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https://github.com/pmndrs/gltfjsx

🎮 Turns GLTFs into JSX components
https://github.com/pmndrs/gltfjsx

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🎮 Turns GLTFs into JSX components

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README 

        
https://user-images.githubusercontent.com/2223602/126318148-99da7ed6-a578-48dd-bdd2-21056dbad003.mp4










[![Version](https://img.shields.io/npm/v/gltfjsx?style=flat&colorA=000000&colorB=000000)](https://www.npmjs.com/package/gltfjsx) [![Discord Shield](https://img.shields.io/discord/740090768164651008?style=flat&colorA=000000&colorB=000000&label=discord&logo=discord&logoColor=ffffff)](https://discord.gg/ZZjjNvJ)



A small command-line tool that turns GLTF assets into declarative and re-usable [react-three-fiber](https://github.com/pmndrs/react-three-fiber) JSX components.



### The GLTF workflow on the web is not ideal ...



- GLTF is thrown whole into the scene which prevents re-use, in threejs objects can only be mounted once

- Contents can only be found by traversal which is cumbersome and slow

- Changes to queried nodes are made by mutation, which alters the source data and prevents re-use

- Re-structuring content, making nodes conditional or adding/removing is cumbersome

- Model compression is complex and not easily achieved

- Models often have unnecessary nodes that cause extra work and matrix updates



### GLTFJSX fixes that



- 🧑‍💻 It creates a virtual graph of all objects and materials. Now you can easily alter contents and re-use.

- 🏎️ The graph gets pruned (empty groups, unnecessary transforms, ...) and will perform better.

- ⚡️ It will optionally compress your model with up to 70%-90% size reduction.



## Usage



```text

Usage

  $ npx gltfjsx [Model.glb] [options]



Options

  --output, -o        Output file name/path

  --types, -t         Add Typescript definitions

  --keepnames, -k     Keep original names

  --keepgroups, -K    Keep (empty) groups, disable pruning

  --bones, -b         Lay out bones declaratively (default: false)

  --meta, -m          Include metadata (as userData)

  --shadows, s        Let meshes cast and receive shadows

  --printwidth, w     Prettier printWidth (default: 120)

  --precision, -p     Number of fractional digits (default: 3)

  --draco, -d         Draco binary path

  --root, -r          Sets directory from which .gltf file is served

  --instance, -i      Instance re-occuring geometry

  --instanceall, -I   Instance every geometry (for cheaper re-use)

  --exportdefault, -E Use default export

  --transform, -T     Transform the asset for the web (draco, prune, resize)

    --resolution, -R  Resolution for texture resizing (default: 1024)

    --keepmeshes, -j  Do not join compatible meshes

    --keepmaterials, -M Do not palette join materials

    --format, -f      Texture format (default: "webp")

    --simplify, -S    Mesh simplification (default: false)

      --ratio         Simplifier ratio (default: 0)

      --error         Simplifier error threshold (default: 0.0001)

  --console, -c       Log JSX to console, won't produce a file

  --debug, -D         Debug output

```



### A typical use-case



First you run your model through gltfjsx. `npx` allows you to use npm packages without installing them.



```bash

npx gltfjsx model.gltf --transform

```



This will create a `Model.jsx` file that plots out all of the assets contents.



```jsx

/*

auto-generated by: https://github.com/pmdrs/gltfjsx

author: abcdef (https://sketchfab.com/abcdef)

license: CC-BY-4.0 (http://creativecommons.org/licenses/by/4.0/)

source: https://sketchfab.com/models/...

title: Model

*/



import { useGLTF, PerspectiveCamera } from '@react-three/drei'



export function Model(props) {

  const { nodes, materials } = useGLTF('/model-transformed.glb')

  return (

    

      

      

      

        

        

      

    

  )

}



useGLTF.preload('/model.gltf')

```



Add your model to your `/public` folder as you would normally do. With the `--transform` flag it has created a compressed copy of it (in the above case `model-transformed.glb`). Without the flag just copy the original model.



```text

/public

  model-transformed.glb

```



The component can now be dropped into your scene.



```jsx

import { Canvas } from '@react-three/fiber'

import { Model } from './Model'



function App() {

  return (

    

      

```



You can re-use it, it will re-use geometries and materials out of the box:



```jsx



```



Or make the model dynamic. Change its colors for example:



```jsx



```



Or exchange materials:



```jsx



  



```



Make contents conditional:



```jsx

{condition && }

```



Add events:



```jsx



```



## Features



#### ⚡️ Draco and meshopt compression ootb



You don't need to do anything if your models are draco compressed, since `useGLTF` defaults to a [draco CDN](https://www.gstatic.com/draco/v1/decoders/). By adding the `--draco` flag you can refer to [local binaries](https://github.com/mrdoob/three.js/tree/dev/examples/js/libs/draco/gltf) which must reside in your /public folder.



