# erincatto/box3d

Box3D is a 3D physics engine for games

Repository: https://github.com/erincatto/box3d
Canonical: https://ross.abutalabs.com/products/box3d
Language: C
License: MIT
License Family: permissive
Last push: 2026-08-19T18:19:04+00:00

## Health v2 (maintenance only)
Score: 66/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 58, longevity 8
- inputs: {"age_days": 115, "days_push": 14, "days_rel": 64, "gap_med": null, "n_releases_24m": 1}
- flags: young
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 6174, forks 307 (observed 2026-08-28T04:09:36.908320+00:00)

## What it is
Box3D is a 3D rigid body physics engine for games, written in portable C17 with a data-oriented design. It provides collision detection, joint systems, continuous physics, and cross-platform determinism with multithreading and SIMD support.

## Use cases
- simulate rigid body physics in a 3D game
- collision detection with convex hulls and triangle meshes
- build a character controller with a physics mover
- deterministic physics for replay and networking
- ray casting and shape casting queries in a 3D world
- physics simulation with joints, motors, and springs

## When to choose
- you need a fast, deterministic 3D physics engine in C or C++
- you want continuous collision detection for fast-moving bodies
- you need cross-platform builds including web via Emscripten
- you are simulating large numbers of bodies with multithreading and SIMD

## When to avoid
- you need 2D physics (use Box2D instead)
- you need a full game engine with rendering and asset pipelines
- you require a high-level scripting or visual physics editor
- you need soft-body or fluid simulation

## Facets
- artifact type: library
- maturity: active
- function: simulation, graphics, game-engine, math, concurrency
- domain: simulation, graphics, cross-platform
- platform: cpp, c, windows, wasm, cross-platform
- tags: physics-engine, rigid-body-dynamics, collision-detection, 3d, game-development, deterministic-simulation, simd, macos, linux

## Member repositories
- erincatto/box3d (main) score 66

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:36.908320+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:47:26.634353+00:00, confidence not recorded.
  - readme: https://github.com/erincatto/box3d (fetched 2026-08-28T04:09:36.908320+00:00, sha d7d5de61cfa8)
- Data as of 2026-08-30T08:39:29.467469+00:00.