mola_mapper

Central SLAM map for the MOLA framework, compatible with ROS 2.

mola_mapper holds one global, optimized representation of the world, fusing multiple odometry sources (wheels, LiDAR-odometry, visual-odometry), IMU and GNSS into a single keyframe-based map (a mrpt::maps::CSimpleMap backed by a GTSAM iSAM2 factor graph), with anytime loop closure, geo-referencing, lifelong keyframe management, and relocalization.

Contents

This repository provides a C++ library mola_mapper implementing the central 3D SLAM back-end. It exposes the following mola_kernel interfaces:

Interface	Role
mola::NavStateFilter	Single source of truth for short-term pose prediction queried by LIO/VIO front-ends
mola::LocalizationSourceBase	Fused vehicle localization (published at high rate)
mola::MapSourceBase	Map and geo-referencing
mola::SharedKeyframeMap	Receives keyframe-insert requests from LIO/VIO front-ends
mola::DiagnosticsProvider	Structured diagnostics

ROS 2 example launch files are provided in ros2-launchs and mola-cli-launchs.

Build and install

Refer to: https://docs.mola-slam.org/latest/#installing

Documentation and tutorials

See: https://docs.mola-slam.org/latest/mola_mapper.html

ROS build farm status

Distro	Develop branch	Releases	Stable release
ROS2 Humble (u22.04)		amd64 arm64
ROS 2 Jazzy @ u24.04		amd64 arm64
ROS 2 Kilted @ u24.04		amd64 arm64
ROS 2 Lyrical (u26.04)		amd64 arm64
ROS 2 Rolling (u26.04)		amd64 arm64

Repository layout

module/include/mola_mapper/   Public headers (Mapper, Parameters, WorldModelState)
module/src/                      Implementation (split by concern)
apps/                            mola-mapper-3d-cli (offline front-end)
params/                          Default YAML configuration
mola-cli-launchs/                mola-cli launch files
ros2-launchs/                    ROS 2 launch files
docs/                            Sphinx/RST documentation pages
test/                            Unit tests

Citation

The latest publication on MOLA is (ArXiV).

@article{blanco2025mola_lo,
    author = {Blanco-Claraco, Jose Luis},
    title ={{A flexible framework for accurate LiDAR odometry, map manipulation, and localization}},
    journal = {The International Journal of Robotics Research},
    volume = {44},
    number = {9},
    pages = {1553--1599},
    year = {2025},
    doi = {10.1177/02783649251316881},
    URL = { https://doi.org/10.1177/02783649251316881},
    eprint = {2407.20465},
}

License

Copyright (C) 2018-2026 Jose Luis Blanco jlblanco@ual.es, University of Almeria

This package is released under the GNU GPL v3 license as open source, with the main intention of being useful for research and evaluation purposes. Commercial licenses available upon request.

Contributions require acceptance of the Contributor License Agreement (CLA).