NavMesh Gap, SimpleMoveTo, updates?

Build: 4.1.2
System Specs: i5, GTX 460, Win7 64


I noticed that SimpleMoveTo( ) sends our characters to world center when not finding a PathGoal inside the NavMesh after a “valid Hit” click, this can happens if the NavMesh doesn’t covers the hit area, but it still being valid.

While activating the NavMesh preview, I noticed that it is built with a Gap from the map edges.

I’ve tried to reduce the Agent Radius and also almost zeroing Draw Offset but this doesn’t makes the NavVolume start to build the NavMesh fitting the maps’ ground surfaces more preciselly…


I didn’t updated to 4.2 yet due to the CustomMovementComponent problem people have reported, is this solved on it or should I wait for 4.3?

Hey Creasso

Here’s are some thing that could make it so you nav mesh does not fill the area entirely

  • Agent Size
  • Cell Size
  • NavMesh bound volume

Agent Size to 0
Cell Size to 1
and having the NavMeshBoundsVolume over the entire area should make you navmesh fill the full zone

I tried with both 4.1.2 and 4.2.1

Hopes this helps

Hi creasso,

Check to see if in Project Settings>Navigation System you have supported agents. If so, please make sure that the agent radius is reduced as well as this will override the navmesh agent radius.

Hi and …

No success when dealing with the settings the gap persists, also, I have no agents at all. :frowning:
My volume covers the entire level (it’s small).


Hi Creasso,

Have you tried adjusting the cell size? It seems like you might be able to adjust this to get the coverage you are looking for.

Until on Cell Size 1.0 the gap still exists (Also near walls).
A new problem with decreasing cell size is also that this starts to distort the navmesh “coplanarity”.

and …

Did the changes you suggested, but got few modifications on the NavMesh…
On despair (lol) began to tweak every other parameter and so I found the Region and Layer Partitioning building rules (if you watch my previous screens) I was using Watershed…

After change the building rules to Chunky Monotone all your tips began to work a lot better.

… Could you please tell me if use a chunky navmesh does impacts too much on performance? I tought this result is great and also gave me a lot of ideas…

Thank you both by the answers.

Hi creasso,

There are a few differences between watershed, monotone, and chunky monotone that should be kept in mind when deciding how best to approach your needs:

• Watershed
o best result = polys should be matching level’s layout (rooms, corridors, etc)
o slowest method

• Monotone
o worst result = split using XY axis without using level’s topology
o often results in creating long & thin polys, which are bad if you want to use path corridor for anything (doesn’t represent how much space agent really have)
o fastest method

• Chunky monotone
o acceptable but not great results
o splits tile into pieces (by default 2x2) and run monotone partitioning on them
o long thin polys are still being created, but split limits them to – hopefully – single chunk and in general they won’t be that long (again: less space to work on)
o creates a lot of polys
o very fast

There are also two options for partitioning:

• Layer = which method should be used to divide tile into 2D layers
o monotone/chunky = axis aligned tile boundary = good
o watershed = best split, but curved tile boundary will end up as a lot of small polys
o speed doesn’t really matter here

• Region = actual navmesh in 2D layers

Hopefully this helps you on your way!

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I’ve been struggling with this myself. It turns out you need to add an agent to the Navigation Systems section of the project settings, set that agent’s radius to 0, and then reset the editor. It doesn’t seem to update the nav mesh unless you restart, and the agent radius in the Navigation Mesh section doesn’t seem to make a difference.

So what one should he / I use?

Hey nmills3,

It depends on what exactly you’re trying to accomplish. If you provide a bit more information about what you’re looking to do I can give you more information about how to go about getting the results you’re looking for.