Pathfinding with Recast/Detours and NPC on different Level

[hjalplos]

Is it possible with Recast/Detours to take into account the Z-variable?
From the source-code:
/// Intersection tests occur in 2D. All polygons and the search circle are
/// projected onto the xz-plane. So the y-value of the center point does not
/// effect intersection tests.

My biggest problem is pathing to a vendor on the second floor. The path ends right under the Vendor on the first Floor!
How would you go about implementing a solution to this? Traceline up the stairs?

From another Forum post people shot down another users idée of using Recast/Detour in a Pixelbot. This works really well most of the time. Considering the pathing is mostly done in 2D.
Now I'm working on another project and I'm inprocess and got Traceline working if needed.

Just wanted to bounce of some ideas.

[Bogie]

Hi,

I haven't worked with Pixel bots before, so just to understand - is your issue that you cannot find out the z-coordinate of yourself and/or your target (vendor, in this case)?

In principle, if you specify the start and end points correctly (including correct z values), Detour should be able to find the path just fine, including having to e.g. walk up stairs to get to the desired level, i.e. recast/detour will absolutely take z-values into account for navmesh & path generation.

[badusername1234]

Are you trying to find a path by raycasting..? Don't do that, that's not what it's for

You need to use one of the polygon finding methods to find the polygon you're standing on and the polygon the vendor is on, then findPath will get the polygons that your path goes through. Then findStraightPath will turn that into your 'actual' path to follow.

Whether or not you're using a pixel bot is irrelevant as long as you have all three of your position coordinates - it's extremely difficult to get them accurately by just looking at the screen, though

[hjalplos]

Are you trying to find a path by raycasting..? Don't do that, that's not what it's for

You need to use one of the polygon finding methods to find the polygon you're standing on and the polygon the vendor is on, then findPath will get the polygons that your path goes through. Then findStraightPath will turn that into your 'actual' path to follow.

Whether or not you're using a pixel bot is irrelevant as long as you have all three of your position coordinates - it's extremely difficult to get them accurately by just looking at the screen, though

I've been using Pathfinding with a Pixelbot before with good results. But this specific problem is with using Detour and I'm in process I got the X,Y,Z coordinates from player and destination.
This might be a Mesh problem I'm just not that experienced with Detours Pathfinding to know why it fails to path up the flight tower in ogrimmar for example but pathing to Azhara from Ogrimmar works just fine.
It then creates a perfect Path and uses the Flighttower to get there.

My problem is: Pathing to Flightmaster with known XYZ and player XYZ Fails. BUT! Pathing to XYZ at the same elevation as the flightmaster but for example right outside Halls of Legends works just fine. (Path will go right up the flighttower as expected)

[Bogie]

My problem is: Pathing to Flightmaster with known XYZ and player XYZ Fails. BUT! Pathing to XYZ at the same elevation as the flightmaster but for example right outside Halls of Legends works just fine. (Path will go right up the flighttower as expected)

It's probably quite hard to identify the issue just with the infos given, but what I can definitely say is that Detour absolutely supports this, so it should indeed work. Meaning, it will be an issue with either your nav mesh, our your navmesh query.

I'm assuming you're using dtNavMesh->findPath.

First, I would double check that the end poly + the position on the end poly is the one you're looking for, i.e. the one on which your target NPC actually stands. (Presumably, you're querying the target poly + target position on navmesh throuhg dtNavMeshQuery->findNearestPoly).

If poly & position on poly are indeed correct, have a look at the return value of your dtNavMesh->findPath call. Is the return status == DT_SUCCESS, or does it have any other flags set (eg DT_PARTIAL_RESULT)? The previous check would already encompass that, but you could also keep an eye whether the last dtPolyRef in the path you're getting from findPath() is indeed your target poly.

As a side note, if you're using the navmesh generation tools that come with any of the usual emus (cmangos etc) - those include a customized version of the RecastDemo which allows you to debug/visualize your generated navmesh.

[hjalplos]

Nvm it works now... I don't know why or how but I sent the same Z-value as start and destination but right x, y values...