I wonder if that's the problem on the workshop or on the uploader (... or downloader) side. If it isn't Valve doing these changes, we can likely hack together a custom uploader/downloader, fixing this one and other issues (like being forced to use BSAs) along the way.

Last night after few days of working on my mod, navmesh bug has finally materialized itself for me. I'm building a nice retreat in the existing cell on the existing landscape next to a water mill. I had to adjust the landcape a bit to fit the house and of course I had to rip the existing navmesh apart and rebuild it to suit my project. The retreat is close to cell border and I have not touched the navmesh in the neighbouring cell or triangles that connect the border.

I've tested the navmesh before and it was always fine as long as I only fast travelled. Last night for the first time I put one of my characters through an hour of regular gameplay to test the mod. I first went for a little hunting in the neighbouring cell... from there I fast travelled to a nearby city. While in the city I went to the inn. After a while I came back via fast travel to the cell neighbouring my retreat cell. And that's when it happened. Lydia was still following me but right at the border of two cells all of a sudden she turned around and attempted to find another route to me, around the mill and through some bushes. One NPC that was at the time walking from my house area to the mill was standing still at the border of the two cells. It almost looked like the connection of navmesh triangles between two cells was disrupted but it was very localized and not enough to completely stop Lydia in her tracks.

After finding an alternative path to me, Lydia resumed following me into the house where things got stranger. On the ground floor Lydia was still following me allthough lazily. When I took her to the basemant, she would follow the further into the basemant we went but would not come back. I hit the save button, exited the game, came back and the issue vanished... all was good again.

I have to say, I really hope they fix this because this definitely put a shadow on my modding mood last night. It's nice to see that they acknowledged the issue and I hope something will come out of it. Skyrim is such a beautiful game and with CK we can literally move the mountains but not without properly working navmesh.

This doesn't help with the workshop's shenanigans, but it seems to me the easiest way to handle this from a workflow perspective is to do all work on the esp. Once its at a release-candidate stage then use a low-level editor to make an esm, copy the cell and navmesh records over, and switch the esp records to override records instead of originals.

I love how he repeatedly pronounces "Bethesda" (Beth-ez-dah) as (Beth-zed-uh)

Well if you're doing dungeons, you could always make them "The only way out is through" style like the Blind Pit one. Thus, no way to go two zones away and then back without completing it anyway.

Yeah the meshes are there, but the bug makes its as if there was never any nevmesh placed in to begin with. Lydia trying to find a path to you proves this.

God no, path grids are a pain to set up compared to navmesh. Navmesh is far more reobust and allows for more fluid NPC movement. Pending issues aside, the technology is leagues better then path grids.

This sounds like the software simply isn't loading the navmesh from ESP files if the dungeon is already instanced...Doesn't the game keep the last cell you were in in memory, since there are a lot of times you go back and forth between one zone and several others (like in a town), which would explain why the navmesh is still there if you don't zone twice before returning, so Where I would start looking for the problem is checking to make sure the function that loads and initializes the navmesh is in the code that loads the cell in the game, and not the code that initially reads the file to get the cell. In other words, it should load the navmesh when you hit the door to go in, not when it reads the ESP file to get the cell in the first place.

it could be storing the Navmesh as a local variable rather than a global one, so when the cell deloads, the navmesh data gets dumped. Given the difficulty I've had making variables retain their values, I wouldn't be surprised if that's really what's going on.

At least if I were looking for this bug, that's where I'd start.

Whats going on in better detail is on page 4. They ARE there, but they aren't the originals. They are deleted by the CK, and then replaced with a mesh with an entirely different form. As a result, the game goes stupid.

As for Pathgriding... NOOOOOooooooo D:

Unless the Pathgrid generator works this time ;p.

I'm afraid I'm with her on this one. Path grids were way easier to set up and worked perfectly fine. I could path grid an entire exterior cell in ~10 minutes and have enough granularity with that to achieve smooth enough movement that end users wouldn't know the difference.

It takes HOURS to set up one navmesh in one cell and as far as I can tell in game, it doesn't produce a substantially better experience. Escpecially once it breaks and you have to exit the game to get it back. We should not be expected to engage in shenanigans to get our cells working right either.

Put simply, modders are FAR more productive with path grids than they can ever be with navmeshes. If they get fixed though, I'm certainly willing to live with the added time investment.

So if I decide I wanted to make something like...lets say a 4 story forge, it would suffer from this same bug? =/

Actually, better question, if I changed some items in an interior cell...like some Dummy Weapon's Leveled Lists, would that cause a Navmesh bug to occur?

I'm all sorts of paranoid of this bug now lol

The way I understand it, the moment you decide to make anything requiring addition of new or alteration of existing navmesh, you will suffer from this bug. I made a two storey farmhouse and I've been hit by it. Both the altered navmesh in the exterior cell and the new navmesh inside the house go wacko when I start playing the game and travel the world.

