[LE] Navmeshing exterior is giving me fits

[greyday01]

I'm trying to navmesh a section of exterior. It has 4 islands. 1 Big one and 3 others. I selected each with floodfill and dragged them down below the surface then started making my own mesh. It will work for a while. My new mesh island is listed along with the original 4 then suddenly my mesh disappears and is merged with the ID of one of the original islands. I don't know what triggers this merge because the original islands aren't even close to touching my new mesh. I've been saving my mod stage every few triangles and keep having to revert back. I'll get it done eventually, the square is about half meshed but it surely is frustrating. One question. The adjoining squares now show as edited though I haven't changed anything in those squares. Can I just after I finish the mesh I'm working on just delete the changes in the adjoining squares with TES5? I've been matching my vertices as close as possible to the ones across the borders.

[cumbrianlad]

I'm afraid that I don't have an answer for you.

 

I'm keeping an eye on this thread because I'm interested in knowing the answer, myself!

 

I've read elsewhere that some people avoid editing existing navmesh by placing collision boxes around items like trees and statues. They ensure to size them so that the collision box extends through the navmesh and assign L_Navcut to them in the primitive tab.

 

This has come from some pretty experienced modders. If they don't like to mess with vanilla navmesh, if at all possible, I think that says something!

 

Here's one such quote..

 

"I'm not an expert, but I've been fighting navmesh issues with my Helgen Rebuilt mod for months. Here's a few things I've learned or have been told to do or not to do.

 

1- NEVER delete an island navmesh. Move it underground. Also, NEVER connect an island navmesh to a non-island navmesh. This essentially deletes it because it is no longer an island if it is connected back to a normal navmesh.

 

2 - Wherever possible, try to just move existing verts around to accommodate what you're trying to accomplish.

 

3- Others may disagree with this one, but in certain places, I try to use primitives set to L_NAVCUT to cut the existing vanilla navmesh where I place objects in the middle of a navmesh. For example, say I place a tree somewhere that's already navmeshed, I can select the tree, click on the create trigger button and it will draw a primitive around the tree. Make sure it is penetrating the navmesh, and set it to L_NAVCUT, and it will cut out the navmesh where it goes through it.

 

Lastly, you might not be able to do what you are trying to do without getting warnings - especially the one about "bounds" missing. I have one I cannot clear up, but everything seems to still work correctly."

 

I don't know if that helps you or confuses you more!

[Tasheni]

I was just navmeshing the first time the exterior of my created farm and found this information from Arthmoor, that helped me a lot:

 

Di0nysys, on 28 Sept 2015 - 6:20 PM, said:

Revert all the edits u did to vanilla navmesh. Then manually select all the triangles u want removed, and drag them all the way down under the terrain.
Then create new triangles connected to the main navmesh around ur house area. Never delete vanilla navmesh.

Arthmoor: This isn't necessary. It's perfectly safe to delete selected triangles from the vanilla navmesh. It only becomes an issue when you delete the ENTIRE vanilla navmesh in a cell. Case in point: Every mod I've ever released that needed navmesh work both adds and deletes triangles from vanilla navmeshes. They work just fine.

 

@wizardsmith: Do the edits you need to do. Be careful NOT to remove the navmeshes entirely. When you're satisfied, you need to go into the two cells you edited and use the functions to find "cover edges" and "finalize". This will properly restore the borders between cells and they should light back up in green as expected.

 

You should then check it for ITMs and deleted references in TES5Edit to make sure nothing went wrong in the process.

So I didn't need to drag the original navmesh away, what I tried first but was pretty much complicated. I have now deleted the triangles below the house and trees and other places and connected my new to the vanilla one and it's working without issues. Perhaps this may help you.

Edited October 17, 2017 by Tasheni

[Di0nysys]

If you're creating navmesh for a new custom exterior, the CK has a built in procedural navmesh generation tool. Go to Navmesh > Havok Based Generation, tick "Use landscape data" and hit ok. It'll take a few minutes depending on your machine. I've navmeshed entire worldspaces with this method. The downside is it has to be done cell by cell, and it may in some instances, not work properly with object mesh surfaces (platforms, stairs, etc) but it's great for landscape.

[Aragorn58]

As DiOnysis says use the CKs built in tool to generate navmesh for areas that are not that critical like forest areas or mountains. But areas that are close to villages, homes, or along roads, I have found it much easier to do them by hand rather than generate them automatically and go through and fix the errors.

