# strasdat/Sophus

C++ implementation of Lie Groups using Eigen.

Repository: https://github.com/strasdat/Sophus
Canonical: https://ross.abutalabs.com/products/sophus
Language: C++
License: NOASSERTION
License Family: other
Topics: c-plus-plus, math, robotics, computer-vision, geometry, graphics, 3d, 2d, python
Last push: 2024-07-06T18:06:55+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 5384, "days_push": 788, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2447, forks 671 (observed 2026-08-28T04:06:52.778303+00:00)

## What it is
Sophus is a C++ template library implementing 2D and 3D Lie groups (SO(2), SO(3), SE(2), SE(3)) built on top of Eigen, commonly used for geometric computations in computer vision and robotics. It also offers Python bindings via pybind11 and is now in maintenance mode with successor projects (sophus2, sophus-rs) under development.

## Use cases
- represent 3D rotations and rigid body transformations in SLAM pipelines
- compute SE(3) poses for camera extrinsics in computer vision
- perform Lie group algebra for robot state estimation
- interpolate and differentiate rotations for trajectory optimization
- use SO(3)/SE(3) types in visual odometry or bundle adjustment code
- prototype geometric algorithms in Python via pybind11 bindings

## When to choose
- you need well-tested C++ Lie group implementations integrated with Eigen
- you work on robotics, SLAM, or computer vision problems involving rotations and rigid transforms
- you want a header-only library with mature, widely adopted SO(2)/SO(3)/SE(2)/SE(3) support

## When to avoid
- you need new features or active development - the project is in maintenance mode
- you want camera models, splines, or nonlinear least squares - look at sophus2 or sophus-rs instead
- you need guaranteed Windows CI support or a permissive license (license is non-standard)

## Facets
- artifact type: library
- maturity: maintenance
- function: math, graphics, simulation
- domain: computer-vision, robotics, graphics, mathematics
- platform: cpp, windows, python
- tags: lie-groups, eigen, geometry, so3, se3, rotations, rigid-body-transformations, slam, header-only, algorithms, linux, macos

## Member repositories
- strasdat/Sophus (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:52.778303+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 2026-08-30T02:30:31.144711+00:00, confidence not recorded.
  - readme: https://github.com/strasdat/Sophus (fetched 2026-08-28T04:06:52.778303+00:00, sha 71e70fd482c2)
- Data as of 2026-08-30T08:39:29.467469+00:00.