time where as the cube version does not. So it seems areas are not computed properly when using the brush version? Pretty hard to debug/figure out. It’s happening in all maps, with various volumes. The gym I used was just to single out the issue.
