Reported in UDN: [Link Removed]

Reimporting a static mesh asset from an FBX file causes collision to disappear on spline meshes referencing the static mesh asset.

In investigating this in 4.27, I noticed that USplineMeshComponent::RecreateCollision() gets called twice during the FBX reimport process. And later in FKAggregateGeom::GetAggGeom() and FKConvexElem::DrawElemWire() although the ConvexElem appears to have the correct values, the underlying PhysX collision structure has been reset to default values. In 5.0, crash occurs within Chaos source.

Steps to Reproduce

Steps to Reproduce:

  1. Enable Show->Collision (Alt+C)
  2. Add a new Spline Mesh Actor to the scene
  3. Import the attached SplineMesh_Original.fbx to the content browser
  4. Assign SplineMesh_Original to the static mesh slot on the SplineMesh Actor and note the collision box
  5. Right click on SplineMesh_Original and click Reimport with New File, and select SplineMesh_Updated.fbx


Crash occurs upon reimport.


The collision box is updated to represent the collision for the spline mesh based on the reimported static mesh.

Have Comments or More Details?

There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-134573 in the post.

Login to Vote

Fix Commit18695068
Main Commit18695107
Release Commit18695068
CreatedNov 11, 2021
ResolvedJan 21, 2022
UpdatedJan 26, 2023