Minecraft Resource Pack

---
name: minecraft-resource-pack
description: "Create and debug Minecraft 26.x and 1.21.x resource packs, including pack metadata, textures, models, blockstates, item definitions, sounds, fonts, animations, and shaders. Use for client-side visual or audio assets without gameplay code."
---

# Minecraft Resource Pack Skill

## What Is a Resource Pack?

A resource pack is a folder (or `.zip`) that overrides or adds Minecraft's visual and
audio assets: textures, models, sounds, language files, and fonts. No Java or mod
loader is required for those vanilla assets.

### Routing Boundaries
- `Use when`: the deliverable is visual/audio assets (textures, models, sounds, fonts) in resource-pack format.
- `Do not use when`: the task requires gameplay logic or runtime behavior changes (use `minecraft-datapack`, `minecraft-plugin-dev`, or `minecraft-modding`).
- `Do not use when`: the task is server infrastructure/runtime administration (`minecraft-server-admin`).

---

## Pack Metadata

| Minecraft Version | Preferred `pack` metadata |
|-------------------|---------------------------|
| 1.21 / 1.21.1     | `pack_format: 34` |
| 1.21.2 / 1.21.3   | `pack_format: 42` |
| 1.21.4            | `pack_format: 46` |
| 1.21.5            | `pack_format: 55` |
| 1.21.6            | `pack_format: 63` |
| 1.21.7 / 1.21.8   | `pack_format: 64` |
| 1.21.9 / 1.21.10  | `min_format: [69, 0]`, `max_format: [69, 0]` |
| 1.21.11           | `min_format: [75, 0]`, `max_format: [75, 0]` |
| 26.1              | `min_format: [84, 0]`, `max_format: [84, 0]` |
| 26.2              | `min_format: [88, 0]`, `max_format: [88, 0]` |

Use legacy `pack_format` only for resource formats below 65 (through 1.21.8).
Resource format 65 and later require both `min_format` and `max_format`; use
`[major, minor]` for exact patch targeting, including `.0` such as `[84, 0]`.
An integer or `[major]` `min_format` means `[major, 0]`; an integer or
`[major]` `max_format` permits every minor version on that major line. Do not
write decimal JSON numbers. A legacy-only pack can use its integer
`pack_format` alone. A range whose `min_format` includes a legacy format needs
integer `pack_format` and `supported_formats`; do not include
`supported_formats` for a modern-only range.

---

## Directory Layout

```
my-pack/
├── pack.mcmeta
├── pack.png                   ← 64×64 icon (optional)
└── assets/
    └── minecraft/             ← override vanilla (or <namespace>/ for new packs)
        ├── models/
        │   ├── block/
        │   │   └── stone.json
        │   └── item/
        │       └── diamond_sword.json
        ├── items/              ← 1.21.4+ item model definitions
        │   └── diamond_sword.json
        ├── blockstates/
        │   └── stone.json
        ├── textures/
        │   ├── block/
        │   │   └── stone.png
        │   ├── item/
        │   │   └── diamond_sword.png
        │   ├── gui/
        │   │   └── sprites/
        │   │       └── my_sprite.png
        │   └── entity/
        │       └── zombie/
        │           └── zombie.png
        ├── sounds/
        │   └── custom/
        │       └── my_sound.ogg
        ├── sounds.json
        ├── font/
        │   └── default.json
        └── lang/
            └── en_us.json
```

Client-mod-specific files such as OptiFine CIT and Iris shader packs use their
own formats. Read [conditional assets](references/conditional-assets.md) before
adding them.

---

## `pack.mcmeta`

### 1.21.8 and earlier

```json
{
  "pack": {
    "pack_format": 64,
    "description": "My Custom Resource Pack v1.0"
  }
}
```

### 1.21.9 / 1.21.10

```json
{
  "pack": {
    "min_format": [69, 0],
    "max_format": [69, 0],
    "description": "My Custom Resource Pack v1.0"
  }
}
```

### 1.21.11

```json
{
  "pack": {
    "min_format": [75, 0],
    "max_format": [75, 0],
    "description": "My Custom Resource Pack v1.0"
  }
}
```

### 26.2

```json
{
  "pack": {
    "min_format": [88, 0],
    "max_format": [88, 0],
    "description": "My Custom Resource Pack v1.0"
  }
}
```

---

## Block Models

### `assets/minecraft/models/block/my_cube.json`
Full cube — all six faces use the same texture:
```json
{
  "parent": "minecraft:block/cube_all",
  "textures": {
    "all": "minecraft:block/stone"
  }
}
```

