Why does Niagara Skeletal Mesh DataInterface fail to bind?

Source Component is empty by default. Set it to the SkeletalMeshComponent on the actor spawning the emitter, either in Niagara setup or via SetSkeletalMeshDataInterface BP node at runtime.

Use a Default Mesh in DI settings?

Sets fallback for editor preview only. Runtime needs a real component reference; otherwise DI is null and emitter samples zero.

Niagara Component → Set Niagara Variable Object Asset on the User Parameter; or call SetSkeletalMeshDataInterfaceMesh BP node with the live skel mesh.

Fix: Niagara Skeletal Mesh DI Bind Fail

Quick answer: Set Source Component on the SkeletalMesh DI to the live SkelMeshComp. Use SetSkeletalMeshDataInterfaceMesh BP node at runtime.

Effect samples bone positions. In editor preview: works. In game: nothing emits, DI returns zeros.

The Fix

Niagara System:
  User Parameter: User.SkelMeshDI (Skeletal Mesh DI)
    Default Mesh:  PreviewMesh (editor only)

C++ on actor:
  NiagaraComponent->SetVariableObject(
      FName("User.SkelMeshDI"), MySkelMeshComponent);

// or BP
SetSkeletalMeshDataInterfaceMesh(
    NiagaraComponent, "User.SkelMeshDI", MySkelMeshComp)

Runtime binding fixes the editor-vs-runtime mismatch. Default Mesh is purely for design-time preview.

Verifying

Effect emits at bone positions. Without binding: spawns at zero or nothing.

“Bind at runtime. DI live. Bones sampled.”

Related Issues

For Niagara mesh on skel, see mesh on skel. For Niagara user parameter, see user parameter.

Bind runtime. Bones sampled.