I'm working on a cross country racing mod and (for various reasons) the start and finish points need to be in "bleachers" that I've set up as prefabs.

Now I've built these things, given them a common enable parent so they don't clutter the place up when not in use and I can copy them to as many start and end points as I like. And it only now occurs to me that without navmesh the NPC racers will never be able to get onto the ramp up to the finish line.

Any ideas out there? I've considerd a few things:

• I could use portals like the ones at the end of "A Night To Remember" and have the initial and closing sections of the race in cells outside of tTamriel proper. I'm not adverse to this particularly, but my bleachers look awesome when deployed, and I'm reluctant to abandon them
• I could (given an open triangle edge) link a navmesh to that edge. The trouble is, I've no way to make the linked navmesh go away when I disable the belacher.
• I've read through some related threads on the forums, and I know I can use a primitive to cut navmesh so as to stop wildlife trying to walk through the bleachers.
• Someone also suggested A door could be set up between the regular mesh and that on the bleacher. I'm just not sure how to make the NPCs use the door, given that there's no portal defined on the mesh...

It's a tricky one. Potentially, I could create an open edge, link it to the walkway up to the bleacher, and then cut the connection with a primitive when not in use. It'd be tricky doable, although the deleted navmesh triangle worries me...

There's got to be a way to do this. Any ideas anyone?

I'm very much NOT an expert on this (nor really sure what you mean by "bleacher"), but you definitely need to navmesh anything you expect people to walk on. In terms of something being a temporary structure, there are certainly many precedents in the game and DLCs. For example, the Hearthfire DLC uses collision boxes and primitives to stop you walking where you're not supposed to be when things are disabled.

"bleacher" I use to mean a raised wooden platform with a ramp up and a few structures ... well cages in fact ... on top to represent the start and finish lines. I can dig up some screenies if that's at all helpful.

I need the wood becase I want them all lined up like a racing line, and there just aren't enough flat surfaces in skyrim. So I put them on a platform using wooden walkways and have a ramp to the ground and it works brilliantly ... except for the navmesh.

Hearthfire is a good point. They must have done somethign similar to link in the doors to the exterior mesh. But I'll bet they just used a navmesh cutter top open a hole - and there's still no flow from old mesh onto new walkways - you have to go inside and back out again... ack.