#Snapshot

#Purpose

The Snapshot section saves or loads the current simulation state as a .golt file. Snapshots are restartable state, not rendered media. Use downloads for PNG, MP4, metrics, and recorded-frame exports.

#Controls

• Progress status:
  Shows snapshot save/load progress. Large snapshots can show determinate progress while streaming or decompressing grid data.
• Save:
  Requests a snapshot from the engine, serializes it in a snapshot worker, and downloads a .golt file.
• Load:
  Opens a file picker for .golt files and loads the selected snapshot.

Both Save and Load are disabled while running, downloading, stepping, saving, or loading.

#Snapshot Contents

A .golt snapshot contains:

• Grid columns and rows.
• Grid topology.
• Virtual boundary tribe.
• Random seed for probabilistic rules.
• Generation counter.
• Packed grid data.
• Grid packing metadata.
• Tribe IDs and colors, using the Tribe JSON shape.
• Rules, using the Rule JSON shape.

Boundary cells for bounded topology are not stored in the grid payload. The snapshot stores only the selected boundary tribe; off-grid neighbor reads reconstruct the virtual boundary behavior after loading.

For the low-level file layout and how to parse it, see Snapshot format.

Loading a snapshot rebuilds the engine if grid, topology, tribes, rules, random seed, or packing need new GPU resources.