About The Mod

Region History Viewer is a utility mod that lets you capture a snapshot of any region, come back to it later, then see any modifications made to that region in the time you were gone. By finding the difference between the taken snapshot and a new snapshot (or the current live world), the player can view what was Added, Removed or Changed.

This mod has a variety of uses, such as monitoring your base on a server to ensure no griefing, seeing what (perhaps untrustworthy) are building/removing on a server, monitoring farms, tracking down what broke in a redstone contraption, and many more!

Getting Started

To get started, craft or acquire a "Region Selector", made from 3 iron ingots, 1 redstone dust, and a quartz shard. This is the main tool that you will use to select your desired region.

Next, set your corners, left click to set one corner, right click to set the second corner. Then using the command:

/rhv snapshot <name of snapshot>

Add, remove or change (blockstate change, e.g. changing orientation of stairs), whatever you like.

Then run the command:

/rhv diff <name of snapshot>

The overlay will appear immediately, green boxes represent newly added blocks, red blocks are removed blocks, and orange blocks are blocks which blockstates have changed.

Additionally, right clicking the region selector in the air prints your current selection, shift + right clicking clears your selection. This selection stays even after death, or server logout, so you'll never lose your selected region.

Commands

Here's the full command list and their functions:

• Snapshot Region (/rhv snapshot <name of snapshot>): Captures your current selected bounds, saves it to the disk. Prints back the region size, how long it took and how much memory it uses. They are stored under <worldname>/region_history/, so they travel with world backups, and don't clutter your world file. This command will refuse if: the name of the snapshot is erroneous or the same as another snapshot, the region is over the size limit (8,388,608 blocks, approx 256x128x256), 
• Difference compared to Live World (/rhv diff <name of snapshot>): Compares the snapshot against the world as it is currently.
• Difference between Snapshots (/rhv diff <name of snapshot> <name of snapshot 2>): Compares two snapshots against each other, both snapshots must cover the same exact volume, or else it will refuse.
• List all Snapshots (/rhv list): Lists every stored snapshot in this world, showing size, dimension and time of capture.
• Snapshot Info (/rhv info <name of snapshot>): Shows full details for a specific snapshot, showing bounds, volume, dimension, player who captured it, time of capture, and size on disk.
• Delete Snapshot (/rhv delete <name of snapshot>): Removes a snapshot and its file
• Clear Overlay (/rhv clear): Hides the current overlay
• Display Limits (/rhv limits): Shows the server's set limits, including max region size, entry caps, and if deletion needs op.
• Selection Display (/rhv sel): Prints the dimensions of your current selection.

Overlay Modes

There are various overlay modes available, with keybinds to cycle them. Pressing K toggles the overlay, Shift + K cycles the overlay mode, O opens the snapshot browser, and Shift + O toggles the region boundaries. The various overlay modes include:

• Boxes: Translucent coloured boxes with outlines
• Outlines: Outlines only
• X-ray: Outlines through terrain
• Ghost: Renders the actual block models of what was there, coloured accordingly.

The region boundary draws a box around the whole snapshot bounds.

Snapshot Browser

Pressing O opens up the snapshot browser interface, showing your full stored snapshots history.

Left-clicking a snapshot sets it as your first reference, A, which should be your before. Right-clicking another region sets it as your comparison, B. Then Diff A > B compares these two snapshots. Diff vs Live World compares A against the current world, as it is right now. Shift-clicking a snapshot twice deletes it.

The browser also controls your display, such as overlay mode, region boundary, and category filters. You can toggle Added, Removed and Changed to hide and show categories.

Configuration

Client settings are editable, such as colours, opacity and behaviour. Right now they are only able to be changed by modifying files, however next update I'll add an easier config.

Server settings can be changed under config/region_history_viewer-server.toml, here you can customise the max region size, permissions and warning thresholds for large captures.

Known Bugs/Upcoming Features

• Better config system
• Sound effects when setting corners
• Bounds being able to be seen whenever, instead of only when difference is being found