markaren/threepp

C++20 port of three.js (r129)

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]
• 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.

Windows

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

Unix

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

However, some of the examples (and headers) require additional dependencies. To make use of all features and to enable/build all examples, the use of vcpkg is encouraged.

vcpkg (using manifest mode)

Call CMake with -DCMAKE_TOOLCHAIN_FILE=[path to vcpkg]/scripts/buildsystems/vcpkg.cmake

Add optional features by listing them with -DVCPKG_MANIFEST_FEATURES=feature1;feature2

See vcpkg.json for available features.

Note, however, that under MinGW you'll need to specify the vcpkg triplet:

-DVCPKG_TARGET_TRIPLET=x64-mingw-[static|dynamic]  # choose either `static` or `dynamic`.
-DVCPKG_HOST_TRIPLET=x64-mingw-[static|dynamic]    # <-- needed only if MSVC cannot be found. 

Building examples with Emscripten

Pass to CMake:

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

When using vcpkg, however, do:

-DVCPKG_CHAINLOAD_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 in order 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

#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:

include(FetchContent)
set(THREEPP_BUILD_TESTS OFF)
set(THREEPP_BUILD_EXAMPLES OFF)
FetchContent_Declare(
        threepp
        GIT_REPOSITORY https://github.com/markaren/threepp.git
        GIT_TAG tag_or_commit_hash
)
FetchContent_MakeAvailable(threepp)
#...
target_link_libraries(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