Custom follower forms

A follower form is a set of per-slot overrides layered over one of the game's own follower base skins. Each override names a slot on the follower skeleton and supplies an image, a placement and a list of colour choices. Forms live in BepInEx/plugins/CultTweaker/FollowerSkins, one folder per skin, with a folder per variant inside it.

Preparing followerSlots.json

followerSlots.json is an important part of building skins: it provides the SlotIndex and PartName for each part you want to override.

Every major update of Cult of the Lamb may change the format of follower forms, which means skins have to be updated to match the new format. To get the latest slot list for an update, enable the DumpFollowerSpineAtlas config inside BepInEx/config/InfernoDragon0.cotl.CustomSpineLoader.cfg. This generates followerSlots.json for that particular update, written to CultTweaker/followerSlots.json.

Woolhaven's followerSlots.json is provided in the template's instruction folder.

Folder layout

The provided template folder, ruffTemplateSkin, shows the folder structure of a custom follower form, including how to set up the base and variant forms. Put the folder into the CultTweaker plugin folder so that it reads CultTweaker > FollowerSkins > ruffTemplateSkins, and the plugin will load the forms into the game.

| CultTweaker.dll
| FollowerSkins
    | YourSkinName
        | base
            | head.png
            | config.json
        | variant
            | head.png
            | config.json

Inside each form folder you need:

• a config.json file
• any number of image files for your parts

The image files should be separated as single sprites, not a spritesheet. They can have any name, as long as you name them in the config.json.

config.json

Create a JSON file with partConfigs as the main key. Only SlotIndex and PartName are required; everything else is optional.

{
    "overrideBaseSkin": "Cat",
    "partConfigs": {
        "part2": {
            "SlotIndex": 89,
            "PartName": "HEAD_SKIN_BTM",
            "scaleX": 1.0,
            "scaleY": 1.0,
            "rotation": -90.0,
            "offsetX": 0.0,
            "offsetY": 0.0,
            "colorChoices": ["#FF0000"],
        },
        "part1back": {
            "SlotIndex": 89,
            "PartName": "HEAD_SKIN_BTM_BACK",
            "colorChoices": ["#FF0000"]
        },
        "part2top": {
            "SlotIndex": 91,
            "PartName": "HEAD_SKIN_TOP",
            "colorChoices": ["#FF0000"]
        },
        "part1backtop": {
            "SlotIndex": 91,
            "PartName": "HEAD_SKIN_TOP_BACK",
            "colorChoices": ["#FF0000"]
        },
        "color_leg_left": {
            "SlotIndex": 48,
            "PartName": "LEG_LEFT_SKIN",
            "colorChoices": ["#0000FF"],
        },
        "color_leg_right": {
            "SlotIndex": 49,
            "PartName": "LEG_RIGHT_SKIN",
            "colorChoices": ["#0000FF"]
        }
    }
}

In this example part2.png is applied to slot 89 at HEAD_SKIN_BTM, and part1back.png is applied to slot 89 at HEAD_SKIN_BTM_BACK.

Top-level fields

Each key in partConfigs (such as part2) can be any name. If it matches an image file name in the same folder, that image is used for the SlotIndex / PartName specified in it. Each partConfig is named after the image file without the extension: part2.png = part2.

The image file is optional. A key with no image lets you override just the slot's colours, like color_leg_left above.

Part fields

Field names are matched case-insensitively, which is why the example above mixes SlotIndex with scaleX.

The follower skin editor (F8)

Press F8 anywhere in the game except the title screen. The editor edits the same FollowerSkins/ folders the mod loads, so there is no separate project format.

The left panel picks which skin and variant you are editing (and starts new ones), the colour set, the base skin every layer sits on (Cat, Dog and so on), an outfit for the preview to wear (just for looking - it is not part of the skin), the animation the preview plays, and the list of layers: pick a slot to override it, then click a layer to work on it.

The right panel is that layer - its slot, the image covering it, whether it is hidden, its placement, and its colour for the set you are editing.

Names are written as skin/variant, so one prompt makes either a new variant of a skin you have or a whole new skin. Ctrl+S saves, and saving makes the skin wearable straight away: it rebuilds the skin for the game, which pauses for a moment. Drop PNGs into the variant's folder and they show up in the image picker.

Adding a colour set is an entry at the top of the Colour set list, like new skins and new layers.

Custom follower forms can only be selected during indoctrination. For the rest of follower customisation - colour (R, G, B, A) and what they wear - you must toggle Enable Customization for the costume override to take effect.

Migrating from JSONLoader

• Instead of a spritesheet with all of the sprites in one image, you must separate them into single sprites.
• The JSON config file differs in the following ways:
  • The JSON file should be named config.json, and be in the folder together with the skin.
  • colors and overrides are both combined as partConfig.
  • name is now partName and slotIndex.
  • rect is not needed; it will automatically use the sprite size.

The follower skin builder does this conversion for you: import a JSONLoader skin and it produces the CultTweaker part configs, then previews them live.

Known issue