pygltflib 1.6

Python library for reading, writing and managing 3D objects in the Khronos Group gltf and gltf2 formats. Python 3.6+

pygltflib

Python library for reading, writing and handling GLTF files. Python3.6+

Requirements

• Python 3.6+
• dataclasses
• dataclasses-json
• pytest (optional)

It requires python 3.6 and above because it uses dataclasses and all attributes are type hinted. And f-strings, plenty of f-strings.

About

This is an unofficial library that tracks the official file format for GLTF2.

The library was initially built to load and save simple meshes but support for the entire spec, including materials and animations is pretty good. Supports both json (.gltf) and binary (.glb) file formats, although .glb support is missing some features at the moment.

Check the table below for an idea of which sample models validate.

Questions? Contributions? Bug reports? Open an issue on the gitlab page for the project. We are very interested in hearing your use cases for pygltflib to help drive the roadmap.

Roadmap:

• Add helper functions for creating meshes
• Full support for binary GLTF (.glb) files
• Reject file overwrites unless overwrite flag set
• Give options on storing binary buffers (embedded vs external)

Contributors:

• Luke Miller
• Sebastian Höffner
• Arthur van Hoff

Changelog:

• 1.6
  • provide better support for binary (.glb) files (bug fixes)
  • promote load_json, load_binary, save_json and save_binary from internal methods
• 1.5
  • align embedded data correctly
  • add def glb2gltf and def gltf2glb util functions to pygltflib.utils for easy file conversion
• 1.4
  • add basic support for saving to binary GLTF (.glb) files
  • move undocumented non-core methods to pygltfib.utils
• 1.3
  • add basic support for reading binary GLTF (.glb) files
• 1.2
  • provide better json support
  • remove numpy requirement
  • suppress infer warning
  • add basic default methods
• 1.0
  • initial release

Install

PIP

Method 1

pip install pygltflib

Method 2

python -m pip install pygltflib

Method 3

py -3 -m pip install pygltflib

Source

git clone https://gitlab.com/dodgyville/pygltflib

Usage

Note: These examples use the official sample models provided by Khronos at:

https://github.com/KhronosGroup/glTF-Sample-Models

Creating

>>> from pygltflib import GLTF2, Scene
>>> gltf = GLTF2()
>>> gltf.scene # no scene set by default
>>> len(gltf.scenes)
0

>>> scene = Scene()
>>> gltf.scenes.append(scene)
>>> len(gltf.scenes)
1

Loading and saving

pygltflib can load json-based .GLTF files and binary .GLB files, based on the file extension.

GLTF files

>>> from pygltflib import GLTF2
>>> filename = "glTF-Sample-Models/2.0/AnimatedCube/glTF/AnimatedCube.gltf"
>>> gltf = GLTF2().load(filename)
>>> gltf.scene
0

>>> gltf.scenes
[Scene(name='', nodes=[0])]

>>> gltf.nodes[0]
Node(mesh=0, skin=None, rotation=[0.0, -1.0, 0.0, 0.0], translation=[], scale=[], children=[], matrix=[], camera=None, name='AnimatedCube')
>>> gltf.nodes[0].name
'AnimatedCube'

>>> gltf.meshes[0].primitives[0].attributes
Attributes(NORMAL=4, POSITION=None, TANGENT=5, TEXCOORD_0=6)

>>> filename2 = "test.gltf"
>>> gltf.save(filename2)

GLB files

>>> from pygltflib import GLTF2
>>> glb_filename = "glTF-Sample-Models/2.0/Box/glTF-Binary/Box.glb"
>>> glb = GLTF2().load(glb_filename)
>>> glb.scene
0

>>> glb.scenes
[Scene(name='', nodes=[0])]

>>> glb.nodes[0]
Node(mesh=None, skin=None, rotation=[], translation=[], scale=[], children=[1], matrix=[1.0, 0.0, 0.0, 0.0, 0.0, 0.0, -1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0], camera=None, name=None)

>>> glb.meshes[0].primitives[0].attributes
Attributes(POSITION=2, NORMAL=1, TANGENT=None, TEXCOORD_0=None, TEXCOORD_1=None, COLOR_0=None, JOINTS_0=None, WEIGHTS_0=None)

>>> glb.save("test.glb")

Converting files

First method

>>> from pygltflib import GLTF2

>>> # convert glb to gltf
>>> glb = GLTF2().load("glTF-Sample-Models/2.0/Box/glTF-Binary/Box.glb")
>>> glb.save("test.gltf")

>>> # convert gltf to glb
>>> gltf = GLTF2().load("glTF-Sample-Models/2.0/Box/glTF/Box.gltf")
>>> gltf.save("test.glb")

Second method using utils

>>> from pygltflib.utils import glb2gltf, gltf2glb
>>> # convert glb to gltf
>>> glb2gltf("glTF-Sample-Models/2.0/Box/glTF-Binary/Box.glb")

>>> # convert gltf to glb
>>> gltf2glb("glTF-Sample-Models/2.0/Box/glTF/Box.gltf", "test.glb", override=True)

Running the tests

Status of gltf-validator

Using sample models loaded and then saved using this library, here are validator reports (blank is untested).

Validator Status

Model	gltf to gltf	gltf to glb
2CylinderEngine	passes	fail
AlphaBlendModeTest	passes	fail
AnimatedCube	passes	passes
AnimatedMorphCube	passes	passes
AnimatedMorphSphere	passes	passes
AnimatedTriangle	passes	fail
Avocado	passes	passes
BarramundiFish	passes
BoomBox	passes
BoomBoxWithAxes	passes
Box	passes	fail
BoxAnimated	passes
BoxInterleaved	passes
BoxTextured	passes
BoxTexturedNonPowerOfTwo	passes
BoxVertexColors	passes
BrainStem	passes
Buggy	passes
Cameras	passes	passes
CesiumMan	passes
CesiumMilkTruck	passes
Corset	passes
Cube	passes	passes
DamagedHelmet	passes	passes
Duck	passes	fail
FlightHelmet	passes
GearboxAssy	passes
Lantern	passes
MetalRoughSpheres	passes
Monster	passes
MultiUVTest	passes
NormalTangentMirrorTest	passes
NormalTangentTest	passes
OrientationTest	passes
ReciprocatingSaw	passes
RiggedFigure	passes	fail
RiggedSimple	passes	fail
SciFiHelmet	passes	passes
SimpleMeshes	passes
SimpleMorph	passes
SimpleSparseAccessor	passes
SpecGlossVsMetalRough	passes
Sponza	passes
Suzanne	passes
TextureCoordinateTest	passes
TextureSettingsTest	passes	fail
TextureTransformTest	passes
Triangle	passes
TriangleWithoutIndices	passes
TwoSidedPlane	passes
VC	passes
VertexColorTest	passes
WaterBottle	passes	passes

unittests

pytest tests.py