I migrated my project from UE4.27.2 to UE5.1.0.
Reopened my maps, things seem correct overall.
I removed all options related to lumen etc in order to be closer to the performance of UE4.
The problem I am having now is when building light or building geometry.
As soon as I want to build light or build geometry, UE5.1 removes absolutely all actorsBP from the map.
While I have also lights in these bp (static and stationary), if I let the light build finish, the map is without these bpactors and lights, and they donāt reappear.
Save the map and reload it, make the bp reappear but none of these lights are built.
Iāve looked for it, but I canāt find what could be causing this.
Is this an engine bug or am I missing a ānew optionā that removes all BP/actors when building geometry and light?
If someone have a clue about this, thank you to let me knowā¦
Just fell on this via google so Iām not sure if itās known and discussed elsewhere by now. Apologies if it is.
This does seem to be a 5.1.0 bug with Build Geometry specifically. Itās causing any and all actor BP components to vanish from the editor, not even DefaultSceneRoot on an empty BP is spared.
With a fresh install and default settings:
Create new blank project
Create a new actor BP and add literally anything (cube mesh, box collision, wtva)
Compile/save and Build Geometry
The components completely vanish from the level viewport (the BPs themselves are still technically there) or as mentioned if itās a blank BP, the DefaultSceneRoot icon also disappears.
It affects other classes too. Cameras vanish from Character BPs for instance, and no longer show a camera preview when selecting the BP from the Outliner, indicating it truly believes there is no camera component and itās not just a visual bug. Lighting ofc wonāt build if it thinks thereās no geometry there to begin with.
Temp fixes:
Compiling the BPs again
Reloading the level or restarting UE
The game itself is unaffected when you play it (as auto recompile is on by default)
Itās as if Build Geometry is somehow compiling empty BPs which then get reflected in the viewport. Nothing else seems to cause it for me, just Build Geometry.
Ive only found it to be an issue in games if the Actor BP contains a light source. When this is the case, it causes the Stationary / Static light source to not be built, causing Unreal to render them all as dynamic.
This is in turn caused a 20% framerate drop in my game.
A temporary solution to the above issue is to create the light source outside the blueprint. This will break any code connected to the light, but at least you get the performance back.
Happening to me still in Version: 5.1.0-23058290+++UE5+Release-5.1 fwiw. When I do āBuild Allā then most of my static mesh BPs disappear and no matter what I do besides quit & restart, I canāt get them back. Only in the editor, they are visible in-game.
This still appears to be a bug in 5.1.1. I did a bit of investigation to unblock my own project, and it seems to be related to the command MAP REBUILD ALLVISIBLE being run.
This is run automatically if you hit Build ā Build all Levels, but not if you just go for Build Lighting Only, so that can be used as a workaround.
ā¦ unless that is, you happen to have BSP brushes in your level then you need a hack to stop that command from running (which it does with BSP in the world, even with Build Lighting Only).
This is quite the annoying bug. I have recorded footage on this thread here where I discussed my version of what is happening.
It seems to only affect my BP, any BP I create, and I choose to build my level, everything vanishes, but when T toggle any setting in details they reappear. The worst of it, is that when I try to make any change to the BP position in the Viewport, the BP actor disappears, and I have to toggle to view it again.
I have a video recorded at the very bottom (Do not open the others, your eyes will thank you later.)
If you can find something else you could figure out through my horrible quality video, or just in general, Iād love to know!
Are any of you using dynamic material instances on your meshes? Iāve been trying to nail down whatās causing the problem here, and so far it seems like itās only BPās generating dynamic material instances for their meshes in the construction script.
After so many trial and errors, finally we found a solid solution for this issue.
The problem is due to existence of BSP Brushes in the scene. If you have them in your scene, all BP actors will be disappeared during the light/geometry building process. To fix this issue, you need to convert the brushes into Static Meshes or remove them from your scene and then do the process of light/geometry building.
BTW, weāve tested this solution on UE5.1.1 and it works fine in this version.
This is also happening to me in 5.1.1, Even in a blank project with all the default settings. Anyone know if this bug was already reported? This bug is something big. It has been quite frustrating having to do a lot of workarounds to see things workingā¦
I thought Iād give UE5 one more chance, and then this starts to happen to where my ACTOR_BPs all vanish from the viewport. I use bspās because I can UV textures on geometry in a pinch, but itās Hard to work on something when you canāt even see it. so my actor bp doors are invisible unless I kick em. someone suggested I open up the bp and tick hidden then untick and re save. that works at times but if I move it it disappears again in the viewport. I shouldnāt have to do this every time so wtf. disapointed in UE5 again.
If some still really want to make something in ue5 right now, better to use 5.0.3ā¦
As this one do not have this major issue.
Sadly itās not the only issue with ue5, my main concern is in term of performances, also as I create something with heavy physx, honestly chaos give also bad physics performances and was getting better result with physx in ue4.
Guess will need some major ue5 releases before really consider it.
Can probably suit for some games projects, but in my case I still prefer to use ue4.
Many interesting new features in ue5 but will need to be patient I guess.
Indeed, this is a major bug for UE5, almost to the point where I regret upgrading to from ue4, since I use very few of the new features. (I still have old backups, but it has been so long since I upgraded, it would take me longer to redo my work again in UE4 than it would to just work around the problems I have with UE5)
. Have you find a solution?
then you need a hack to stop that command from running (which it does with BSP in the world, even with Build Lighting Only).