Component & Core
This section covers the core runtime objects you work with every day: the actor and component that place a mesh in your world, the URealtimeMesh object that owns the data, and the LOD → section group → section hierarchy that organizes geometry. It also covers the everyday operations you drive on that model — configuring materials and LODs, pushing and updating geometry, and building collision.
If you haven’t yet, read Key Concepts first — this section assumes you’re comfortable with streams and stream builders, which are documented there and only linked (not re-explained) here. For the concrete mesh classes (URealtimeMeshSimple, URealtimeMeshProcedural, and the others), see Mesh Types.
- Structure — the object model end to end:
ARealtimeMeshActor,URealtimeMeshComponent, theURealtimeMesh→URealtimeMeshManaged→ leaf class hierarchy, theFRealtimeMeshdata layer, the LOD/section-group/section hierarchy, and the render-thread proxy mirror. - Section Groups & Sections — keys, configuration, draw types, stream ranges, and the auto-section-per-polygroup behavior that most meshes rely on.
- Materials — material slots on the mesh, how a section picks its slot, and how component-level material overrides interact.
- Levels of Detail — adding and configuring LODs and their per-LOD section groups.
- Updating Mesh Data — the full spectrum from a full re-push to in-place GPU fast paths, reading data back, and building off the game thread.
- Collision — simple analytic shapes, complex per-triangle collision, custom collision geometry, and async cooking.