npm package: @mattzh72/lodestone
Description: Rendering and core utilities for programmatic Minecraft scenes (Three.js + WebGL)
Author: Matthew Zhou
Latest version: 0.4.0

# Lodestone

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[![MIT License](https://img.shields.io/badge/license-MIT-green?style=flat-square)](LICENSE)

A TypeScript library for rendering Minecraft structures in the browser or headless environments.

![Demo](assets/demo.gif)

## Why Lodestone?

Build interactive Minecraft structure viewers, schematic editors, world previews, or any web-based Minecraft visualization tool. Lodestone handles the complexity of parsing Minecraft's block models, assembling meshes, and rendering them efficiently with Three.js—so you can focus on your application.

## Features

- **Litematic file support** — Load and render `.litematic` schematic files (Litematica mod format)
- **Flexible rendering** — `ThreeStructureRenderer` provides full-featured Three.js rendering
- **Resource pack system** — Works with the built-in default pack or your own custom resource packs
- **Advanced rendering** — Chunked meshing with occlusion culling, transparency sorting, and emissive block support
- **Universal runtime** — Runs in browsers and headless environments with WebGL
- **Full type safety** — Written in TypeScript with complete type definitions

## Installation

```bash
npm install @mattzh72/lodestone
```

Three.js is a peer dependency. Most package managers (npm v7+) install it automatically:

```bash
npm install three
```

## Quick Start

```ts
import { Structure, ThreeStructureRenderer, loadDefaultPackResources } from '@mattzh72/lodestone'
import { mat4 } from 'gl-matrix'

const { resources } = await loadDefaultPackResources()

const structure = new Structure([4, 3, 4])
structure.addBlock([0, 0, 3], 'minecraft:stone')
structure.addBlock([0, 1, 3], 'minecraft:cactus', { age: '1' })

const renderer = new ThreeStructureRenderer(canvas, structure, resources)
renderer.setViewport(0, 0, canvas.width, canvas.height)

const view = mat4.create()
mat4.translate(view, view, [0, 0, -5])
renderer.drawStructure(view)
```

For a complete example with item rendering and controls, see `demo/main.ts`.

## Usage

### Loading Litematic Files

Lodestone can load `.litematic` files (the schematic format used by Litematica mod):

```ts
import { LitematicLoader, ThreeStructureRenderer, loadDefaultPackResources } from '@mattzh72/lodestone'

// Load litematic file
const response = await fetch('path/to/build.litematic')
const buffer = await response.arrayBuffer()
const structure = LitematicLoader.load(new Uint8Array(buffer))

// Get metadata
const metadata = LitematicLoader.getMetadata(new Uint8Array(buffer))
console.log(metadata.name, metadata.author, metadata.totalBlocks)

// Render it
const { resources } = await loadDefaultPackResources()
const renderer = new ThreeStructureRenderer(canvas, structure, resources)
```

The loader handles gzip-compressed NBT parsing, variable-width bit-packed block state arrays, block palettes and properties, and multiple regions (loads first region by default).

### CDN Usage (UMD)

Load Three.js first, then Lodestone. The UMD bundle exposes `window.Lodestone`.

**Pinned version** (recommended for reproducible builds):

```html
<script src="https://unpkg.com/three@0.164.1/build/three.min.js"></script>
<script src="https://unpkg.com/@mattzh72/lodestone@0.4.0/dist/lodestone.umd.cjs"></script>
<script>
  // Load the built-in default pack from unpkg
  (async () => {
    const baseUrl = 'https://unpkg.com/@mattzh72/lodestone@0.4.0/assets/default-pack/'
    const { resources } = await Lodestone.loadDefaultPackResources({ baseUrl })
    // ...use resources with ThreeStructureRenderer
  })()
</script>
```

**Latest version** (convenient but may change):

```html
<script src="https://unpkg.com/three@0.164.1/build/three.min.js"></script>
<script src="https://unpkg.com/@mattzh72/lodestone@0.4.0/dist/lodestone.umd.cjs"></script>
<script>
  const { Structure, ThreeStructureRenderer } = window.Lodestone
</script>
```

### Custom Resource Packs

To use your own resource pack instead of the built-in default, provide a `Resources` object with:

- Block definitions (`blockstates/*.json`)
- Block models (`models/*.json`)
- Texture atlas (`ImageData`) and UV lookup
- Block flags (opaque, transparent, emissive)

See the `demo/` folder for a concrete implementation example.

## Development

Run the local demo:

```bash
npm install
npm run demo
```

## Contributing

Issues and pull requests are welcome! Visit the [issue tracker](https://github.com/mattzh72/lodestone/issues) to report bugs or suggest features.

## License

MIT. Lodestone includes upstream MIT-licensed code from [Misode](https://github.com/misode/deepslate).

## Acknowledgments

Special thanks to [deepslate](https://github.com/misode/deepslate)—Lodestone is an optimized, Three.js-native version of their work.