# 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.
When you play a recording made with `--radius`, its snapshot is **painted automatically** for each viewer at the playback location and reverted when the actor despawns — no manual `/recap world apply` needed. The blocks are sent as client-side packets (one bulk change per 16×16×16 section), so the scenery shows up around the replay even in a different, empty world without touching server blocks. The manual `/recap world` commands below are for reviewing a snapshot on its own.
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## Capturing
A snapshot is captured automatically with every recording, out to `recording.capture-radius` (default 16 blocks). Override the radius per-recording with `--radius <n>` (or `-r <n>`):
```
/recap start arena_take @a --radius 32
```
`<n>` is the half-extent of the captured cube in blocks. Max 128; `0` disables it (player-only). The snapshot is centered on the recording player's location at start time. The same radius also tracks nearby mobs — see [[Recap/Server Owners/Features/Recording]].
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