# I need Help with the Nav Mesh Bound Volume **URL:** \ **Category:** Programming & Scripting\ **Tags:** unreal-engine, question\ **Created:** [March 24, 2024, 10:25pm UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590 "2024-03-24T22:25:44Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![seb-barr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@seb-barr](https://forums.unrealengine.com/u/seb-barr)\ **Post date:** [March 24, 2024, 10:25pm UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/1 "2024-03-24T22:25:44Z")
Hello there, I am a UE5 beginner I’m having trouble with my project that I just can’t seem to figure out how to solve. I’ll try to be as clear as I can (a little bit tricky). Here is my issue: When a new game is launched, the main map is loaded. Within the level blueprint of this main level, there are 3 other sub-levels loaded with the node EventBeginPlay and then Load Level Instance by Name (see the screenshot). The point is to create random parts of the main level. In those sub-levels, there are enemies to kill and puzzles to solve. ![help_1_00000](https://d3kjluh73b9h9o.cloudfront.net/original/4X/c/c/1/cc10410313c7f96196162fbbc853b6db3c1f9bac.png) However, the enemies don’t move around and don’t attack the player in those sub-levels (when the main map is loaded). I understood that the problem comes from the Nav Mesh Bound Volume, which doesn’t load properly in those sections, for some reason. I tried different things like putting only one huge Nav Mesh Bound Volume in the main level and NOT within the sub-levels, or the other way around, but nothing really worked. The Nav Mesh Bound Volume of the sub-levels just doesn’t load correctly. I would be very grateful if you guys could help me solve this problem. I haven’t found the solutions in this forum or on YouTube. ![help_2_00000](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/c/6/6c657b7a491c5a790f8edb44066637e2a1cc6741.jpeg) ![help_3_00000](https://d3kjluh73b9h9o.cloudfront.net/original/4X/3/a/f/3af6a96231775cc2bb618425d89b38346caf847b.jpeg) ---
**Author:** ![Leomerya12](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/leomerya12/32/926321_2.png) [@Leomerya12](https://forums.unrealengine.com/u/Leomerya12)\ **Post date:** [March 24, 2024, 10:58pm UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/2 "2024-03-24T22:58:45Z")
Hello, There could be the possibility that, during gameplay, it is being deactivated. You can have the NAVMESH persist to debug it during gameplay with this command: > [@Is it possible to view my NavMesh in PIE?](https://forums.unrealengine.com/t/is-it-possible-to-view-my-navmesh-in-pie/282218/9): > > To have the change persist, type this in the command console ShowFlag.Navigation = 1 ---
**Author:** ![seb-barr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@seb-barr](https://forums.unrealengine.com/u/seb-barr)\ **Post date:** [March 24, 2024, 11:27pm UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/3 "2024-03-24T23:27:18Z")
Yes absolutely, the NavMesh of the sub-levels seems deactivated when I open the Main level, perhaps it’s due to the node load level instance. Is there a way to force it to open ? Thank you so much for your help, I really appreciate it ---
**Author:** ![Leomerya12](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/leomerya12/32/926321_2.png) [@Leomerya12](https://forums.unrealengine.com/u/Leomerya12)\ **Post date:** [March 25, 2024, 1:58am UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/4 "2024-03-25T01:58:36Z")
Make sure to hit “REPLY” because it’s luck that I saw that you gave a response. Could you post a video so I can see what is happening? ---
**Author:** ![seb-barr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@seb-barr](https://forums.unrealengine.com/u/seb-barr)\ **Post date:** [March 25, 2024, 3:30am UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/6 "2024-03-25T03:30:50Z")
> [@Is it possible to view my NavMesh in PIE?](https://forums.unrealengine.com/t/is-it-possible-to-view-my-navmesh-in-pie/282218/9): > > ShowFlag.Navigation = 1 Yes I make a video to show you. Really sorry if my explanations are not clear, it’s kind of hard to explain and english is not my native language, obviously 😉 [![](https://d3kjluh73b9h9o.cloudfront.net/original/4X/0/c/2/0c27191d3b0ca9697284e36fea174005d2769957.jpeg "Aletheia\_for\_forums.unrealengine") ](https://www.youtube.com/watch?v=jiihtgtejgg) I’ll take any suggestion, thank you again ---
**Author:** ![Leomerya12](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/leomerya12/32/926321_2.png) [@Leomerya12](https://forums.unrealengine.com/u/Leomerya12)\ **Post date:** [March 25, 2024, 3:55am UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/7 "2024-03-25T03:55:47Z")
Ah, okay, that makes things much easier for me to understand! Thank you. So, you said it’s a “SUB-LEVEL”, so what I think is happening is that your NAVMESH is not in a PERSISTENT level. Open the LEVEL WINDOW to see what I mean: ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/d/0/9/d09345d23e98f1868618cdca6a9c724ecc024e89.jpeg) ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/d/7/5/d753b8332ac0e8ed4bd5dfd32f47321dd70c9f9e.jpeg) ---
**Author:** ![seb-barr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@seb-barr](https://forums.unrealengine.com/u/seb-barr)\ **Post date:** [March 25, 2024, 4:38am UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/8 "2024-03-25T04:38:18Z")
What I call a “sub-level” is a level loaded within the main map, maybe the termynology is confusing, sorry about that 😕 ![help_1_00000_00000](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/7/7/777a5dff5ef1c76d9e0abceb0b4f9f25a18df7d4.jpeg) ![help_2_00000_00000](https://d3kjluh73b9h9o.cloudfront.net/original/4X/5/6/4/564bbe6cbe13a335b12bd18076900a986a7d0225.jpeg) I’m not sure about the NAV Mesh, seems to be right, isn’t ? ---
**Author:** ![Leomerya12](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/leomerya12/32/926321_2.png) [@Leomerya12](https://forums.unrealengine.com/u/Leomerya12)\ **Post date:** [March 25, 2024, 4:44am UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/9 "2024-03-25T04:44:13Z")
Understood! There’s a few things you can try: Change “Should Discard Sub Level Nav Data” from TRUE to FALSE (Mine is set to TRUE). ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/9/6/1/9612687fc6dc0e6d1634651bb1ac376862092737.jpeg) Also, make sure this is set to DYNAMIC and not STATIC: ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/4/3/8439ebced889217b4ea0fe8e4e2991f74742b681.jpeg) ---
**Author:** ![seb-barr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@seb-barr](https://forums.unrealengine.com/u/seb-barr)\ **Post date:** [March 26, 2024, 1:14am UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/10 "2024-03-26T01:14:28Z")
It worked !!! The Runtime generation parameter (dynamic) solved the problem. The only slight downside: this change drastically lowered the FPS. I had to resize the NAV Mesh and optimize its location to increase the FPS. It’s not perfect (around 60fps) but it’s working ! If anyone else finds themselves in this situation, here’s what to do: delete all the Nav Mesh from the “sub-levels” and add one in the main map, and make sure the Runtime Generation is set on dynamic. Huge thanks to @Leomerya12 , you solved a problem I had been struggling for weeks. I owe you a coffee ; ---
**Author:** ![system](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/1/3/713c9d3f58553f0de89543d76a8a3a2779dc9fa4.png) [@system](https://forums.unrealengine.com/u/system)\ **Post date:** [April 25, 2024, 1:14am UTC](https://forums.unrealengine.com/t/i-need-help-with-the-nav-mesh-bound-volume/1770590/11 "2024-04-25T01:14:44Z")
This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.