InstantWorldMirror - Instant World Mirror

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Instant Sandbox - Explore Without Consequences

InstantWorldMirror provides Minecraft players with an instant sandbox testing ground. Using the Dimension Mirror, Heaven Mirror, or First Dream Mirror, you can create a mirror copy of the surrounding area or initial seed terrain at any location, freely explore, test, and experiment without worrying about any impact on the original world.

Core Use Cases

Mod Testing: Test new mod functionality and compatibility in the mirror world without risking your main save.
Redstone Debugging: Copy your redstone contraptions for repeated testing and debugging without teardown costs.
Adventure Scouting: Before entering a dangerous area (e.g., Ancient City, Twilight Forest), use a mirror to replicate the world, scout ahead safely, and then return to the main world to avoid deadly combat.
Building Design: Using the Heavenly Mirror, preview the architectural scheme in the mirror in creative mode. It can be directly replicated in the main world with the help of the WorldEdit Mod.
Resource & Boss Regeneration: Use the First Dream Mirror to solve the dilemma of depleted structures or unspawned bosses in multiplayer servers, allowing new players to re-challenge bosses and loot fresh resources.
Server Events / PVP: Provide safe, zero-cleanup activity spaces or temporal PVP arenas for players, with automatic cleanup after events.

Features

The Three Mystic Mirrors

Dimension Mirror (映界之镜)

Right-click any solid block to create an entry portal.
Inside the Mirror World, long-press the right button with the mirror to instantly teleport back to the entrance, or right-click any solid block to create a return portal anywhere.

Heaven Mirror (天堂之镜)

Shifts your game mode to Creative Mode upon entering for free testing and architectural prototyping.
Upon entry, your inventory is temporarily cleared (only retaining the Heaven Mirror). You cannot create return portals anywhere else—you must return via the entrance or by long-pressing right-click. Returning to the main world restores your original inventory and status instantly (like waking from a dream).

First Dream Mirror (初梦之镜)

Instantly generates a pristine, unedited parallel world based on your current world's seed.
Crucial Difference: Unlike the other two mirrors, any blocks or items obtained in this pristine world CAN be brought back to the main world!

Mirror World Mechanics

World Replication: Copies terrain within a configurable radius centered on the portal (default 10 chunks, configurable 1-32 chunks). Complete copying of blocks, block entities, biome data, and structure information.
Entity Isolation: Optional entity copying. Natural mob spawning is disabled by default to optimize performance, but can be enabled via commands or config.
Time & Weather Sync: Automatic synchronization of source world weather and time.
Death & Annihilation: Dying in the mirror world triggers an immediate respawn back in the main world. When all players leave, the mirror world automatically enters an annihilation and cleanup process.

Multiplayer Support

Supports up to 8 parallel mirror dimensions, allowing multiple players to use their own mirror worlds simultaneously.
Host & Guest Rules: Multiple players can enter the same mirror session through the same portal. However, visitors can only enter after the "Mirror Master" (the player who placed the mirror) enters first. When the Host returns to the main world, all visiting players are forcefully teleported back together.
Comprehensive permission system for server admins to control player access and item transfer rules.

Enchantment System

All mirrors can be enchanted via Enchanting Tables or Enchantment Books:

Efficiency (通用附魔 - 效率): Reduces the mirror's usage cooldown by 20% per level (Default max level reduces CD to 30s). Note: Mirrors have no cooldown in Creative Mode.
Permanence (通用附魔 - 永久): Press Shift + Right-Click inside a mirror world to permanently save or delete it. In the main world, Shift + Right-Click with the mirror allows you to teleport back to any saved permanent world, rename them, or destroy them completely.
Revival (初梦之镜专属 - 复苏): Exclusive to the First Dream Mirror. Unlocks the ecological seal of the parallel universe, enabling natural mob spawning and resource refreshing, turning it into a perfect parallel farming dimension.

Performance Optimization

Heightmap Scanning: Heightmap scanning technology skips air columns, significantly reducing unnecessary copying.
Section-Level Operations: Processes terrain via section-level operations instead of block-by-block processing.
Sequential Queue: Sequential queue processing to avoid server overload.
Smart Cleanup: Smart cleanup mechanism only processes modified chunks when players leave.