Column block (like logs):
```json
{
  "parent": "minecraft:block/cube_column",
  "textures": {
    "end": "mypack:block/my_pillar_top",
    "side": "mypack:block/my_pillar_side"
  }
}
```

Different sides:
```json
{
  "parent": "minecraft:block/cube",
  "textures": {
    "up":    "mypack:block/my_block_top",
    "down":  "mypack:block/my_block_bottom",
    "north": "mypack:block/my_block_side",
    "south": "mypack:block/my_block_side",
    "east":  "mypack:block/my_block_side",
    "west":  "mypack:block/my_block_side",
    "particle": "mypack:block/my_block_side"
  }
}
```

Cross model (flowers, plants):
```json
{
  "parent": "minecraft:block/cross",
  "textures": {
    "cross": "mypack:block/my_flower"
  }
}
```

### Custom geometry (elements)
```json
{
  "credit": "Custom model",
  "ambientocclusion": true,
  "textures": {
    "0": "mypack:block/panel",
    "particle": "mypack:block/panel"
  },
  "elements": [
    {
      "from": [0, 0, 7],
      "to": [16, 16, 9],
      "faces": {
        "north": { "texture": "#0", "uv": [0, 0, 16, 16] },
        "south": { "texture": "#0", "uv": [0, 0, 16, 16] }
      }
    }
  ],
  "display": {
    "thirdperson_righthand": {
      "rotation": [75, 45, 0],
      "translation": [0, 2.5, 0],
      "scale": [0.375, 0.375, 0.375]
    }
  }
}
```

> `from` and `to` are in 1/16th block units (0–16). `uv` is `[x1, y1, x2, y2]` in 0–16 units.

---

## Item Models

For **1.21.4 and later**, use item definitions in
`assets/<namespace>/items/`. For **1.21.3 and earlier**, use the legacy model
`overrides` array. Read [conditional assets](references/conditional-assets.md)
for the string-based current `custom_model_data` selector and the legacy numeric
predicate; their values are not interchangeable.

---

## Blockstate Definitions

### Simple block (no variants)
```json
{
  "variants": {
    "": { "model": "mypack:block/my_block" }
  }
}
```

### Facing block (4 rotations)
```json
{
  "variants": {
    "facing=north": { "model": "mypack:block/my_block" },
    "facing=south": { "model": "mypack:block/my_block",  "y": 180 },
    "facing=east":  { "model": "mypack:block/my_block",  "y": 90  },
    "facing=west":  { "model": "mypack:block/my_block",  "y": 270 }
  }
}
```

### Random texture (multipart)
```json
{
  "variants": {
    "": [
      { "model": "minecraft:block/grass_block",  "weight": 3 },
      { "model": "minecraft:block/grass_block_2" }
    ]
  }
}
```

### Multipart (slabs, fences, walls)
```json
{
  "multipart": [
    { "apply": { "model": "mypack:block/my_slab_bottom" }, "when": { "type": "bottom" } },
    { "apply": { "model": "mypack:block/my_slab_top"    }, "when": { "type": "top"    } },
    { "apply": { "model": "mypack:block/my_block"        }, "when": { "type": "double" } }
  ]
}
```

---

## Textures

- Format: **PNG**, RGBA (32-bit)
- Standard block/item size: **16×16 px**
- Textures can be larger (32×32, 64×64) — Minecraft scales them, but stick to powers of 2
- Animation requires height = N × width (e.g., 16×64 for 4 frames)
- Place block textures in `assets/<namespace>/textures/block/`
- Place item textures in `assets/<namespace>/textures/item/`
- All textures are referenced without the `.png` extension in JSON

### Animated texture MCMETA
`assets/minecraft/textures/block/fire_0.png.mcmeta`:
```json
{
  "animation": {
    "frametime": 2,
    "frames": [0, 1, 2, 3, 4, 5, 6, 7]
  }
}
```
If `frames` is omitted, all frames play sequentially. `frametime` is in game ticks (default 1).

### GUI sprites (1.20.2+)
Place sprites at `assets/minecraft/textures/gui/sprites/<category>/<name>.png`.
Reference them with `<category>/<name>` in code/JSON.

### 26.1 block-model texture entries
For 26.1, a block-model `textures` entry may remain a sprite string or use an
object. The object must have a string `sprite`; `force_translucent`, when set,
must be a boolean.

```json
{
  "textures": {
    "all": {
      "sprite": "mypack:block/frosted_panel",
      "force_translucent": true
    }
  }
}
```

Both forms identify a sprite without `.png`. Use `force_translucent` only when
the geometry must render in the translucent pass despite its sprite pixels.

