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LambdaTrain | 4 years ago

Just want to make sure if I correctly understand what it means by "triangle": For navigation, the developer triangularize the skyrim world, and these divided triangles are not the same size - for example, a 100-sq feet field is covered by one triangle, while a 100-sq feet point of interest is more complicated and covered by more triangles. The original design intention is that the number of triangles encodes the sense of distance, but maximizing the #triangles actually leads to interesting places.

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FeepingCreature|4 years ago

Right. Another way to think about it is if you reproject the Skyrim map so that each navmesh tri is equally big, a surprisingly large area would be taken up by points of interest, and foxes target a random point in a radius around the current point in that reprojected map.

alephxyz|4 years ago

Another way to think of it is that foxes travel in more or less straight lines in the curved navmesh-POI space (/s)

Const-me|4 years ago

> The original design intention is that the number of triangles encodes the sense of distance, but maximizing the #triangles actually leads to interesting places.

The design intention was saving resources.

The game probably streams the nav.mesh along with map tiles; the cost is disk I/O and RAM. Once the nav.mesh is in RAM, the game runs raycasts or A* search or whatever, the cost is CPU time. In a big flat nothing, NPCs can walk any direction they want without colliding into things, having a dense nav.mesh at that place would be a waste of resources.

The fox AI doesn’t quite maximize anything. It does something similar to random walk over nav.mesh triangles. After long enough time, random walk algorithm causes the fox to be randomly distributed over nav.mesh triangles, i.e. probability to be in any particular nav.mesh triangle is about the same. However, because nav.mesh triangles have very uneven area, the fox distribution over space is very uneven too. The fox is way more likely to be in places with dense nav.mesh because that’s where the majority of nav.mesh triangles are.

prox|4 years ago

Yeah, you can open the skyrim map in the Creation Kit and see the navmesh. You could even remake the navmesh as you see fit in a mod.

junon|4 years ago

Yeah they made the decision to judge total distance in the fox's pathfinding by number of triangles, not by actual world distance.