#### ⚡️ Preload your assets for faster response



The asset will be preloaded by default, this makes it quicker to load and reduces time-to-paint. Remove the preloader if you don't need it.



```jsx

useGLTF.preload('/model.gltf')

```



#### ⚡️ Auto-transform (compression, resize)



With the `--transform` flag it creates a binary-packed, draco-compressed, texture-resized (1024x1024), webp compressed, deduped, instanced and pruned *.glb ready to be consumed on a web site. It uses [glTF-Transform](https://github.com/donmccurdy/glTF-Transform). This can reduce the size of an asset by 70%-90%.



It will not alter the original but create a copy and append `[modelname]-transformed.glb`.



#### ⚡️ Type-safety



Add the `--types` flag and your GLTF will be typesafe.



```tsx

type GLTFResult = GLTF & {

  nodes: { robot: THREE.Mesh; rocket: THREE.Mesh }

  materials: { metal: THREE.MeshStandardMaterial; wood: THREE.MeshStandardMaterial }

}



export default function Model(props: JSX.IntrinsicElements['group']) {

  const { nodes, materials } = useGLTF('/model.gltf')

```



#### ⚡️ Easier access to animations



If your GLTF contains animations it will add [drei's](https://github.com/pmndrs/drei) `useAnimations` hook, which extracts all clips and prepares them as actions:



```jsx

const { nodes, materials, animations } = useGLTF('/model.gltf')

const { actions } = useAnimations(animations, group)

```



If you want to play an animation you can do so at any time:



```jsx

 actions.jump.play()} />

```



If you want to blend animations:



```jsx

const [name, setName] = useState("jump")

...

useEffect(() => {

  actions[name].reset().fadeIn(0.5).play()

  return () => actions[name].fadeOut(0.5)

}, [name])

```



#### ⚡️ Auto-instancing



Use the `--instance` flag and it will look for similar geometry and create instances of them. Look into [drei/Merged](https://github.com/pmndrs/drei#instances) to understand how it works. It does not matter if you instanced the model previously in Blender, it creates instances for each mesh that has a specific geometry and/or material.



`--instanceall` will create instances of all the geometry. This allows you to re-use the model with the smallest amount of drawcalls.



Your export will look like something like this:



```jsx

const context = createContext()

export function Instances({ children, ...props }) {

  const { nodes } = useGLTF('/model-transformed.glb')

  const instances = useMemo(() => ({ Screw1: nodes['Screw1'], Screw2: nodes['Screw2'] }), [nodes])

  return (

    

      {(instances) => }

    

  )

}



export function Model(props) {

  const instances = useContext(context)

  return (

    

      

      

    

  )

}

```



Note that similar to `--transform` it also has to transform the model. In order to use and re-use the model import both `Instances` and `Model`. Put all your models into the `Instances` component (you can nest).



The following will show the model three times, but you will only have 2 drawcalls tops.



```jsx

import { Instances, Model } from './Model'



  

  

  



```



## Using the parser stand-alone



```jsx

import { parse } from 'gltfjsx'

import { GLTFLoader, DRACOLoader } from 'three-stdlib'



const gltfLoader = new GLTFLoader()

const dracoloader = new DRACOLoader()

dracoloader.setDecoderPath('https://www.gstatic.com/draco/v1/decoders/')

gltfLoader.setDRACOLoader(dracoloader)



gltfLoader.load(url, (gltf) => {

  const jsx = parse(gltf, optionalConfig)

})

```



## Using the parser stand-alone for scenes (object3d's)



```jsx

const jsx = parse(scene, optionalConfig)

```



## Using GLTFStructureLoader stand-alone



The GLTFStructureLoader can come in handy while testing gltf assets. It allows you to extract the structure without the actual binaries and textures making it possible to run in a testing environment.



```jsx

import { GLTFStructureLoader } from 'gltfjsx'

import fs from 'fs/promises'



it('should have a scene with a blue mesh', async () => {

  const loader = new GLTFStructureLoader()

  const data = await fs.readFile('./model.glb')

  const { scene } = await new Promise((res) => loader.parse(data, '', res))

  expect(() => scene.children.length).toEqual(1)

  expect(() => scene.children[0].type).toEqual('mesh')

  expect(() => scene.children[0].material.color).toEqual('blue')

})

```



## Requirements



- Nodejs must be installed

- The GLTF file has to be present in your projects `/public` folder

- [three](https://github.com/mrdoob/three.js/) (>= 122.x)

- [@react-three/fiber](https://github.com/pmndrs/react-three-fiber) (>= 5.x)

- [@react-three/drei](https://github.com/pmndrs/drei) (>= 2.x)