# World Snapshots
A world snapshot is a frozen cube of blocks captured at the moment a recording starts. On playback you can re-apply the snapshot for individual viewers so they see the world as it was when the clip was filmed — useful for replaying a destroyed arena, a built-up castle, a cleared mine.
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## Capturing
Add the `--world <radius>` (or `-w <radius>`) flag to `/recap start`:
```
/recap start arena_take @a -w 32
```
`<radius>` is the half-extent of the captured cube in blocks. Max 128. The snapshot is centered on the recording player's location at start time.
The snapshot saves to `plugins/Recap/recordings/<recording>.rwsnap` (separate from the `.recap` motion file).
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## Storage format
`.rwsnap` files use a GZIP-compressed binary format with a block-state palette and a packed index array. A 32-radius cube (~262k blocks) typically compresses to a few hundred KiB.
The palette is variable-width: 1 byte per index when the palette has ≤256 distinct states, 2 bytes when larger. Air-dominant cubes (most of them) compress to near-nothing.
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## Applying
```
/recap world apply <recording_name>
```
Applies the snapshot to the calling viewer's world. Block changes are sent as packets — they're **per-viewer**, not server-side. Other players see the world unchanged.
Each viewer's pre-paint state is captured into an undo log so it can be restored later.
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## Restoring
```
/recap world restore
```
Restores the calling viewer to their pre-snapshot blocks. Server world state never changed; only this viewer's client view did.
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## Use cases
- **PvP arena replays** — capture the destroyed map state as part of the recording, replay viewers' clients see the same crater patterns.
- **Build cinematic** — capture a completed structure, demolish it server-side, viewers can still see the original by applying the snapshot.
- **Mine reset preview** — show players what a regenerated zone will look like before committing the server-side change.
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## See Also
- [[Recap/Server Owners/Features/Recording]] — main recording flow
- [[Recap/Server Owners/Commands]] — `/recap world …` subcommands