Execution Flow

This page clarifies when each override runs and how a tick proceeds from input → simulation → physics → networking → view.

---

At a Glance

Client reconciliation (when a verified frame arrives):

Per-frame view update (client):

---

Startup & Registration

• PredictionManager.Awake

  • Registers instance per scene, sets Unity physics to script mode per provider, initializes pooling.

• OnEarlySpawn

  • Registers built‑in systems (Hierarchy, Players, Physics2D/3D, Time).

  • Registers scene PredictedIdentity components and assigns IDs/owners.

• PredictedIdentity.Setup

  • Called per identity with NetworkManager, PredictionManager, component ID, and owner.

  • On first spawn, calls LateAwake() once.

---

Per‑Tick (OnPreTick)

Order (server and client):

1. Mark simulation context

• isSimulating = true; on server, isVerified = true.

1. Input preparation

• Server: dequeues pending client input frames.

• For each identity: PrepareInput(isServer, isController, localTick, extrapolate)

  • On local controller: calls your GetFinalInput, SanitizeInput, writes to history.

  • On server for remotes: consumes QueueInput or optionally extrapolates.

1. Save pre‑simulation state

• SaveStateInHistory(localTick) for non‑event identities.

• Server: write initial frame payloads for state and inputs.

1. Simulation passes

• SimulateTick(localTick, delta) → your Simulate(...) implementation.

• LateSimulateTick(delta) → your LateSimulate(...) implementation.

• DoPhysicsPass() integrates Unity physics for the tick.

1. Save post‑simulation state

• SaveStateInHistory(localTick) for event‑handler identities.

• Server: write event streams and send frames to clients.

1. Post‑simulate & finish

• PostSimulate() per identity for any finalization.

• Finalize input/state per role (server vs client).

• Advance localTick.

• isSimulating = false.

---

Reconciliation (OnPostTick on client)

• Receive verified server frames and compute a target tick to reconcile to.

• Fire onStartingToRollback.

• Perform one of:

  • In‑place: RollbackToFrame(tick) → SimulateFrameInPlace(tick) → SimulateFrame(tick, save=true)

  • From previous frame: RollbackToFrame(frame, stateTick, inputTick) → SimulateFrame(verifiedTick, save=true)

• Mark isVerified = false, then replay to the latest local tick: ReplayToLatestTick(lastVerified + 1).

• SyncTransforms() and UpdateInterpolation(accumulateError: true) to smooth visual corrections.

• Fire onRollbackFinished.

View updates are not part of tick callbacks; see below.

---

View Update (Client)

• PredictionManager.Update or LateUpdate (based on UpdateViewMode):

  • For each identity: UpdateView(Time.unscaledDeltaTime)

  • Identities compute/advance viewState and render visuals.

• Ownership changes trigger OnViewOwnerChanged(old, new) inside UpdateView.

---

Override Cheat‑Sheet

• Spawning/Pooling

  • OnPreSetup() — before Setup on server‑side systems.

  • LateAwake() — once on fresh spawn; view‑only setup.

  • ResetState() — clear owner/IDs and interpolation; called when reusing pooled instances.

  • Destroyed() — cleanup on despawn/unregister.

• Input (on PredictedIdentity<INPUT, STATE>)

  • GetFinalInput(ref INPUT) — per tick, returns current frame input for the controller.

  • UpdateInput(ref INPUT) — per Unity frame; cache edge‑triggered inputs.

  • SanitizeInput(ref INPUT) — clamp/normalize before simulation.

  • ModifyExtrapolatedInput(ref INPUT) — strip non‑continuous inputs during remote extrapolation.

• Simulation

  • SimulationStart() — before first Simulate for this identity.

  • Simulate(...) — deterministic tick logic; mutate only STATE.

  • LateSimulate(...) — optional second pass each tick.

  • PostSimulate() — finalize per tick.

• State ↔ Unity

  • GetUnityState(ref STATE) — read Unity → state when needed.

  • SetUnityState(STATE) — apply rollback state → Unity.

• Reconciliation / History

  • SaveStateInHistory(tick) — invoked by manager before/after simulation.

  • Rollback(tick) — restore snapshot and apply to Unity.

  • ClearFuture(tick) — drop states beyond a given tick.

  • GetLatestUnityState() — manager asks identities to resync after replays.

• View & Interpolation

  • UpdateRollbackInterpolationState(delta, accumulateError) — accumulate/compute view corrections.

  • ResetInterpolation() — clear smoothing (e.g., teleports).

  • UpdateView(STATE viewState, STATE? verified) — render visuals.

  • OnViewOwnerChanged(old, new) — view‑only ownership transitions.