---

## Sounds

An event's namespace comes from the namespace containing `sounds.json`; a
sound entry's `name` identifies the sound-file namespace. Sound files are Vorbis
`.ogg` under `assets/<namespace>/sounds/`. Read
[conditional assets](references/conditional-assets.md) for a correct event
example, aliases, sound-source selection, and replacement behavior.

---

## Language Files

`assets/minecraft/lang/en_us.json`:
```json
{
  "block.mypack.my_block": "My Custom Block",
  "item.mypack.my_item": "Magic Wand",
  "entity.mypack.my_mob": "Forest Guardian",
  "death.attack.mypack.laser": "%1$s was zapped by %2$s"
}
```

- Use the exact translation key format for your mod/datapack namespace
- File name is the locale code (e.g., `fr_fr.json`, `de_de.json`)
- Always provide `en_us.json` as the primary fallback

---

## Fonts

Read [conditional assets](references/conditional-assets.md) for bitmap provider
layout and private-use icon guidance.

---

## OptiFine and shaders

OptiFine CIT and Iris shader packs have client-mod-specific formats. Read
[conditional assets](references/conditional-assets.md) before adding either;
they are not portable vanilla resource-pack features.

---

## Installation

```bash
# Singleplayer: place in
~/.minecraft/resourcepacks/my-pack/
# or
~/.minecraft/resourcepacks/my-pack.zip

# Server-side (forces on clients):
# Set in server.properties:
resource-pack=https://example.com/my-pack.zip
resource-pack-sha1=<sha1 hash>
resource-pack-prompt={"text":"Required pack","color":"gold"}
```

---

## Common Issues

| Problem | Cause | Fix |
|---------|-------|-----|
| Model not showing | Wrong JSON path or syntax error | Check `assets/<namespace>/models/` path; validate JSON |
| Black/pink checkerboard | Texture path wrong or missing | Check `textures/` path, file extension not in JSON |
| Blockstate not applying | Wrong state property name | Use F3 to inspect block state; use `/data get block <x> <y> <z>` for block-entity NBT |
| Animation not working | Wrong MCMETA location | Must be same folder as texture, named `texture.png.mcmeta` |
| Custom sound not playing | Not in `sounds.json` | Register sound event in `sounds.json`, match namespace |
| Pack not loading | Wrong `pack_format` or `min_format` / `max_format` values | Update `pack.mcmeta` for the exact 1.21.x patch |

## Validator Script

Use the bundled validator script before shipping a resource-pack update:

Unbundled references to another namespace's models, textures, sounds, or fonts
are warnings requiring runtime verification with the dependency present. Missing
files in the current namespace fail; strict mode also fails unresolved warnings.

```bash
# Run from the installed skill directory (for example `.claude/skills/minecraft-resource-pack`):
./scripts/validate-resource-pack.sh --root /path/to/resource-pack

# Strict mode treats warnings as failures:
./scripts/validate-resource-pack.sh --root /path/to/resource-pack --strict
```

What it checks:
- JSON validity for `pack.mcmeta` and `assets/**/*.json`
- Legacy versus modern `pack.mcmeta` field shape, including integer, `[major]`, and `[major, minor]` versions
- Model/blockstate/font/sounds references resolve to real files
- Current `custom_model_data` select cases use strings; 26.1 texture objects use a string `sprite` and optional boolean `force_translucent`
- Same-namespace `type: "event"` sound aliases name an event in that `sounds.json`
- Every `*.png.mcmeta` has a matching `*.png`

The validator cannot resolve a sound event owned by another namespace, or prove
that a command or mod code invokes an event with the intended sound source.
Those cases warn and require an exact-client runtime check.

---

## References

- [Mojang: Java Edition 1.21.4](https://www.minecraft.net/en-us/article/minecraft-java-edition-1-21-4)
- [Mojang: Java Edition 1.21.9](https://www.minecraft.net/en-us/article/minecraft-java-edition-1-21-9)
- [Mojang: Java Edition 26.1](https://www.minecraft.net/en-us/article/minecraft-java-edition-26-1)
- [NeoForge 1.21.8: Sounds](https://docs.neoforged.net/docs/1.21.8/resources/client/sounds/)
- Misode's model viewer: https://misode.github.io/
- OptiFine CIT guide: https://optifine.readthedocs.io/cit.html