Hello guys.
i’m facing an issue i’m not understanding ( beginner )
When my navmesh volume does not update (when something is moved), every thing run fine :
But when I set it do dynamic here :
Everything is going crazy 
Am i doing it wrong ? Is it possible to update it like once per second and not more ?
I am just searching the equivalent to this :
Try to remove that nav mesh, enable the Dynamic option on Project Settings and add a new Nav Mesh into your Level.
Unfortunately, that’s not better. But thank you anyway for the try !
i’m trying some changes to get clue of what happening but nothing for now
Here is some more parameter I set :
Can you explain why nav mesh is blocked on the 2nd gif?
I suggest to modify those values only once you got the nav mesh working properly.
I strongly recommend you to create a new level and just add into there a nav mesh (dynamic) and a blocking volume (tree, animal, etc.).
Thank you guys for your answers.
There is no nasmesh modifier in my level, just character blueprint ( cow and chiken, and actor blueprint for the tree)
The more i’m doing testing, the more i’m realising that maybe, a character SHOULD NOT have “Can ever affect navigation” enabled, because when it’s time to AImove, then it is blocking itself in fact i think.
So i should just enable collisions, and it would be fine, but when a cow have to move to a new location, it will not take in consideration a cow on its path ( but it will collide with it)
I hope i’m clear. I think i do not have the right approch here, and don’t even know if this is possible for a character affecting navigation to calculate its path igoring himself)
The portion of the navmeshvolume where there are characters turns red ( just this area) every time it update itself, then turn green again. but here, it is updating continuously so always red
( I made new tests from a scratch project, and I got the same behaviour. A character seem not to be able to have affect navigation enabled, or, in the other way, something having the ‘affect navigation’ enabled, can be move manually, but can no move itself)
In fact, all i need is an “ignore self” option for navigation. Does it exist ?
Yes I think I’m right, someone had the same issue and find a solution on UE4 but I can’t find the same trick in UE5 :
Can you disable collision here?
Maybe it’s better to just Set CanEverAffectNavigation to false regarding to characters pawn.
Yes I think that’s it. I don’t know how other poeple manage this. But the characters are running and colliding in each other if there are moving on one other path …
I found the avoid parameters in the characterMovement but can’t manage yet how it works as it seem to do nothing here ( or not updating at runtime)
By default, characters don’t affect navigation. Do you changed that?
Yes exactly. i’m searching a solution to make character avoid other character getting on their path when moving to a point
Oh, I got it.
Hopefully this may help 
Using Avoidance With the Navigation System | Unreal Engine 4.27 Documentation
Well I have finally found out how to solve my issue. The solution is simply to change the ai controller class.
Hope it helps someone else
Can’t find how to tag it as resolved… I wonder why every basic things are complicated with epic games !
Please teach me how can i change the ai controller class? where is it?
@paulzuo
Change the AI controller class to "Deteor AI Controller class and in the AI character under Character Movement Component, check the option “Use RVO Avoidence”