Future Outlook (What's Coming Next)

In upcoming versions, a new "Core Gadget" will be introduced, which can be combined with the three mirrors to craft advanced derivative tools:

Dimension Mirror Derivative: Used to mark a specific player. Right-click to teleport to them anytime, or even breach walls to enter their saved "Permanent Worlds".
Heaven Mirror Derivative: Used to mark a specific chest. Allows you to remotely transfer items into that chest wirelessly from any dimension or location.
First Dream Mirror Derivative: Projects primal power back into reality. When used in the Overworld, it forcefully reverts a small surrounding area back to its original seed topography (perfect for one-click fixing Creeper craters or regenerating mined-out veins).

Installation

Install NeoForge 1.21+
Download this mod JAR file
Place in .minecraft/mods folder
Launch the game

Crafting Recipe

Dimension Mirror
[Glass]    [Obsidian] [Glass]
[Obsidian] [Ender Pearl] [Obsidian]
[Glass]    [Obsidian] [Glass]

Heaven Mirror
[Glowstone]    [Redstone Dust] [Glowstone]
[Redstone Dust] [Ender Pearl] [Redstone Dust]
[Glowstone]    [Redstone Dust] [Glowstone]

First Dream Mirror
[Oak Spaling]    [Glass] [Oak Spaling]
[#minecraft:oak_logs] [Ender Pearl] [#minecraft:oak_logs]
[Oak Spaling]    [Glass] [Oak Spaling]

Commands

All commands start with /iwm:

Command	Description	Permission
`/iwm return`	Force return to source world	All players
`/iwm mob on/off/status`	Control mirror world mob spawning	OP (Level 2)
`/iwm allow <player>`	Allow player to use mirror feature	OP (Level 2)
`/iwm deny <player>`	Deny player from using mirror feature	OP (Level 2)
`/iwm itemtransfer <player> <true/false>`	Control player item transfer permission	OP (Level 2)
`/iwm status`	View dimension pool status and player info	OP (Level 2)
`/iwm forceclear <dimension>`	Force clear specified mirror dimension	OP (Level 3)
`/iwm purge`	Completely delete all mirror world saves (requires restart)	OP (Level 3)

Configuration

Config file located at config/instantworldmirror-common.toml

Dimension Pool Settings

Config	Default	Description
dimensionPoolSize	4	Mirror dimension pool size (1-8), determines max concurrent mirror sessions

World Copy Settings

Config	Default	Description
copyChunkRadius	10	Copy radius (chunks), total chunks = (radius*2+1)^2
copyChunksPerTick	2	Chunks copied per tick, higher = faster but may cause lag
cleanupChunksPerTick	4	Chunks cleaned per tick
edgeCleanupRadius	3	Extra radius for BFS edge cleanup scan

Portal Settings

Config	Default	Description
entryPortalLifetime	300	Entry portal duration (seconds), -1 for permanent
returnPortalLifetime	-1	Return portal duration (seconds), -1 for permanent
maxPortalLoadingTime	600	Maximum portal loading wait time (seconds)

Item and Mob Settings

Config	Default	Description
allowItemTransfer	false	Whether to allow players to bring items back by default
mirrorCooldown	300	Dimension Mirror cooldown (seconds), reduced by Efficiency
copyEntities	false	Whether to copy mob entities
copyDecorationEntities	true	Whether to copy decoration entities (paintings, item frames, etc.)
enableMobSpawning	false	Whether to allow natural mob spawning in mirror world

Environment Settings

Config	Default	Description
copyBiomes	true	Whether to copy biome data
copyStructures	true	Whether to copy structure data
copyHeightmaps	true	Whether to copy heightmap data

Server Limits

Config	Default	Description
maxMirrorWorldsPerPlayer	1	Maximum concurrent mirror sessions per player
staleSessionCleanupInterval	300	Stale session cleanup check interval (seconds)

Client Settings

Client config located at config/instantworldmirror-client.toml

Config	Default	Description
showCooldownHud	false	Show cooldown timer HUD in top-left corner

Important Notes

Automatic Cleanup: The mirror world automatically triggers an annihilation and cleanup process the moment all players leave, ready for its next use.
Item Retention: By default, items obtained in the Dimension Mirror and Heaven Mirror are NOT kept when returning. However, items obtained in the First Dream Mirror can be brought back entirely.
Stat & Buff Transfer: Character buffs, potion effects, and hunger levels gained from fighting mobs inside the mirrors WILL carry back to the main world.
No Nested Dimensions: You cannot build Nether or End portals inside the mirror world (strictly no nested space dimension looping!).
Admin Controls: Server admins have full control over player access permissions, dimension pools, and item transfer filters via commands and configuration.

Downloads

CurseForge - Mod download
GitHub - Source code

License

Apache License 2.0