final step of repro is to spawn static mesh actors that have CanEverAffectNavigation to true, on same ground plane as player unit!
Here I have a Level BP that can be used to test this!
Again I used a static mesh standard cube from starter assets of third person template, and scaled it by 10 as its own blueprint, and then spawn that blueprint on key press.
My fps drops by about 30 in editor via PIE each time I press P key, until local changed component of Nav mesh gets to rebuild itself.
Please note I am using default Navigation Mesh settings, though I tried turning Voxel simplification on and off without any noticeable change in behavior.
This drop of 30fps each time I press P key is issue I had with my game that caused me to revert to 4.3, because in my game new actors that affect navigation are created relatively frequently, and I was therefore always losing 30 fps that I was not losing in 4.3
Here is a fully functional sample project of <50MB download which demonstrates issue!
#Once You Download
in editor PIE you can go in game, and observe fps drops by a lot while nav mesh is rebuilding, as low as 30 on first build
successive rebuilds at runtime averaged a loss of 30 fps for me on my computer, if your computer is super fast you may have to make nav mesh bigger.
You can press P key to repeatedly spawn colliding Static Mesh Actors 512 units from player unit, which on my machine cause a loss of 30fps until nav mesh finishes rebuilding
Again if your computer is really fast you may need to make my sample nav mesh bigger!
Let me know how your tests with my sample project go!
#Download Link Again, < 50 MB
Copy will tell you folder is read only, dont worry, just find download button and it should download just fine
I’ve just repro’ed everything I discuss above several times, it happesn quite reliably, only variance now would be your computer’s specs vs mine, and a bigger nav mesh should resolve that.
Issue nailed down and fixed (CL#2343690). 4.6 will contain fix. Turned out to be “cosmetic” - NavmeshRenderingComponent was gathering navmesh data to be drawn over-zealously, even when navmesh was not being drawn.
Good news is this bug does not affect cooked builds at all.
A local quick-hack-fix would be to comment-out internals of UNavMeshRenderingComponent::GatherData, but that will result in disabling navmesh drawing. Alternatively you can check GIsEditor to have navmesh drawing only in editor.
Can you open a new answerhub post on this? There have been significant changes to navigation system so bug you are seeing may be completely unrelated to this thread. In it, please describe what specific drop you are seeing is, when it is occurring, and what steps you are taking to reproduce error. Please include if it happens in a clean, blank project with no additional content. Thank you!
