We have frozen bodies of water in our game – and these are constructed by having a flat terrain for ice that intersects with typical ground terrain. The terrain under the ice drops down, like it would for a pond/lake. We need navmesh on the ice and on the terrain surrounding the ice.
The recast graph generates navmesh for both the ice and terrain – however I think there is a problem if a pathfinding entity starts on the terrain, then it tries to continue using the terrain navmesh even when the entity moves on top of the ice. In other words, the AI wasn’t able to “transition” from the terrain navmesh to the ice navmesh, and ends up walking in place (presumably because it can’t get close enough to the desired terrain navmesh point, which is below the ice).
This is probably an uncommon use case, but I am wondering if there are some ways to solve or work around this problem?