[greyday01]

I've got a tower embedded in the side of a mountain. Part of the original mesh is under the stairs up to it. I would need to do quite a bit more that to move a few vertices to reach the door so it seemed simpler to create my own navmesh. I really think Bethesda did a bad job with the original. It looks autogenerated and never cleaned up. There are islands that should be connected and almost look like they are but aren't including one 3 triangle one the size of a sliver between sections of the main mesh, and a 25 triangle island that is halfway up the mountain and has no access.

[Aragorn58]

If you take into account the size of the Tamriel world space, I'm thinking they did as I mentioned in my earlier post. In your case if you are only removing few triangles and replacing them with your own you should not have any issues. I have done this myself on several occasions without problems. As long as you do not remove the entire vanilla navmesh from the cell.

 

I miss read your first post thinking the "islands " you were speaking of a new world spaces and not navmesh islands.

[nerdofprey]

I was just navmeshing the first time the exterior of my created farm and found this information from Arthmoor, that helped me a lot:

 

Di0nysys, on 28 Sept 2015 - 6:20 PM, said:

Revert all the edits u did to vanilla navmesh. Then manually select all the triangles u want removed, and drag them all the way down under the terrain.

Then create new triangles connected to the main navmesh around ur house area. Never delete vanilla navmesh.

Arthmoor: This isn't necessary. It's perfectly safe to delete selected triangles from the vanilla navmesh. It only becomes an issue when you delete the ENTIRE vanilla navmesh in a cell. Case in point: Every mod I've ever released that needed navmesh work both adds and deletes triangles from vanilla navmeshes. They work just fine.

 

@wizardsmith: Do the edits you need to do. Be careful NOT to remove the navmeshes entirely. When you're satisfied, you need to go into the two cells you edited and use the functions to find "cover edges" and "finalize". This will properly restore the borders between cells and they should light back up in green as expected.

 

You should then check it for ITMs and deleted references in TES5Edit to make sure nothing went wrong in the process.

So I didn't need to drag the original navmesh away, what I tried first but was pretty much complicated. I have now deleted the triangles below the house and trees and other places and connected my new to the vanilla one and it's working without issues. Perhaps this may help you.

 

Holy crap, if this is true this is a serious game-changer! I'm going to have to test this tonight. I have recently been working with navcut boxes, and that's been working just fine for what I was doing... but if I could safely delete a few triangles, wow, that would make things work so much better!

[Aragorn58]

 

I was just navmeshing the first time the exterior of my created farm and found this information from Arthmoor, that helped me a lot:

 

Di0nysys, on 28 Sept 2015 - 6:20 PM, said:

Revert all the edits u did to vanilla navmesh. Then manually select all the triangles u want removed, and drag them all the way down under the terrain.

Then create new triangles connected to the main navmesh around ur house area. Never delete vanilla navmesh.

Arthmoor: This isn't necessary. It's perfectly safe to delete selected triangles from the vanilla navmesh. It only becomes an issue when you delete the ENTIRE vanilla navmesh in a cell. Case in point: Every mod I've ever released that needed navmesh work both adds and deletes triangles from vanilla navmeshes. They work just fine.

 

@wizardsmith: Do the edits you need to do. Be careful NOT to remove the navmeshes entirely. When you're satisfied, you need to go into the two cells you edited and use the functions to find "cover edges" and "finalize". This will properly restore the borders between cells and they should light back up in green as expected.

 

You should then check it for ITMs and deleted references in TES5Edit to make sure nothing went wrong in the process.

So I didn't need to drag the original navmesh away, what I tried first but was pretty much complicated. I have now deleted the triangles below the house and trees and other places and connected my new to the vanilla one and it's working without issues. Perhaps this may help you.

 

Holy crap, if this is true this is a serious game-changer! I'm going to have to test this tonight. I have recently been working with navcut boxes, and that's been working just fine for what I was doing... but if I could safely delete a few triangles, wow, that would make things work so much better!

 

I've done exactly that several times in mods I've released also in personal ones without issues. But I imagine if two modders happen to edit the same triangles there could be a problem just like with anything else.

[Urtho]

Two mods editing the same navmesh record is a standard mod conflict like any other - the rule of one applies as usual and last loaded mod wins the record conflict resolution so the earlier loading mod that loses the conflict will have its unique navmesh overwritten by the winning mod.

 

Conflicts like this need to be patched with both mods being ESM-ified either in xEdit or Wrye and the patch having both mods as masters.