threepp
A cross-platform C++20 3D library with the high-level API of three.js,
and two backends behind one scene graph: portable OpenGL, and a deferred Vulkan renderer with
ray-traced shadows, reflections, AO and GI.
On top of that: a scene editor, PhysX robot simulation, simulated sensors with ground-truth labels
for synthetic data, hardware-in-the-loop flight with ArduPilot, and Python bindings on PyPI.
An Otter X sea drone under way in a digital twin of a real waterfront in Ålesund, Norway, modelled
from Kartverket lidar and sea charts and rendered by the Vulkan backend: the water reflects the
moored boats and the buildings ashore (the scene is not in the repository)
New here? Getting started walks through the concepts the library is
built from: the scene graph, ownership and lifetimes, geometry and materials, lights, the frame
loop, loaders and the two backends. The examples folder is the de-facto reference.
Features
three.js parity. The API follows three.js r129,
with selected features from r186 on the OpenGL path (shadow filtering, environment and background
controls, material fixes, the newer post-processing passes).
- Mesh, InstancedMesh, Line, Points, Sprites, 2D/3D text (typeface.json and TTF)
- The usual geometries, lights (including RectArea), cameras, raycasting, animation, morph targets and bones
- Physical materials with transmission, alpha hash and alpha-to-coverage; PMREM environment maps and
RoomEnvironment
- Shadows, Water and Sky shaders, and Orbit, Trackball, Fly, Drag and Transform controls
EffectComposer with bloom, depth of field, GTAO, outline, FXAA and output passes- Loaders: glTF/GLB (with meshopt), OBJ/MTL, STL, COLLADA, SVG, URDF/xacro (no ROS needed), PNG/JPEG, DDS, WebP, HDR and EXR; opt-in USD and Assimp
- Scene serialization as three.js Object JSON or a single-file
.tpz archive; three.js editor documents load as-is
Rendering beyond three.js
- A deferred Vulkan renderer: raster G-buffer, ray-traced shadows (or cascaded shadow maps), reflections,
AO and probe GI, volumetric fog, denoising and TAA, DLSS and FSR 3.1 upscaling, automatic mesh LOD and
GPU occlusion culling
Ocean (Vulkan): three-cascade FFT water with foam, wind, JONSWAP fetch and an underwater viewParticleField (Vulkan): GPU particles for fire, smoke, snow, rain and physics-coupled grains,
drawn as meshes or billboards, or marched as participating media- Gaussian splatting:
SplatCloud renders .ply and SOG scans on both backends, and a scan can be
baked into a triangle surface for physics and sensors (doc/vulkan_splats.md)
Simulation and perception
- Ground-truth labels from the G-buffer (Vulkan): metric depth, stable instance ids, semantic
classes, normals and motion;
addView renders a whole camera rig from one scene build
- Simulated sensors: lidar (VLP-16, HDL-32E, OS1-64, OS0-128 patterns), imaging sonar (Vulkan),
depth, colour and event cameras, IMU, joint encoders, contact and force/torque. Seeded and
sim-clock stamped: drive
setSimTime from the same clock and a frame replays bit for bit
- A physical camera: exposure from aperture, shutter and ISO, OpenCV intrinsics, lens distortion
applied to both image and labels, and sensor noise
- PhysX: rigid bodies, articulations built from URDF/xacro with PD drives, tendons and cables, soft
bodies, GPU particles, vehicles, character controllers and V-HACD convex decomposition, plus a
damped-least-squares IK solver
- Soft and granular ground from Python on NVIDIA Warp: Bekker-Wong mud and snow, and MLS-MPM grains
that carry a wheel, checked against terramechanics data
- Hardware-in-the-loop: an unmodified ArduPilot flies a threepp airframe in lock-step
(doc/ardupilot_sitl.md)
- Zero-copy CUDA interop: an external producer such as NVIDIA Warp writes vertex buffers in place,
and rendered frames come back as CUDA tensors
Content and tooling
- Procedural terrain, trees, grass, roads, conveyors, bird flocks and a log cabin; real-world
terrain built from Norwegian open data (
terrain::GeoScene)
- Audio via miniaudio, with ray-traced occlusion and reverb (
AcousticScene)
- Dear ImGui integration
- Builds on Windows, Linux, macOS, MinGW and with Emscripten
Applications
threepp_editor: viewport, hierarchy, inspector, undo/redo and a PhysX-backed Play mode, with
Python behaviour scripts. Scenes save as plain three.js JSON with the editor's data in userData,
so they also run in an ordinary threepp program. Prebuilt for Windows: pip install threepp-editor.
See doc/editor.md.threepp_player: the same play runtime, headless, for CI and batch episodes. See doc/player.md.
Both build alongside the library in a top-level build (THREEPP_BUILD_EDITOR).
Project status
threepp is built for research, prototyping and teaching, not as a production engine. APIs change,
so pin a tag or commit if you need reproducibility.
This is the beginning of the README. Read the rest at the original. Read the full README ↗
