Runtime FBX Import for Unreal Engine - Documentation

What Is an FBX Mesh Actor?

When an FBX is imported with Spawn FBX Actor enabled, the plugin creates one AFBXMeshActor (or your own subclass) in the world. This actor holds all generated ProceduralMeshComponents organized under a node hierarchy that mirrors the FBX scene structure.

You can query, select, and modify this actor using Blueprint nodes at runtime.

Selection and Hover

Call these on the FBX Import Manager actor reference (not on the mesh actor directly):

Node	What it does
Select Actor	Marks an FBX Mesh Actor as selected and triggers `On Actor Selected` on that actor, where you can implement a highlight or outline effect.
Hover At Actor	Triggers hover highlight on the actor and a specific component under the cursor.
Reset Hovered Actor	Clears the hover state.
Reset Actor Selection	Deselects all currently selected actors and components.

Call these on the FBX Mesh Actor reference itself to work at the sub-component level:

Node	What it does
Select Component	Selects an individual mesh section (e.g. from a hit result). Triggers `On Component Selected`. Pass `bDeselectRest = true` to auto-clear previous selection.
Deselect Current Components	Clears the current component selection.
Select Component From Mesh Node	Select a component by passing its `UMeshNode` reference instead of a hit component.

Querying Nodes

Node	Returns
Get Root Nodes	Array of all top-level `UMeshNode` objects in the hierarchy
Get Mesh Node From Component	The `UMeshNode` associated with a given `ProceduralMeshComponent`
Get Skeletal Mesh Nodes	Array of all `USkeletalMeshNode` objects — the bone-based meshes in this actor

ℹ️ Mesh Node hierarchy: UMeshNode is the base class. Geometry meshes are UMeshNode_Geometry. Collision meshes are UMeshNode_Collision. Skeletal meshes are USkeletalMeshNode (extends Geometry). Light nodes are URuntimeLightNode.

Changing Materials at Runtime

Call these on the FBX Mesh Actor reference:

Node	Parameters	What it does
Update Section Material	Section ID, Material Interface, Mesh Component	Replaces the material on a specific section by index
Update Texture Parameter	Section ID, Parameter Name, Texture, Mesh Component	Swaps a texture inside a dynamic material by parameter name
Update Scalar Parameter	Section ID, Parameter Name, Float, Mesh Component	Changes a float property (e.g. roughness, metallic) inside a material
Update Vector Parameter	Section ID, Parameter Name, LinearColor, Mesh Component	Changes a color or vector value (e.g. tint) inside a material

💡 Section ID: Each material slot in the imported mesh corresponds to a section index starting from 0. If your FBX mesh has 3 materials, Section IDs are 0, 1, and 2.

Blueprint nodes: Update Section Color Parameter, Update Section Texture, and Update Section Material wired to custom events

Implementable Events on the FBX Mesh Actor

Override these in your own Blueprint subclass of AFBXMeshActor to add custom feedback:

Event	When it fires
On Actor Selected	When this actor is selected via `Select Actor`
On Actor Selection Reset	When selection is cleared
On Component Hovered	When the cursor moves over a specific mesh component
On Component Selected	When a specific mesh section is selected
On Section Received	Called with full section data, material info, and texture info — useful for populating a properties panel