glTF Pipeline

Content pipeline tools for optimizing glTF assets by Richard Lee and the Cesium team.

Supports common operations including: * Converting glTF to glb (and reverse) * Saving buffers/textures as embedded or separate files * Converting glTF 1.0 models to glTF 2.0 (using the KHRtechniqueswebgl and KHR_blend extensions) * Applying Draco mesh compression

gltf-pipeline

Getting Started

Install Node.js if you don't already have it, and then:

npm install -g gltf-pipeline

Using gltf-pipeline as a command-line tool:

Converting a glTF to glb

gltf-pipeline -i model.gltf -o model.glb

gltf-pipeline -i model.gltf -b

Converting a glb to glTF

gltf-pipeline -i model.glb -o model.gltf

gltf-pipeline -i model.glb -j

Converting a glTF to Draco glTF

gltf-pipeline -i model.gltf -o modelDraco.gltf -d

Saving separate textures

gltf-pipeline -i model.gltf -t

Using gltf-pipeline as a library:

Converting a glTF to glb:

const gltfPipeline = require('gltf-pipeline');
const fsExtra = require('fs-extra');
const gltfToGlb = gltfPipeline.gltfToGlb;
const gltf = fsExtra.readJsonSync('model.gltf');
gltfToGlb(gltf)
    .then(function(results) {
        fsExtra.writeFileSync('model.glb', results.glb);
    });

Converting a glb to glTF

const gltfPipeline = require('gltf-pipeline');
const fsExtra = require('fs-extra');
const glbToGltf = gltfPipeline.glbToGltf;
const glb = fsExtra.readFileSync('model.glb');
glbToGltf(glb)
    .then(function(results) {
        fsExtra.writeJsonSync('model.gltf', results.gltf);
    });

Converting a glTF to Draco glTF

const gltfPipeline = require('gltf-pipeline');
const fsExtra = require('fs-extra');
const processGltf = gltfPipeline.processGltf;
const gltf = fsExtra.readJsonSync('model.gltf');
const options = {
    dracoOptions: {
        compressionLevel: 10
    }
};
processGltf(gltf, options)
    .then(function(results) {
        fsExtra.writeJsonSync('model-draco.gltf', results.gltf);
    });

Saving separate textures

const gltfPipeline = require('gltf-pipeline');
const fsExtra = require('fs-extra');
const processGltf = gltfPipeline.processGltf;
const gltf = fsExtra.readJsonSync('model.gltf');
const options = {
    separateTextures: true
};
processGltf(gltf, options)
    .then(function(results) {
        fsExtra.writeJsonSync('model-separate.gltf', results.gltf);
        // Save separate resources
        const separateResources = results.separateResources;
        for (const relativePath in separateResources) {
            if (separateResources.hasOwnProperty(relativePath)) {
                const resource = separateResources[relativePath];
                fsExtra.writeFileSync(relativePath, resource);
            }
        }
    });

Command-Line Flags

|Flag|Description|Required| |----|-----------|--------| |

--help

-h

--input

-i

--output

-o

--binary

-b

false

--json

-j

false

--separate

-s

false

--separateTextures

-t

false

--stats

false

--keepUnusedElements

false

--draco.compressMeshes

-d

false

--draco.compressionLevel

7

--draco.quantizePositionBits

14

--draco.quantizeNormalBits

10

--draco.quantizeTexcoordBits

12

--draco.quantizeColorBits

8

--draco.quantizeGenericBits

12

--draco.unifiedQuantization

false

Build Instructions

Run the tests:

npm run test

npm run eslint

npm run eslint-watch

Building for CesiumJS integration

Some functionality of gltf-pipeline is used by CesiumJS as a third party library. The necessary files can be generated using:

npm run build-cesium

This will output a portion of the gltf-pipeline code into the

dist/cesium

Running Test Coverage

Coverage uses nyc. Run:

npm run coverage

coverage/lcov-report/index.html

The tests and coverage covers the Node.js module; it does not cover the command-line interface, which is tiny.

Generating Documentation

To generate the documentation:

npm run jsdoc

The documentation will be placed in the

doc

Contributions

Pull requests are appreciated! Please use the same Contributor License Agreement (CLA) and Coding Guide used for Cesium.