Navigation Links not working or avoided

[GoalLine01]

Reopening Closed Issue Ticket: #137

The issue still exists. There is no clear documentation on how to use the Navigation Links, so I am assuming its broken.

My agents avoid them even when cost is -1 and state is walkable. Navigation Link's start and end pos are also handled in an odd way. Y float position moves into Z axis, and Z float position moves into Y axis.

Unity 6000.3.13f1

[h8man]

I added navmesh links in this project for testing https://github.com/h8man/RedHotSweetPepper
Can you reproduce this issue on that demo scene with links?

Please leave steps to reproduce so I can test it.

[GoalLine01]

@h8man that project is using Unity 2022. I am upgrading it to 6000.3.13f1. Hopefully that isn't the cause of the issue.

[GoalLine01]

1. Clearing your current navmesh area and hittin bake produces this error. One work around to actually building a nav mesh is to have the Navigation Surface component (Use Geometry) set to Physics Colliders instead of Render Meshes. I have to do this to my own personal project as well.

NullReferenceException: Object reference not set to an instance of an object NavMeshPlus.Extensions.NavMeshBuilder2d.CollectTileSources (System.Collections.Generic.List1[T] sources, UnityEngine.Tilemaps.Tilemap tilemap, System.Int32 area, NavMeshPlus.Extensions.NavMeshBuilder2dState builder) (at Assets/NavMeshComponents/Scripts/NavMeshBuilder2d.cs:302)
NavMeshPlus.Extensions.NavMeshBuilder2d.CollectSources (System.Collections.Generic.List1[T] sources, NavMeshPlus.Extensions.NavMeshBuilder2dState builder, NavMeshPlus.Components.NavMeshModifier modifier, System.Int32 area) (at Assets/NavMeshComponents/Scripts/NavMeshBuilder2d.cs:204) NavMeshPlus.Extensions.NavMeshBuilder2d.CollectSources (UnityEngine.GameObject root, System.Collections.Generic.List1[T] sources, NavMeshPlus.Extensions.NavMeshBuilder2dState builder) (at Assets/NavMeshComponents/Scripts/NavMeshBuilder2d.cs:184)
NavMeshPlus.Extensions.NavMeshBuilder2d.CollectSources (System.Collections.Generic.List1[T] sources, NavMeshPlus.Extensions.NavMeshBuilder2dState builder) (at Assets/NavMeshComponents/Scripts/NavMeshBuilder2d.cs:154) NavMeshPlus.Extensions.CollectSources2d.CollectSources (NavMeshPlus.Components.NavMeshSurface surface, System.Collections.Generic.List1[T] sources, NavMeshPlus.Extensions.NavMeshBuilderState navNeshState) (at Assets/NavMeshComponents/Scripts/CollectSources2d.cs:87)
NavMeshPlus.Components.NavMeshSurface.CollectSources (NavMeshPlus.Extensions.NavMeshBuilderState builderState) (at Assets/NavMeshComponents/Scripts/NavMeshSurface.cs:374)
NavMeshPlus.Components.NavMeshSurface.UpdateNavMesh (UnityEngine.AI.NavMeshData data) (at Assets/NavMeshComponents/Scripts/NavMeshSurface.cs:229)
NavMeshPlus.Components.Editors.NavMeshAssetManager.StartBakingSurfaces (UnityEngine.Object[] surfaces) (at Assets/NavMeshComponents/Editor/NavMeshAssetManager.cs:124)
NavMeshPlus.Components.Editors.NavMeshSurfaceEditor.OnInspectorGUI () (at Assets/NavMeshComponents/Editor/NavMeshSurfaceEditor.cs:276)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass82_0.b__2 () (at <7e9d236df72e41199c1709cbdadee527>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)
`

Okay now onto applying a navigation link to your sample scene.

I will report back with results and steps to reproduce.

[GoalLine01]

While I cannot get the bake with meshrenderers working, I can verify that Navigation Links are working.

I tried multiple set ups - oddly the first time i attempted to build the navigation link, it did not work. But after restarting the entire process over by completely destroying and rebuilding the navmesh surface, I was able to get it working.

I tried:

1. Navigation Links across multiple navigation surfaces
2. Navigation links inside 1 navigation surface
3. Navigation links outside of the navigation surface hierarchy
4. Navigation link nested inside navigation surface

These all work!
Now, i just gotta figure out why its not behaving the same on my project. Perhaps it is a matter of fact of starting from scratch.

Important Observations & Requirements

• ONLY the navigation surface needs the -90 rotation.
• Navigation Links do not need rotations.
• ALL gameObjects need a position Z of 0 (including navigation links)
• Scale is untested. Does a scale of 0.99999 break the system???
• Navigation Link width variable has no affect (I know its "scaling" in Z, but ultimately Z doesnt matter)

Most Important:

• Navigation Surface Area voxel size MUST be 2-4 per agent's radius, as noted on the component. Only then Navigation Links Work!!! *

[GoalLine01]

After 2 hours of trouble shooting, I was able to get Navigation Links to work on my project. I strongly believe there is a "cache" bug here.

If the system at the time of creation doesn't work - it will no longer work when updating moving forward. My setup was all correct (rotations, z positions, layers). But for the life of me it did not work until I tore down the entire tilemap level, and in the same scene, created 1 simple square tile map and connected a navigation link inside of it. Only then it started to work moving forward.

I realize, that when the navigation is connected successfully, clicking on the navigation surface will reveal black crosses on both sides of the link.

I hope this all helps @h8man! It's a tough one!

[h8man]

• ALL gameObjects need a position Z of 0 (including navigation links) ----- you can override this with this field. It will pre-multiply every object, so you can fool it to think every object perfectly aligned on Z

• Scale is untested. Does a scale of 0.99999 break the system??? ------ it should work, Ill retest again. Scale and spacing should work for tiles also

• Navigation Link width variable has no affect (I know its "scaling" in Z, but ultimately Z doesnt matter) --- might be untested, Ill add samples with width.