Volumes with infinite or missing faces when importing .fbx file

UDN Description:

We are having issues with the "Create Blocking Volume" tool on StaticMeshActors. When we create a convex blocking volume (any convex, rough or heavy), we often have volumes that have infinite faces, and sometimes missing faces. I was able to reproduce this issue in ue 5.4.

We can see that the volume has an infinite (or very large) face and if we hide the static mesh, we can see that the volume is missing the top and back face (one edge is missing).

We have inspected the model and everything looks ok. It seems something is broken in the CREATE_BV_CONVEXVOLUME code in UnrealEdSrv.cpp. The issue can sometimes happen using a regular cube from Unreal, but not 100%.

Another related issue I'm observing: if you rotate the asset before creating the blocking volume, the volume does not fit very tightly with the asset.

Repro steps with the included static mesh: SM_TestStaticMesh.FBX:

1. Import the fbx file.
2. Create a new level and drag n drop the SM_TestStaticMesh static mesh into the scene.
3. Select the static mesh actor and in the details panel, select Static Mesh > Advanced > Create Blocking Volume > Rough Convex Volume.
4. Observe that the blocking volume is broken: