Documentation on Navigation and Steering

[anonymous_user_f3fb80e6]

Thank you very much for your reply.
I do have some follow-up questions indeed

@MieszkoZ;268179

Under the hood we’re using Recast (google it, there’s lots of info on it online) and it’s using regular A*. We’ve approached the idea of implementing hierarchical pathfinding on top of that, but we didn’t get satisfying results in dynamic worlds such as Fortnite’s. It’s kinda there, but we don’t market it as a full-blown feature until we get time to get back to it and make it bullet-proof.

Ohh yes I know Recast, at least I have had a talk on that at the last GameAI conference in Vienna. Besides, personally I have had some good experience with Jump Point Search (in open areas), and I would like to implement it in UE4. Now, do I need to pull off a whole new path finding solution from scratch in that case, or can I implement JPS with some kind of interface and plug that class into the built-in path finding framework within the engine, so that it would be used automatically instead of A*?

@MieszkoZ;268179

Most navigation queries allow you to specify NavigationData instance you want to use for the query. NavigationData in regular, out-of-the-box use cases are just RecastNavMesh instances.

So if I understand you correctly, then I can use multiple nav meshes, but can only specify one certain mesh at one navigation query, right? If that is the case, is there any way to navigate from A to B if A lives in nav mesh 1 and B lives in nav mesh 2? So, can I navigate from one mesh to another mesh?

@MieszkoZ;268179

To annotate navmesh with “areas” you need to use “navigation modifiers”. Those are actors that implement INavRelevantInterface. The easiest and ready-to-use modifier is NavModifierVolume - just put it on the map and pick navigation area class to use. Now to change the cost dynamically that’s a bit more work - you either need to dynamically change the cost associated with selected nav area type, or configure navigation query filter (FNavigationQueryFilter) to use virtual calls while calculating traversal cost during A* search (expensive, but as flexible as it gets).

Thanks, I will have a look at that.

@MieszkoZ;268179

Not yet, sorry. AI Documentation is behind a bit

The documentation is great already for many parts, it just lacks details in some sections, like AI. Are there any plans and ETA for when this will be addressed?

Also, I have another related question: Does UE4 provide any built-in solutions for steering behaviours (e.g. avoid, flee, follow, etc.), or do I need to implement that on my own from scratch? In the latter case, do you have any recommendations where it would be best to plug such a custom solution in?

Thanks again!