Nodelink2 and NavMeshCut Issues

#1

I am joining two disconnected areas with Link2 component. After a manual scan in editor it joins the two areas properly:

Path1%20copy
Path1%20copy1452×992 345 KB

After I run the application, the areas do not appear connected in the editor and the agents are not seeking to the Nodelink2 (there is a jump pad at each end). I have tried disabling cache and enabling scan at startup and results are same.

Path2
Path21407×892 254 KB

Astar version 4.2.8. Unity version 2019.2.9.

There are two hacky ways I have found as workarounds but would like to avoid using. Agents seek properly from either end and area joined properly if I do either of these:

  1. Connect the two areas using one additional two way Nodelink. Set the priority value high so agents try not to use.

  2. After a short amount of play time - disable and enable one Nodelink2 component. This fixes all the Nodelinks and things appear ok. I tried doing this in GraphsPostUpdate but does not work (too early?).

I also tried iterating through all Nodelink2 components on Start and calling OnGraphsPostUpdate and this does not help.

Note this is a recast graph and I have tried moving the large platform so it is not over any other path areas. I do have one additional recast graph that I use for checking out of bounds but not for seeking. Results are the same on this one. (This one not visible on my samples)

Thanks.

#2

The Graph Post Update isnt always called. Try switching to something like PostScan

#3

No, it definitely gets called every time for me. (Twice in fact). Also tested that everything that receives the override is responding ok. I have previously tried many things including OnPostScan and OnLatePostScan.

#4

I’ll try recreating this on my side

#5

I was not able to reproduce this issue

image
image1020×807 265 KB

I haven’t played around with the Link2 system before, So you’ll have to wait and see @aron_granberg can help you on this one

#6

I have narrowed it down a bit more. It seems NavMeshCuts are causing problems with Nodelink2 connections. Does not matter if one way or two way.

I have made a video to show the problem. Nearby (not overlapping) NavMeshCut will cause Nodelink2 to lose connection. Disable/enable the Nodelink corrects the problem. Moving the NavMeshCut around will provide weird results. Hopefully the video will show better:

https://youtu.be/orsi73GlUy0

1 Like
#7

Here is an ugly hack that fixes things. Not intended for actual use but might shine some light on a clean solution for this. (It works ok but adds an extra NavMeshCut that is not needed - just using for the override).

If I override OnGraphsPostUpdate instead of UsedForCut it does not work.

// Attach this script to each NodeLink2
namespace Pathfinding
{
public class NodeLinkFixer : NavmeshCut
{
NodeLink2 nodeLink;

    protected override void Awake()
    {
        base.Awake();
        nodeLink = GetComponent<NodeLink2>();
    }

    public override void UsedForCut()
    {
        if (this.enabled) {
            nodeLink.enabled = false;
            nodeLink.enabled = true;
        }
    }
}

}

#9

Aron, thanks for the reply. Just to note that I got the email version of your post but it is not appearing in this thread for some reason. Really useful details in that post for others as well.

That explains a lot to me and gives me another option. I will probably go the route of adding a non used 2 way node link for performance.

#10

Hi

Yeah, I noticed you were not using one-way links. So my post was kinda irrelevant.
However I did find some bugs related to node links. Especially in combination with navmesh cuts.
I have uploaded beta version 4.3.8 now which I think should fix your issue.