AGeneratedDynamicMeshActoris an Editor-only subclass ofADynamicMeshActorthat provides special support for dynamic procedural generation of meshes in the Editor, eg via Blueprints. Expensive procedural generation implemented via BP can potentially cause major problems in the Editor, in particular with interactive performance.AGeneratedDynamicMeshActorprovides special infrastructure for this use case. Essentially, instead of doing procedural generation in the Construction Script, a BP-implementable event OnRebuildGeneratedMesh is available, and doing the procedural mesh regeneration when that function fires will generally provide better in-Editor interactive performance.