threepp (Work in progress)

Cross-platform C++20 port of the popular Javascript 3D library three.js r129.

Current state of the project

Most of the core library has been ported, including advanced rendering capabilities, however much remains to be done..

What works?

• Line, Points, Mesh, InstancedMesh
• Geometries [Box, Sphere, Plane, Cylindrical, Capsule, Tube, ++]
  
• Lights [Ambient, Directional, Point, Spot, Hemi]
• Raycasting [Mesh, Line, Points]
• 2D/3D Textures, 3D text, Sprites, RenderTarget, CubeMaps
• Transparency, Shadows
• Morphtargets, Bones
• Controls [Orbit, Fly, Drag]
• Water and Sky shaders
• Built-in text rendering and font loading [typeface.json, TTF]
• Loaders [Binary STL, OBJ/MTL, SVG, URDF]
• Animations (limited to transforms)
• Basic Audio support using miniaudio
• Generic model loader based on Assimp
• Easy integration with Dear ImGui

Builds on Windows, Linux, MacOS, MinGW and with Emscripten.

But, but why?

Because fun.

How to build

threepp comes bundled with all required core dependencies.

Use CMake for project configuration and building.

Do note that you may also use a system installation of GLFW3 if you want or have issues with the bundled setup by passing -DTHREEPP_USE_EXTERNAL_GLFW=ON to CMake.

Windows

shell cmake . -A x64 -B build -DCMAKE_BUILD_TYPE="Release" cmake --build build --config "Release"

Unix

shell cmake . -B build -DCMAKE_BUILD_TYPE="Release" cmake --build build

Building examples with Emscripten

Pass to CMake: shell -DCMAKE_TOOLCHAIN_FILE="[path to emscripten]\emsdk\upstream\emscripten\cmake\Modules\Platform\Emscripten.cmake"

This will generate .html versions of a subset of the examples to be loaded in a browser.

Optional downstream dependencies

When consuming threepp in your own application, some headers will require additional dependencies to compile.

| Header | Dependency | Description | |--------------|----------------|-----------------------------------------------| | AssimpLoader | assimp | Import a wide variety of different 3D formats | | ImguiContext | imgui | ImGUI utility |

Implementation notes

In general, you'll find that math classes are value types, while threepp expect smart pointers for other types. For convenience, geometries, materials etc. has a static ::create function that returns a std::shared_ptr. Thus, you don't necessarily need to handle memory explicitly using threepp. Furthermore, materials, geometries and textures are automatically disposed when they go out of scope. Yay!

Example

```cpp

include "threepp/threepp.hpp"

using namespace threepp;

auto createBox(const Vector3& pos, const Color& color) { auto geometry = BoxGeometry::create(); auto material = MeshPhongMaterial::create(); material->color = color;

auto box = Mesh::create(geometry, material);
box->position.copy(pos);

return box;

}

auto createPlane() { auto planeGeometry = PlaneGeometry::create(5, 5); auto planeMaterial = MeshLambertMaterial::create(); planeMaterial->color = Color::gray; planeMaterial->side = Side::Double;

auto plane = Mesh::create(planeGeometry, planeMaterial);
plane->position.y = -1;
plane->rotateX(math::degToRad(90));

return plane;

}

int main() {

Canvas canvas("Demo");
GLRenderer renderer{canvas.size()};

auto scene = Scene::create();
auto camera = PerspectiveCamera::create(75, canvas.aspect(), 0.1f, 100);
camera->position.z = 5;

OrbitControls controls{*camera, canvas};

auto light = HemisphereLight::create();
scene->add(light);

auto plane = createPlane();
scene->add(plane);

auto group = Group::create();
group->add(createBox({-1, 0, 0}, Color::green));
group->add(createBox({1, 0, 0}, Color::red));
scene->add(group);

canvas.onWindowResize([&](WindowSize size) {
    camera->aspect = size.aspect();
    camera->updateProjectionMatrix();
    renderer.setSize(size);
});

Clock clock;
canvas.animate([&]() {

    float dt = clock.getDelta();
    group->rotation.y += 1.f * dt;

    renderer.render(*scene, *camera);
});

}

```

Consuming threepp

Threepp is available as a CMake package and can be consumed in a number of ways.

CMake FetchContent (recommended)

threepp is compatible with CMake's FetchContent:

```cmake include(FetchContent) set(THREEPPBUILDTESTS OFF) set(THREEPPBUILDEXAMPLES OFF) FetchContentDeclare( threepp GITREPOSITORY https://github.com/markaren/threepp.git GITTAG tagorcommithash ) FetchContent_MakeAvailable(threepp)

...

targetlinklibraries(main PUBLIC threepp::threepp) ```

This is the preferred approach, as it enables users to update the targeted threepp version at will.

An example is provided here. See also this demo, which additionally uses WxWidgets as the Window system.

Screenshots