Header only C++ tiny glTF 2.0 library
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README.md

Header only C++ tiny glTF library(loader/saver).

TinyGLTF is a header only C++11 glTF 2.0 https://github.com/KhronosGroup/glTF library.

TinyGLTF uses Niels Lohmann's json library(https://github.com/nlohmann/json), so now it requires C++11 compiler. If you are looking for old, C++03 version, please use devel-picojson branch.

Status

v2.0.0 release(22 Aug, 2018)!

Builds

Build Status

Build status

Features

  • Written in portable C++. C++-11 with STL dependency only.
    • macOS + clang(LLVM)
    • iOS + clang
    • Linux + gcc/clang
    • Windows + MinGW
    • Windows + Visual Studio 2015 Update 3 or later.
      • Visual Studio 2013 is not supported since they have limited C++11 support and failed to compile json.hpp.
    • Android NDK
    • Android + CrystaX(NDK drop-in replacement) GCC
    • Web using Emscripten(LLVM)
  • Moderate parsing time and memory consumption.
  • glTF specification v2.0.0
    • ASCII glTF
    • Binary glTF(GLB)
    • PBR material description
  • Buffers
    • Parse BASE64 encoded embedded buffer data(DataURI).
    • Load .bin file.
  • Image(Using stb_image)
    • Parse BASE64 encoded embedded image data(DataURI).
    • Load external image file.
    • PNG(8bit only)
    • JPEG(8bit only)
    • BMP
    • GIF
    • Custom Image decoder callback(e.g. for decoding OpenEXR image)

Examples

  • glview : Simple glTF geometry viewer.
  • validator : Simple glTF validator with JSON schema.

Projects using TinyGLTF

TODOs

  • Write C++ code generator which emits C++ code from JSON schema for robust parsing.
  • Mesh Compression/decompression(Open3DGC, etc)
    • Load Draco compressed mesh
  • Support extensions and extras property
  • HDR image?
    • OpenEXR extension through TinyEXR.
  • Write example and tests for animation and skin

Licenses

TinyGLTF is licensed under MIT license.

TinyGLTF uses the following third party libraries.

  • json.hpp : Copyright (c) 2013-2017 Niels Lohmann. MIT license.
  • base64 : Copyright (C) 2004-2008 René Nyffenegger
  • stb_image.h : v2.08 - public domain image loader - Github link
  • stb_image_write.h : v1.09 - public domain image writer - Github link

Build and example

Copy stb_image.h, stb_image_write.h, json.hpp and tiny_gltf.h to your project.

Loading glTF 2.0 model

// Define these only in *one* .cc file.
#define TINYGLTF_IMPLEMENTATION
#define STB_IMAGE_IMPLEMENTATION
#define STB_IMAGE_WRITE_IMPLEMENTATION
// #define TINYGLTF_NOEXCEPTION // optional. disable exception handling.
#include "tiny_gltf.h"

using namespace tinygltf;

Model model; 
TinyGLTF loader;
std::string err;
std::string warn;
  
bool ret = loader.LoadASCIIFromFile(&model, &err, &warn, argv[1]);
//bool ret = loader.LoadBinaryFromFile(&model, &err, &warn, argv[1]); // for binary glTF(.glb) 

if (!warn.empty()) {
  printf("Warn: %s\n", warn.c_str());
}

if (!err.empty()) {
  printf("Err: %s\n", err.c_str());
}

if (!ret) {
  printf("Failed to parse glTF\n");
  return -1;
}

Compile options

  • TINYGLTF_NOEXCEPTION : Disable C++ exception in JSON parsing. You can use -fno-exceptions or by defining the symbol JSON_NOEXCEPTION and TINYGLTF_NOEXCEPTION to fully remove C++ exception codes when compiling TinyGLTF.
  • TINYGLTF_NO_STB_IMAGE : Do not load images with stb_image. Instead use TinyGLTF::SetImageLoader(LoadimageDataFunction LoadImageData, void *user_data) to set a callback for loading images.
  • TINYGLTF_NO_STB_IMAGE_WRITE : Do not write images with stb_image_write. Instead use TinyGLTF::SetImageWriter(WriteimageDataFunction WriteImageData, void *user_data) to set a callback for writing images.

Saving gltTF 2.0 model

  • Buffers.
    • To file
    • Embedded
    • Draco compressed?
  • Images
    • To file
    • Embedded
  • Binary(.glb)

Running tests.

glTF parsing test

Setup

Python 2.6 or 2.7 required. Git clone https://github.com/KhronosGroup/glTF-Sample-Models to your local dir.

Run parsing test

After building loader_example, edit test_runner.py, then,

$ python test_runner.py

Unit tests

$ cd tests
$ make
$ ./tester
$ ./tester_noexcept

Third party licenses

  • json.hpp : Licensed under the MIT License http://opensource.org/licenses/MIT. Copyright (c) 2013-2017 Niels Lohmann http://nlohmann.me.
  • stb_image : Public domain.
  • catch : Copyright (c) 2012 Two Blue Cubes Ltd. All rights reserved. Distributed under the Boost Software License, Version 1.0.