Hello !
I have an issue with HLOD generation that i was able to isolate on an empty project on UE 5.7.3 :
I’m using 2 HLOD partitions on 1 runtime grid in a World Partition Level.
The first HLOD is a “MergedMesh” type that reference the second has it’s parent. (nanited)
The Second HLOD is a “ApproximationMesh” type. (nanited also)
i’m having issue with the ApproximationMesh HLOD which have poor result from the baking : (see attachement)
From my actual project, i was able to deduce that the issue has to do with “CaptureScene” phase happening before the actual baking.
Using RenderDoc and the Command “r.RenderCaptureDraws x” i was able to look at the state of the geometry when capturing and it’s very low poly for some reason,
Kind of look like when we use the command “r.Nanite.ViewMeshLODBias.Offset” with extreme value that force all nanite mesh to have very low topology(I’ve also attached a screenshot from RenderDoc from another test, supposed to be a cluster of rock…)
HLODBakingResult.png(510 KB)
RenderDoc_Result.png(216 KB)
Steps to Reproduce
I Was able to repro using an empty project from latest 5.7.3 :
-create a Level With World Partition Enabled
-Setup 2 HLOD Layers in a runtime grid (first one using Merged Mesh and the second one using Approximation Mesh)
-MergedHLOD need to be nanited + HLOD Parent set to the other one
-ApproximationHLOD need to be nanited also (might be optional)
-create a cluster of StaticMeshActor somewhere in the level (good example is using a cliff/rock asset)
-Build HLOD and look at the resulting mesh
From the Repro Project :
-Open the “HLOD_TestNanite_Issue” level and look at the problematic HLOD from the “MergedHLOD_0_Nanite” HLOD Layers
Hello,
Thank you for reaching out.
I’ve been assigned this issue, and we will be looking into this HLOD generation for you.
Hello,
Thank you for reporting this. I can confirm this issue can be reproduced as described in the latest CL, and have opened a bug report:
https://issues.unrealengine.com/issue/UE\-366235
The tracker will be visible after it is approved internally at Epic Games and is publicly accessible.
If you have any further questions, please let us know.