If that's a 4 story forge made up of new cells, yes. Guaranteed to be affected by it.

If it's an outdoor structure that can attach to a vanilla navmesh, you can avoid the pain by making sure you give the navmesh an editor ID before starting work. It's the only workaround we have right now.

Still SOL even then though if you have to cause the CK to split the navmesh you're working on and forcing it to assign a new ID to the newly split section.

I think that this is by far the most needed bug fix in the game. I've long suspected this was why the Fallouts didn't get anywhere near the number of quality quest mods that Oblivion got, in spite of having largely the same modding community. All those Oblivion quest mods increased the value of the game for me tremendously, and their absence in Skyrim would be a huge disappointment.

Wow... major blow here... I've been working hard on trying to learn the CK so that I could start modding in Skyrim, and then I see this. I was going to make a dungeon.

It wasn't made clear: Does Esmifying the .esp with Wrye Bash resolve the issue? At least for in the interior?

Its the complete opposite for me. I can set up nav mesh in no time. Its so easy for me. And as i said, current issues specific to Skyrim aside, i am of the strong opinion that navmesh is far superior.

This article basically explains the difference (Im sure you know the difference XD) and why navmesh works better then path grid.

http://www.ai-blog.net/archives/000152.htmlasically I feel that nav mesh allows for smoother turns and easier ability to dodge other NPCs and the player walking the other way, where as path grids, you need at least 2 paths to keep NPCs from running into one another, not to mention, you can cover an area faster with navmesn. Take a 2048x2048 unit area. you can cover it with 4 points of navmesh, or at least 16 points of path grid for decent coverage.

You should try navmeshing empty city squares some time. 4 points doesn't even begin to cut it

Yes, I get the difference and fully understand the arguments. Had Bethesda not produced a broken implementation of them, I've already said I could deal with it taking hours to set one up. Keep in mind I'm talking about a full 4096x4096 cell of open city space, not a farmhouse you can path in 3 minutes using either method.

Oblivion path grids were dead simple to produce. I could have had all 5 Skyrim cities done and out the door 2 weeks ago if we'd still been using "waypoint graphs" as that article terms them. Plus the NPCs would not be acting like complete dunces, and I wouldn't have been forced to re-finalize every interior navmesh in a city either just so the doors would link.

Maybe I misunderstood what the issue is, but I've been trying to reproduce the bug the video talks about and my navmesh seems to work fine (an interior navmesh)

basically I'm making a mod that enlarges inns in cities, I started with the Bannared Mare and added a basemant level with some rooms, navmeshed it and connected it to the existing one (including stairs to the basemant level). I tested it, exited the inn then whiterun, fast traveled somewhere else then returned. npc's were walking fine. I console-moved some of them to the new level and they walked through it correctly? did that twice and no issues

Again, Im the complete opposite.

To each their own I guess.

Sigh, I think I have become the latest victim, I was just on the verge of releasing my house mod, too. I got the spouse to move in, the farmhand was tilling the soil outside. The quest to get the key went smoothly. And the spouse was doing all sorts of interesting things with my idle markers. The voice-acting svcked, but that's my own fault. Life was good. After leaving for some time to check the schedule of another NPC, I come home to the spouse standing around, yawning, appropriately enough. Hitting WAIT gets the spouse to teleport to a new location, but unless it's the bed, no new animations queue. I'm assuming this is the Navmesh bug. I hope we're able to come up with a work-around, since so much of what makes the world "livelier" depends on working Navmeshes. It's not such an apocalyptic thing that people should quit modding, though. Either Beth will fix it or a community workaround will be reached. And there are so many fantastic things in the CK that DO work.

I saw one post that mentioned scripting the NPCs - is this a workaround? I mean, will it work? I have a new interior cell (a mine) and will be putting new NPCs in it. I don't know much about scripting, but if that's the only way to get the NPCs to follow a schedule (mining, eating, sleeping), then I will learn what I must.

This almost escaped my mind... better ask now.

For those of you who play/played FO3/NV and used the GECK, is there also a warning that pops up on load? Since the bug originates from the GECK.

For the CK it is the NevmashInfo 00028e37(which tells you there is no parent space).

It's just a hunch of mine..maybe that there could be the key to this whole mess.

It's been ages since I last loaded the GECK, and it isn't installed right now, but I'm pretty sure it had errors on startup. I very much doubt it's the same one though.

Could be. When I fire up the CK, I get a navmesh oriented warning. When I get home, I can post eaxectly what it says.

What Beth needs to do is add a new function to cells called "ForceNavMeshReload()" that goes back to the Cell File and re-applies the NavMesh information (only) and is called automatically when the player enters the cell from any other cell.

They will need to fix this debacle. Here's to hoping they will.