Decision Guide: Scheduler Stage Placement

Decision Guide: Scheduler Stage Placement

Boot

Use for one-time initialization dependent on runtime construction.

PreUpdate

Use for input sampling, event ingestion, and pre-sim prep.

FixedUpdate

Use for deterministic simulation:

• gameplay rules
• physics-like updates
• lockstep-critical logic

Keep synchronous.

Update

Use for variable-rate gameplay logic that need not be fixed-step strict.

LateUpdate

Use for ordering-dependent adjustments after main update.

Example: camera follow after player movement.

RenderPrep

Use for render data extraction and buffer preparation. Async allowed.

Render

Use for GPU submission/render execution. Async allowed.

PostRender

Use for cleanup, frame metrics, and deferred post effects. Async allowed.

Shutdown

Use for teardown and final flush.

Placement Rules

1. Deterministic simulation -> FixedUpdate.
2. IO/network/async -> render-allowed async stages or external queue.
3. Order-sensitive reads after writes -> later stage, not higher order in same stage by default.