tinyobjloader

http://syoyo.github.io/tinyobjloader/

Tiny but poweful single file wavefront obj loader written in C++. No dependency except for C++ STL. It can parse 10M over polygons with moderate memory and time.

Good for embedding .obj loader to your (global illumination) renderer ;-)

What's new

• Sep 14, 2014 : Add support for multi-material per object/group. Thanks Mykhailo!
• Mar 17, 2014 : Fixed trim newline bugs. Thanks ardneran!
• Apr 29, 2014 : Add API to read .obj from std::istream. Good for reading compressed .obj or connecting to procedural primitive generator. Thanks burnse!
• Apr 21, 2014 : Define default material if no material definition exists in .obj. Thanks YarmUI!
• Apr 10, 2014 : Add support for parsing 'illum' and 'd'/'Tr' statements. Thanks mmp!
• Jan 27, 2014 : Added CMake project. Thanks bradc6!
• Nov 26, 2013 : Performance optimization by NeuralSandwich. 9% improvement in his project, thanks!
• Sep 12, 2013 : Added multiple .obj sticher example.

Example

tinyobjloader can successfully load 6M triangles Rungholt scene. http://graphics.cs.williams.edu/data/meshes.xml

Use case

TinyObjLoader is successfully used in ...

• bullet3 https://github.com/erwincoumans/bullet3
• pbrt-v2 https://https://github.com/mmp/pbrt-v2
• OpenGL game engine development http://swarminglogic.com/jotting/2013_10_gamedev01
• mallie https://lighttransport.github.io/mallie
• Your project here!

Features

• Group(parse multiple group name)
• Vertex
• Texcoord
• Normal
• Material
  • Unknown material attributes are treated as key-value.

Notes

Polygon is converted into triangle.

TODO

• Support quad polygon and some tags for OpenSubdiv http://graphics.pixar.com/opensubdiv/

License

Licensed under 2 clause BSD.

Usage

std::string inputfile = "cornell_box.obj";
std::vector<tinyobj::shape_t> shapes;
std::vector<tinyobj::material_t> materials;

std::string err = tinyobj::LoadObj(shapes, materials, inputfile.c_str());

if (!err.empty()) {
  std::cerr << err << std::endl;
  exit(1);
}

std::cout << "# of shapes    : " << shapes.size() << std::endl;
std::cout << "# of materials : " << materials.size() << std::endl;

for (size_t i = 0; i < shapes.size(); i++) {
  printf("shape[%ld].name = %s\n", i, shapes[i].name.c_str());
  printf("Size of shape[%ld].indices: %ld\n", i, shapes[i].mesh.indices.size());
  printf("Size of shape[%ld].material_ids: %ld\n", i, shapes[i].mesh.material_ids.size());
  assert((shapes[i].mesh.indices.size() % 3) == 0);
  for (size_t f = 0; f < shapes[i].mesh.indices.size() / 3; f++) {
    printf("  idx[%ld] = %d, %d, %d. mat_id = %d\n", f, shapes[i].mesh.indices[3*f+0], shapes[i].mesh.indices[3*f+1], shapes[i].mesh.indices[3*f+2], shapes[i].mesh.material_ids[f]);
  }

  printf("shape[%ld].vertices: %ld\n", i, shapes[i].mesh.positions.size());
  assert((shapes[i].mesh.positions.size() % 3) == 0);
  for (size_t v = 0; v < shapes[i].mesh.positions.size() / 3; v++) {
    printf("  v[%ld] = (%f, %f, %f)\n", v,
      shapes[i].mesh.positions[3*v+0],
      shapes[i].mesh.positions[3*v+1],
      shapes[i].mesh.positions[3*v+2]);
  }
}

for (size_t i = 0; i < materials.size(); i++) {
  printf("material[%ld].name = %s\n", i, materials[i].name.c_str());
  printf("  material.Ka = (%f, %f ,%f)\n", materials[i].ambient[0], materials[i].ambient[1], materials[i].ambient[2]);
  printf("  material.Kd = (%f, %f ,%f)\n", materials[i].diffuse[0], materials[i].diffuse[1], materials[i].diffuse[2]);
  printf("  material.Ks = (%f, %f ,%f)\n", materials[i].specular[0], materials[i].specular[1], materials[i].specular[2]);
  printf("  material.Tr = (%f, %f ,%f)\n", materials[i].transmittance[0], materials[i].transmittance[1], materials[i].transmittance[2]);
  printf("  material.Ke = (%f, %f ,%f)\n", materials[i].emission[0], materials[i].emission[1], materials[i].emission[2]);
  printf("  material.Ns = %f\n", materials[i].shininess);
  printf("  material.Ni = %f\n", materials[i].ior);
  printf("  material.dissolve = %f\n", materials[i].dissolve);
  printf("  material.illum = %d\n", materials[i].illum);
  printf("  material.map_Ka = %s\n", materials[i].ambient_texname.c_str());
  printf("  material.map_Kd = %s\n", materials[i].diffuse_texname.c_str());
  printf("  material.map_Ks = %s\n", materials[i].specular_texname.c_str());
  printf("  material.map_Ns = %s\n", materials[i].normal_texname.c_str());
  std::map<std::string, std::string>::const_iterator it(materials[i].unknown_parameter.begin());
  std::map<std::string, std::string>::const_iterator itEnd(materials[i].unknown_parameter.end());
  for (; it != itEnd; it++) {
    printf("  material.%s = %s\n", it->first.c_str(), it->second.c_str());
  }
  printf("\n");
}