Selmar / tinygltf

Header only C++ tiny glTF 2.0 library

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

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

Status

Work in process(devel branch). Very near to release, but need more tests and examples.

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.

Builds

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 or later.
    • Visual Studio 2013 is not supported since they have limited C++11 support and failed to compile json.hpp.
  • 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 fata(DataURI).
  • Load .bin file.
• Image(Using stb_image)
  • Parse BASE64 encoded embedded image fata(DataURI).
  • Load external image file.
  • PNG(8bit only)
  • JPEG(8bit only)
  • BMP
  • GIF

Examples

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

TODOs

• Write C++ code generator from json schema for robust parsing.
• Serialization
• Compression/decompression(Open3DGC, etc)
• Support extensions and extras property
• HDR image?
• Write 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 - http://nothings.org/stb_image.h

Build and example

Copy stb_image.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 TINYGLTF_NOEXCEPTION // optional. disable exception handling.
#include "tiny_gltf.h"

using namespace tinygltf;

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

Saving gltTF 2.0 model

T.B.W.

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.