Terrain Patcher

Terrain Patcher is a Subnautica and Below Zero library mod that allows modders and players to modify the game's terrain.

Installation

This mod requires BepInEx and Nautilus. The Nautilus dependency is optional but recommended.

You can download Terrain Patcher from the releases page (below the changelog), or from the Subnautica and Below Zero Submodica pages.

To install Terrain Patcher, just extract the zip file and place the TerrainPatcher folder into your BepInEx/plugins folder.

To install a .optoctreepatch file, place it in the TerrainPatcher/patches folder.

You can specify a custom load order for .optoctreepatch files by writing the file names (without the extensions) into the load-order.txt file.

Loading patch files can be enabled/disabled from the in-game config menu if Nautilus is installed.

Legacy Version

Some mods, such as Sea To Sea, may require using the legacy QModManager version of Terrain Patcher instead of the current BepInEx version. The legacy version can be downloaded from the releases page (below the changelog). Installation and usage instructions for the legacy version can be found in an older version of the repository. Please do not submit issues for bugs encountered on an old version of Terrain Patcher.

Library Usage

The following is for modders who want to use Terrain Patcher in your mod. Keep in mind that if your mod uses Terrain Patcher, anyone using your mod needs to have Terrain Patcher installed.

Patch Loading

There are two ways to load a terrain patch. The easiest way is to distribute your .optoctreepatch file alongside your mod. Terrain Patcher will find and load all .optoctreepatch files placed anywhere in the BepInEx/plugins folder or any subfolder.

Alternatively, you can add your .optoctreepatch file to your project as an embedded resource and add TerrainPatcher.dll as a reference. You can then use Assembly.GetManifestResourceStream (as demonstrated in ExampleMod.cs) to load the resource. If you pass this stream to TerrainRegistry.PatchTerrain, Terrain Patcher will apply your patch file. Below is an example of how to do this.

var asm = System.Reflection.Assembly.GetExecutingAssembly();
var patch = asm.GetManifestResourceStream("MyModName.my-file-name.optoctreepatch");
TerrainPatcher.TerrainRegistry.PatchTerrain("my-file-name", patch);

Dependency Registration

If your mod can function without Terrain Patcher (despite including terrain patches) then you don't need to add it as a dependency, and you can skip this section.

Regardless of which method you use to load patches, you'll need to add Terrain Patcher as a dependency of your mod (as shown in ExampleMod.cs). To do this, just add the [BepInDependency("Esper89.TerrainPatcher")] attribute to your mod's entry point, below the BepInPlugin attribute, as shown here:

[BepInPlugin("YourName.ExampleMod", "Example Mod", "0.0.0")]
[BepInDependency("Esper89.TerrainPatcher")]
internal class Mod : BaseUnityPlugin { /* ... */ }

Licensing

Terrain Patcher is licensed under the GNU AGPL, which says that derivative works must also be licensed under the GNU AGPL. If your mod directly interacts with Terrain Patcher (e.g. by referencing TerrainPatcher.dll and calling TerrainPatcher.TerrainRegistry.PatchTerrain), it might be considered a derivative work. To avoid any possible copyright issues, if your mod isn't licensed under the GNU AGPL, you should avoid referencing TerrainPatcher.dll or otherwise interacting with Terrain Patcher directly. Patches can still be loaded without referencing Terrain Patcher by distributing them alongside your mod.

Patch Format

The Subnautica Terrain Patch Format (the optoctreepatch format) is documented in Subnautica Terrain Patch Format.pdf. The format is designed to be as similar to the game's native terrain format as possible, while still allowing for proper patching of terrain. The patch format also allows as much data as necessary to be stored in one file, for easier distribution.

An example optoctreepatch file is included at example.optoctreepatch.

Patch files can be generated using Reef Editor, but any files conforming to the specification will work.

Terrain Patcher places patched batches in CompiledOctreesCache/patches, using the same naming system as the game does. These patched batches can be loaded by external tools, if they wish to support terrain patches.

Features

Modifying the game's terrain in a modular way.
Replacing some parts of a batch without replacing the whole batch.
As many world modifications as necessary can fit in one file.
No actual changes to game files; uses temporary files to store patched terrain.
Support for Subnautica and Below Zero.
Easily load patches without making a mod, or have more control by using a mod.
Custom load order.
Enable and disable patch loading in-game.
Cool rocks.

Planned Features

Extending the current edge of the world to allow for more terrain.
Patching biomes and entities.

Contributing

Contributions of any kind—issues, pull requests, feature requests—are all welcome. You can submit suggestions and bug reports as an issue, or code contributions as a pull request.

Building

To build Terrain Patcher, run msbuild in the project's root directory. This will build in debug mode, and the output will be placed in target/Debug. If you create a file in the project root called game-dirs.txt and input the paths to your Subnautica and/or Below Zero installations (one per line), the output of debug builds will be automatically installed into those game directories for easier testing.

To build Terrain Patcher in release mode, run msbuild -property:Configuration=Release. This will also create a dist.zip file in target for easy distribution.

License

This program is free software: you can redistribute it and/or modify it under the terms of version 3 of the GNU Affero General Public License as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.

Additional permission under GNU AGPL version 3 section 7

If you modify this Program, or any covered work, by linking or combining it with Subnautica (or a modified version of that program), containing parts covered by the terms of its license, the licensors of this Program grant you additional permission to convey the resulting work.

Esper89 / Subnautica-TerrainPatcher