CustomIslands Mapmaker Kit

Download this MANUALLY (the "Manual Download" button on this page). It is a Unity project, not a runtime mod - a mod manager would install it into the game where it does nothing.

Build your own islands for How to Fish and load them with the CustomIslands Loader mod. Sculpt terrain, dress it with the game's own props, place working shops and NPCs, and ship it as two files anyone can install.

This kit contains zero game assets. It is tools only. Everything from the game - props, materials, islands - is imported from your own installed copy during setup. What you build and publish is your business; the kit stays clean.

What you need

• Windows PC with about 20 GB free disk space (Unity ~8 GB, the ripped game files ~5 GB, working room for the rest)
• How to Fish installed (Steam)
• Everything else is free and covered below

Part 1 - Install Unity (one time)

1. Download Unity Hub from unity.com/download and install it. Create a free Unity account when it asks (choose the free Personal licence).

2. Install the exact editor version the game uses - 6000.4.4f1. Unity Hub does not list it, so use this link (it opens Unity Hub and installs the right version):

   unityhub://6000.4.4f1/360f97ecca93

   Paste it into your browser's address bar if clicking does nothing. No optional modules are needed - untick everything to save space.

3. Wait for the install to finish (several GB).

Part 2 - Open the kit (one time)

1. Unzip this kit anywhere you like, e.g. Documents\HTF Mapmaker Kit.
2. In Unity Hub, Projects tab, click the arrow next to "New project" and choose "Add project from disk" - do NOT create a new project.
3. Select the unzipped folder (the one containing Assets, Packages and ProjectSettings).
4. Open it. The first import takes a few minutes. When it finishes you should see a "How to Fish" menu in Unity's menu bar - that menu is the whole kit.

Part 3 - Set up from your game copy (one time)

1. Download AssetRipper (free) from github.com/AssetRipper/AssetRipper/releases
   • grab AssetRipper_win_x64.zip, and unzip it anywhere.
2. In Unity: How to Fish > Set up from your game copy.
3. Point the window at the AssetRipper exe you just unzipped, check the game folder it found, pick an empty folder to rip into, and press "Open AssetRipper and watch for the rip".
4. AssetRipper opens as a browser tab. In it: File > Open Folder (the game path is already on your clipboard - paste it), wait for the game to load, then Export > Export All Files into your chosen folder, using the blue Export Unity Project button.
5. The kit watches that folder and offers "Import now?" the moment the export finishes. Accept - one progress bar later everything is imported, repaired and armed (the finish dialog shows the counts: terrain stamps, props gathered).

That is the whole setup. From here on it is just mapmaking.

Making a map

1. How to Fish > New map (blank), or New map from any island to start from a real island's terrain.
2. Open How to Fish > Map Creator - sculpt the ground, stamp real island terrain with the Stamp brush.
3. Dress it with How to Fish > Prop brush - the entire prop library from every island. Props placed with a "Place as" choice become real gameplay in game: a (Purchasable) becomes a working shop stand with a price tag, a (Pickup) becomes a real item lying there.
4. The rules the loader depends on:
   • everything under a root object called IslandHolder
   • a PlayerSpawnPoint and a BoatSpawnPoint marker
   • colliders on anything you stand on (Maintenance > Make colliders match their meshes does it)
5. Paint the ground. The Map Creator has Grass and Sand brushes with a colour palette for the grass. One warning worth having up front: grass looks wrong in the Unity viewport and correct in game. Judge it in game and do not chase it in the editor.
6. Settle everything. Palms spawn a fraction above the ground - the Sink palms slider lowers every palm at once, and pressing it again sinks them further (Ctrl+Z puts them back). Drop everything onto the ground finds anything left floating or buried and seats it on the surface.
7. Sanity-check with Maintenance > Check the map.
8. Test it: How to Fish > Build and install into the game, then just start the game.

Playing through Thunderstore Mod Manager or r2modman?

Mod managers keep their OWN mods folder in AppData and launch the game against that - not against the game's Steam folder. Since 1.0.2 the build button installs your map into every install it finds: the Steam game folder AND every mod manager profile, and the build popup lists exactly where it went. So it just works either way you launch.

One catch it will warn you about: if you also have an island package installed (like BetterIslands) that claims the same island as your map, the game may load either one. Disable that package in the mod manager while testing your own map.

Your map is two files

yourmap.bundle (built by the kit) and yourmap.json beside it - the kit writes both when you build:

{
  "name": "Coral Cove",
  "author": "you",
  "replacesIsland": 2,
  "casinoFromIsland": -1
}

replacesIsland is part of your map's design, not a preference. Your map stands in for one of the game's five islands (0 to 4) and borrows that island's NPCs, shops and progression - a custom island 2 can only ever replace island 2. Choose it when you start building, declare it here, and the loader enforces it.

Replace, not add. The game's world is exactly five island slots - only one island exists at a time, and travelling swaps which one is loaded. There is no ocean where a sixth island could float, so a custom island always TAKES THE PLACE of one of the five. Adding extra islands is not possible with this kit.

