Many problems with the navmesh and how the NPC reacts to it

General Issues and Bug Reporting
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1

Summary

  1. Navmesh not detected by NPC when placed in uefn.
  2. Ai navigation modification device doesn’t remove the arrows coming down from an elevated floor or any arrows for that matter.
  3. Purple arrows pointing down from elevated floor or arrows perpendicular to a ramp/stair that don’t make sense at all.
    (READ ADITIONAL NOTES TOO)

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Devices

Steps to Reproduce

  1. Go to the island settings and enable:
  • Debug
  • Navigation
  • Verse Debug Draw
  • Fast Iteration Mode
  1. Place an NPC spawner
  2. Create an NPC behavior basic script, call it random_wander_behavior and paste the code I provided (might have to change 2 variables)
    new_npc_behavior_basic - Pastebin.com
  3. Doubled click the newly created behavior script and set:
    Type: custom
    Behavior: Verse Behavior
    NPCBehavior Script: Script that was just created
  4. Save and exit the window
  5. Click on the npc spawner and assign the newly created behavior to the “NPC Character Definition”

NPC setup is done, now:

  1. Create a square area with the AI navigation modifier as shown in the screenshot
  2. In unreal editor NOT FORTNITE add a 1st floor, ie: a stair and a couple of floors
    I used the ‘Yacht Deck A C12’ floor and the ‘Yacht Interior Stairs C2’ stairs
  3. Start the game

Expected Result

The npc should be able to go up the stair and and start moving to random valid locations found on the 1st floor

Observed Result

The npc stands still and does not count the navmesh as ‘walkable’ while trying to find a valid location on the floor height (y axis) set in the variable

If I had placed the building in fortnite instead of the editor it would have worked and the npc would be able to go up the stairs and randomly go to a point

Platform(s)

PC

Video

Videos of the main problem + all the problems listed in the additional notes
https://imgur. com/a/Frt9E1x (Remove the space), did not put the link as a whole because there are multiple videos in the link and it doesn’t show all of them in the forum if there is no space

Additional Notes

This is one of many issues I found with the navmesh system. Another issue is with the navmesh arrows, they make no sense at all, in a video I have provided you will see purple arrows pointing down from the first floor to the ground floor, this makes the npc think that it’s a valid way to get down when it’s not, so the npc gets stuck in that position until it finds a new one, same thing with the stairs, random arrow pointing perpendicular to the stair that makes the npc think it’s a passable point when it’s not.

Another issue is with the Ai navigation modification device, if I place it on the edge of a floor to remove all the arrows pointing down so that the NPC is not able to go up or down from the hanging floor, it does absolutely nothing.

Another issue is that because of the arrows pointing down from the floor even though the Ai navigation modifier is blocking the edge of the floor the NPC is able to escape the barrier by jumping from the first floor to the ground floor and escape the barriers set

Everything I talked about can be seen in the videos I provided, let me know if you need more information about this and I will be happy to provide more.

2

FORT-946999 has been created and its status is ‘Unconfirmed’. This is now in a queue to be reproduced and confirmed.

3

I have discovered that the issue is with the actual stairs, and because the buildings were placed in the unreal editor instead of fortnite. Although, when I place the buildings in the unreal editor, the green “walkable” navmesh is generated but not the arrows that allow to mantle and descend from a risen platform. Ff done in fortnite these arrow would appear.

EDIT: I recant what I have said. Yes, the issue comes from the stairs/building you choose. No, it doesn’t matter if the building were placed in unreal editor or fortnite

However, if the buildings were placed in unreal editor, they will not have the green, pink and purple arrows that indicate to the NPC that it can descend or mount from that point, which is good in my case because that’s what I am trying to achieve.

Now, if they were placed in Fortnite, they would have these arrows, which will mess up the navigation for the NPC as it cannot mount, jump, nor pass by some of the arrows as they are wrongly generated (for example the purple arrows pointing down from an elevated floor or the one in the middle of a ramp).

I will be adding some more videos showing the different scenarios.

4

Here is the video proof of what I was talking about, same thing happens with the ramp as seen in the screenshot

image
image1913×1062 232 KB

5

UPDATE: Can be Damaged has to be turned off, when you do, it wont generate these arrows, it was not very clear in the documentation but now I am guessing they were here as a point of reference for guards to smash through them, as this is a custom NPC it does not smash buildings nor chase a player so it did not try to break the floor but was considered as a passage point.
Hope this helps someone, and hope the other bugs I mentioned get resolved as well