Keep Across Scenes vs. Remember Home Scene

Remember Home Scene vs. Keep Across Scenes

Crystal Save provides two different persistence modes for controlling how SaveablePrefab instances behave across scene changes: Remember Home Scene and Keep Across Scenes. While both impact object restoration, they serve very different purposes and have distinct performance characteristics.

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Remember Home Scene

What It Does

• Ties the SaveablePrefab to a specific scene where it was originally spawned.

• Crystal Save stores:

  • The home scene name.

  • Transform state (position, rotation, scale).

  • Active state and all saved component data.

• On load:

  • The prefab is only restored when you are in its home scene.

  • It is not present in other scenes until you return.

Typical Use Case

• Scene-specific pickups, interactables, or NPCs.

• Props or enemies that only exist in one map/location.

• Avoids keeping unnecessary objects alive when they aren’t relevant.

Limitations

• Will not persist into other scenes without being destroyed and reloaded.

• Switching scenes destroys the object until its home scene is reloaded.

• Cannot be used for SaveableComponent-only objects — see important note below.

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Keep Across Scenes

What It Does

• Marks a SaveablePrefab to stay alive across scene loads.

• Uses Unity’s DontDestroyOnLoad internally to keep the same instance alive between scenes.

• Saves and restores component data for the same instance rather than re-instantiating.

Typical Use Case

• Player characters.

• Global managers, persistent UI, or inventory systems.

• Any object that must keep its runtime state seamlessly.

Performance Implications

Pros

• No re-instantiation or re-serialization when switching scenes.

• Keeps all runtime state exactly as it was.

Cons

• Stays in memory for the entire session — even if not in use.

• More persistent objects = more cumulative memory usage.

• Always serialized into save files, increasing save size.

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Side-by-Side Comparison

Feature / Behavior	Remember Home Scene	Keep Across Scenes
Scene Boundaries	Bound to original scene only	Exists in all scenes
Persistence Method	Destroyed/re-spawned on scene load	DontDestroyOnLoad keeps same instance alive
Memory Usage	Low – object exists only in its home scene	Higher – object always in memory
Save File Size Impact	Minimal if unused scenes are skipped	Always included in save data
When to Use	Scene-specific world objects	Global objects that must never reset
Restoration Timing	On entering its home scene	Never destroyed, state carried over directly
Performance Impact	Scene load includes instantiation & restoration	Persistent memory cost, no re-instantiation

Lifecycle Flow Diagram

Below is an internal flow diagram showing how Crystal Save treats these modes:

Memory & Performance Impact Chart

Mode	Runtime Memory Usage	CPU Cost on Scene Load	Save File Size	Load Speed	Best Use Case
Remember Home Scene	Low – only loaded in home scene	Medium – must re-instantiate & restore data	Small – only saved when in use	Slower – due to instantiation	Scene-specific world objects
Keep Across Scenes	High – always in memory	Low – no instantiation on scene change	Large – always included in saves	Faster – skips object creation	Player, managers, persistent UI

Choosing the Right Option

• Use Remember Home Scene for:

  • Location-bound props, interactables, or enemies.

  • Situations where freeing memory between scenes is important.

• Use Keep Across Scenes for:

  • Core systems, player characters, or UI that must never reset.

  • Situations where continuity between scenes matters more than memory savings.