Want an island that borrows nothing? Players can set ImportGameplay = false in the loader's config and your map arrives with no NPCs or shops at all - pure scenery plus whatever you placed.

casinoFromIsland: islands 3 and 4 have casinos - set 3 or 4 to borrow one onto your map (place it with How to Fish > Put a casino here).

Skies are not the map's business: players running Living Skies get the full day-night cycle and storms over every island, yours included.

Recovering a map you have already released

A published map is its own backup. If you lose the Unity scene, the .bundle you shipped can be turned back into an editable island:

1. Rip the bundle with AssetRipper, the same way as the game itself.
2. How to Fish > Import a ripped map.
3. Adopt the terrain so the Map Creator can sculpt it again.
4. Relink the props to the kit's library, then Seat them on the ground.

You get a working scene back rather than starting over.

Sharing your map

Players drop both files into BepInEx/plugins/HTFMaps/. Or publish on Thunderstore: zip them inside a folder named HTFMaps with your icon, README and manifest, and add CustomIslandsLoader as a dependency - mod-manager installs then just work (BetterIslands is the template to copy).

Co-op: everyone in a lobby needs the same maps installed.

Getting the original island back: a custom map only stands in while its files are installed - nothing is permanently changed and saves are untouched. Remove the map's two files from HTFMaps (or toggle the island pack off in the mod manager) and the next launch is pure vanilla.

Updating from an older kit

Older kits only installed builds into the game's Steam folder - if you play through Thunderstore Mod Manager, your map never appeared in game, and the map's author field defaulted to your Windows username. Your maps and scenes are fine; only the editor tools need swapping. Two ways:

The quick swap (keeps your project exactly as it is):

1. Download the new kit zip from Thunderstore (Manual Download).
2. Close Unity.
3. In the zip, open the Assets/Editor folder. Copy everything in it into YOUR kit project's Assets/Editor folder, replacing when asked.
4. Reopen your project. Done - the build button now installs everywhere and the Map Creator has an Author field. Set your name there once, then Build and install each of your maps again so their .json files carry your name instead of your PC username.

The fresh start (if your project is in a bad state anyway):

1. Unzip the new kit somewhere new and set it up as in Part 2 and 3.
2. Copy your old project's Assets/GameIslands folder (your scenes) into the new project's Assets folder.
3. Open your scene and carry on.

If something goes wrong

• The How to Fish > Maintenance menu holds every builder and repair tool individually - setup runs them all automatically, so you only need them for recovery.
• Maintenance > Diagnose the open scene explains most oddities.
• Red errors on first open usually mean the wrong Unity version - it must be exactly 6000.4.4f1.
• Built a map but nothing changes in game? Check the build popup's list of install locations - and make sure no other island package claims the same island (disable it in the mod manager while testing).

More from Yoxi

• CustomIslands Loader - the mod that runs custom islands (required for any island pack)
• BetterIslands - an island pack: three of the five islands rebuilt by hand
• Better Oceans - a real sea: surf on the shore, glitter on the chop, lit by the world
• Torch - a real torch item: fire in your fist, light and moving shadows
• Living Skies - day-night cycle PLUS storms, rain, lightning and thunder
• HTF Day and Night - the calm-sky day-night cycle on its own

Kit and loader built by Yoxi.

Changelog

1.0.3

• Sink palms - a slider that lowers every palm on the island, because they spawn a fraction above the ground by default. Press again to sink them further, Ctrl+Z puts them back.
• Grass and Sand brushes - paint ground cover straight onto the terrain, with a colour palette for the grass. Note that grass looks wrong in the Unity viewport and correct in game: judge it in game.
• Drop everything onto the ground - finds every prop left floating or buried and seats it on the surface.
• Recovering an island from a shipped bundle. A map you have released is its own backup: Import a ripped map, adopt its terrain, relink its props and seat them, and you have an editable island again.
• Every tool refreshed to the current versions.

1.0.2

• Fix: builds now install into Thunderstore Mod Manager / r2modman profiles too, not just the game's Steam folder. If you play through a mod manager, your map now actually shows up in game. The build popup lists every place it installed to.
• Fix: the map author no longer defaults to your Windows username. Set your name once in the new Author field in the Map Creator. Rebuild your maps to refresh their .json files.
• The build warns when an installed island package (e.g. BetterIslands) claims the same island as your map.
• README: how to update an existing kit project (quick swap of Assets/Editor), and a mod-manager section.

1.0.1

• Clearer docs: maps replace one of the five islands, never add a sixth - and how to make an island that borrows no NPCs at all (ImportGameplay = false).

1.0.0

First release.

• A complete Unity mapmaking project for How to Fish: terrain sculpting, a stamp brush with every island's terrain, a prop brush with the whole prop library, working shop stands and pickups by naming, one-button build-and-install.
• One-button setup: the kit launches AssetRipper against YOUR copy of the game, watches the export, then imports, repairs and arms everything automatically.
• Ships zero game assets - tools only.