CustomIslands MapmakerKit

v1.0.3·Updated 2026-08-31

Build your own How to Fish islands in Unity: sculpt, dress with the game's props, place working shops, ship as two files. Tools only, no game assets. DOWNLOAD MANUALLY - this is a Unity project, not a

About this mod Author’s original text

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)

  • Download Unity Hub from

unity.com/download and install it.

Create a free Unity account when it asks (choose the free Personal

licence).

  • 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.

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

Part 2 - Open the kit (one time)

  • Unzip this kit anywhere you like, e.g. Documents\HTF Mapmaker Kit.
  • In Unity Hub, Projects tab, click the arrow next to "New project"

and choose "Add project from disk" - do NOT create a new project.

  • Select the unzipped folder (the one containing Assets, Packages

and ProjectSettings).

  • 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)

  • Download AssetRipper (free) from

github.com/AssetRipper/AssetRipper/releases

  • grab AssetRipper_win_x64.zip, and unzip it anywhere.
  • In Unity: How to Fish > Set up from your game copy.
  • 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".

  • 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.

  • 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

  • How to Fish > New map (blank), or New map from any island to

start from a real island's terrain.

  • Open How to Fish > Map Creator - sculpt the ground, stamp real

island terrain with the Stamp brush.

  • 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.

  • 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)

  • 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.

  • Settle everything. Palms spawn a fraction above the ground - the

Sink palms slider lowers every palm at once, and pressing it again

sinks them

Install & use Install: follow the bundled instructions

  1. Unzip the archive from playbuff and read the bundled readme / instructions first.
  2. Most mods rely on the game's mod loader — the usual route is a community mod manager (such as r2modman): pick this game, install, and it handles the loader and dependencies.
  3. For a manual install, put the mod files into the matching Mod / plugins folder inside the game directory.
  4. Launch the game to confirm it loaded; mods with listed dependencies need those installed as well.

Install locations vary a lot between mods — the bundled readme is the most reliable guide.

File & checksum

Filename
CustomIslands_MapmakerKit-1.0.3.zip
File size
252.0 KiB