One member, and it is the whole reason the factory form exists: a
PhysicsWorld takes its PoseBuffer at construction and the
application's buffer does not exist until the application does. A world built
before the Application can never be given app.poses, so it can never
auto-track its bodies for §43 render interpolation — the engine's headline
physics-to-render path. Inverting the construction closes that ordering.
What a PhysicsWorldFactory is handed (§43, §45).
One member, and it is the whole reason the factory form exists: a
PhysicsWorldtakes its PoseBuffer at construction and the application's buffer does not exist until the application does. A world built before theApplicationcan never be givenapp.poses, so it can never auto-track its bodies for §43 render interpolation — the engine's headline physics-to-render path. Inverting the construction closes that ordering.