Create an actor in the editor viewport. Each actor will have a specific ID and a label that is displayed above it, with a specific color. The ID values are things like: ActorID_Train_Base, ActorID_Train_GroundTruth, ActorID_Test_Base, ActorID_Test_MLDeformed and ActorID_Test_GroundTruth. You can find the ID values of those inside the FMLDeformerEditorActor.h file.