Navmesh below ground and in air

[Sophie]

I am making my first navmesh, and I am having some trouble understanding how the placement of edges impacts the game's pathing logic.

1) If I position some vertices and edges in the air above the ground in a dungeon, will my NPCs look like they are floating? Do the vertices have to be exactly at ground level to prevent bad things from happening?

2) Sometimes I place two vertices so they are right on the ground, but there is a hump in the ground between them. So some sections of the edge between the two vertices disappears underneath the ground. Is this a bad thing? Will it block pathing?

3) I have tried using the "Set Pathing Test Attributes" popup. It seems to generate two shades of colors on the map - a dark one that is mostly in the room interiors, and a lighter shade that runs along the walls. In thin sections the dark can sometimes not be present. I'm having a hard time interpreting this. Can someone explain what I'm looking at? Does it have something to do with the Avoid nodes attributes "Node radius"? Do "underground" edges affect the shading?

Thanks!

[Corinze]

1) Meshing should be flat on the ground. Mesh is like a stream or current for NPC to follow, it should be smooth and continual for best results.
2) It is nature to have unlevel flooring/ground pop through the mesh.
3) Don't use anything auto for NavMesh in the Creation Kit, just do it manually.

Just remember to never never delete navmesh.

https://www.youtube.com/watch?v=yipvn925ju8

https://www.youtube.com/watch?v=5JGpfOLiLic

https://www.youtube.com/watch?v=uJYiV4E8xCc

[Chaosium]

Just tried it, on a flat floor with elevated navmesh, actors remain nicely on the floor and don't start floating around. Hitting F also snaps a vertex to ground level, that's handy to avoid floating navmesh

[Altbert]

I can't anwer all your questions as navmeshing has always been a horror to me! For interior cells I always use Recast-Based Generation. This will leave a certain non-navmeshed area near walls and other objects. Then I check the green carats of a triangle to see if these are floating above ground. The green carat should be halfway into ground level. If above ground level, I use "Drop Vertices" in the NavMesh bar to move those to ground level. If below ground level I delete the triangle and try to find a proper spot and try again. Stairs are another navmeshing disaster. If generation has placed any navmeshes under the stairs, delete those as you just can't get navmeshing of the stairs done. Navmeshing works top-down and not bottom-up. With one of my mods, I received great help from Corinze. Maybe he will join in on this thread and can give you more answers.

EDIT: Corinze already joined the thread!!

[Sophie]

Thanks so much for this info! It's very helpful.

I'm experimenting with the pathing test popup. I'm mystified by some of its results in the simple rectangle/two triangles room I made. The test radius affects the width of the light colored band around the dark center, but I still can't figure out why some paths work and others don't.

[Altbert]

When I use the Recast-Based Generation for interior cells, it will give me a basic navmesh. The player can walk anywhere and doesnt' really need any navmesh, but for followers the cells need to be fully navmeshed. In areas where there is no navmesh generated, I will go ingame and take a walk there. If I can walk there, followers also will, and I will adjust the navmesh manually.

I have no clue about pathing test popup. Never used it. For interior cells Recast-Based Generation, manually adjust navmeshes, and always top-down navmeshing.

[Corinze]

Always finalize before testing and closing the navmesh tool.

If you are in an exterior cell, say in a corner of 4 quadrants, you sometimes need to finalize in atleast 3 of the 4, weird but sometimes needed, if you are redoing the green boundaries.

[Chaosium]

The test radius seem to automatically adjust with the size of the NPC you're using as a test, you can see some pretty big changes between humans and e.g. mammoths

[Sophie]

I give up. I think that to understand the pathing between adjacent navmesh cells we will need to know what funnel algorithm Bethesda decided to use.

[Corinze]

So you are outside in an exterior cell. Post a pic from the CK of the issue.

Rebuilding those boundaries is not really that bad.

[Sophie]

Can I post pics here? I don't see an upload button.

[Corinze]

Post it anyway you feel comfortable with, a youtube clip would work too.

To get a pic from the CK.

Use PrintScreen and past it onto Paint, than save as a .jpg into the Steam screenshot folder.

Totally sign out of Steam and log back in - or - Launch a game and close it, and the pic you manual placed will show up in the upload folder.

Once uploaded copy and paste the link from Share here.

[Sophie]

Working Pathing test for units =400 [ibb.co]

[Sophie]

Non-working Pathing test for units =500[ibb.co]

[Sophie]

I'm trying to figure out what is causing the larger radius test to fail. I know actual people are quite a bit smaller. Maybe I am just breaking the algorithm with an extreme value, but I had hoped to get some insight from this test.

[Sophie]

I get similar results in a two triangle navmesh, with smaller radius values