SSE New Navmesh in Tamriel Cell

[RichWebster]

Hey guys, having made big changes to an existing exterior cell, ideally I could do with having a whole new Navmesh rather than edit the existing one.

 

I know I shouldn't delete it, but how can I do a fresh one? Should I just lower the existing one and draw a new one? Or would that be an issue?

[TheDungeonDweller]

Yeah, take the entire cell(s) navmesh and place it under the terrain, and make a brand new one from scratch. One of the best ways to avoid editing vanilla navmeshes. You will also have full control and not be sitting there feeling lost on what to do with whats in front of you. I found that a lot of vanilla exterior navmeshes are hard to work with.

I made a list of things you can safely do with vanilla navmeshes a while ago back when I was working on an exterior one:

• You can move vanilla vertices, triangles, and edges around.
• You can create new triangles via edge splitting, but most be done on a vanilla triangle.
• You can create new triangles from existing vanilla vertices.
  • You need to select two vanilla vertices and while holding control, place down another vert and hit the A key to from the new triangle.
• You can delete most vanilla triangles.. too many will result in an error. Best to try not deleting any.
• You can move the entire navmesh from the cell way up in the sky or down below and make your own navmesh from scratch.

Don'ts:

• You cannot link a custom triangle to a vanilla triangle. The adjacent triangles will have their FormIDs changed and the vanilla navmesh will be silently deleted by the CK.
• You generally should not be deleting triangles. Deleting vertices could result in deleting many triangles.
• If you NEED to delete triangles, makes sure you do it carefully and not to create an "island" of navmeshes. The CK will change their FormIDs.

 

As long as a vanilla triangles' FormID is not changed, things are ok. My do's/don'ts aren't complete, there may be other little things to look out for that I haven't personally encountered.

To prevent confusion with triangle deletion, I follow the practice of deleting none, even if doing so to a few the CK will let slide. If another mod references the deleted triangle, you know that's a CTD.

Edited June 7, 2017 by TheDungeonDweller

[RichWebster]

Thanks mate, so I just drag it down and start a new one. Will it get those yellow blocks on the edges adjacent to the other cells? Not sure how they'd generate.

Edit:

Or is it a case of ignore those and just make a new one, and the game will take the old markers into account?

 

 

Edit 2

 

I see now. Moving the whole mesh down and creating a new one, that lines up with the adjacent cells, creates those new markers on the new navmesh. Sorted.

Edited June 7, 2017 by B1gBadDaddy

[TheDungeonDweller]

Yeah, the green lines are cell borders meaning the cell navmeshes are linked. Removing a cell navmesh will break the link but will not affect the adjacent cell navmeshes.

I have not got this far, but I read the cell border verts need to line up with the border verts of another cell. I recall observing such behavior with the vanilla navmeshes.

Edited June 8, 2017 by TheDungeonDweller