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Migrating from Earlier API Versions

This page aims to briefly highlight changes in the API since previous versions that users should be aware of when migrating. For more detail please refer to example code distributed with the SDK or annotated in the C++ API examples section.

Slamcore SDK v23.01

Session file format

Slamcore SDK v23.01 brings several breaking changes, one of them being the session file format. Session files (.session) generated using older software versions (v21.06) will no longer be usable with v23.01 and above. You may use the new software to generate a new session file if you have retained the original dataset.

Please contact, providing your Slamcore account email address, if you require access to the v21.06 SDK packages and its supporting documentation to use in conjunction with your old session files.

JSON configuration file migration

The configuration file format for running SLAM on customized parameters has changed in this software version. This means that your old configuration files may fail to be parsed, or be parsed incorrectly when used with Slamcore SDK v23.01 and above. This affects any of the following:

To update your existing JSON configuration files, please install the “Slamcore Tools” package from the Slamcore Portal, run the slamcore_migrate_config tool and save the text output in a new .json file, for example:

$ slamcore_migrate_config vik_odometry_config.json >> new_vik_odometry_config.json

Tracking Information

We have redefined our tracking status information to better differentiate between the instantaneous status of the pose estimation and the events triggered only at certain frames to update SLAM.

The Relocalised and Loop Closure states are no longer reported under the “Tracking Status” information, and instead under a new “SLAM Event” metadata alongside a new IMU Initialization event. For more information please refer to Tracking Information.

Slamcore SDK v21.06.85


The API has been reorganised to provide more granular header files for development. Please be aware that some interfaces are no longer included by slamcore/slamcore.hpp and therefore must be included in the implementation file explicitly.

Subsystems and I/O

Accessing trajectories

Previously the slamcore::TrajectorySubsystemInterface subsystem offered access to both the unoptimised and optimised trajectories where available.

This functionality has been split into two classes as follows:

  • The slamcore::OptimisedTrajectorySubsystemInterface subsystem continues to offer access to the optimised trajectory from the SLAM instance.

  • The unoptimised trajectory must be accumulated by the client. To do so correctly the SDK provides the slamcore::TrajectoryHelper class.

Please see the write_trajectory.cpp example distributed with the SDK for detailed usage.

Wheel odometry integration

Integration of wheel odometry has been comprehensively re-implemented via a new slamcore::SensorSourceInterface. The slamcore::MobileRobotSubsystemInterface class has been removed.

Please see the wheel_odometry.cpp example distributed with the SDK for details regarding how to integrate wheel odometry.

Types and Objects

LogMessageInterface timestamps

slamcore::LogMessageInterface::getTimestamp() method has been modified to return a slamcore::host_timestamp.

Code that previously read:

void sample(const slamcore::LogMessageInterface& message)
  const time_t time = std::chrono::system_clock::to_time_t(message.getTimestamp());

Should be updated to:

void sample(const slamcore::LogMessageInterface& message)
  const time_t time = slamcore::host_clock::to_time_t(message.getTimestamp());

Renamed slamcore::CameraSensorsInfoInterface

The slamcore::CameraSensorsInfoInterface class has been replaced with slamcore::SensorsInfoInterface.

Re-implemented slamcore::MultiFrameInterface

The slamcore::MultiFrameInterface previously used slamcore::ImageInterface as its value_type. It has been modified to use the more general slamcore::FrameInterface.

To access a slamcore::MultiFrameInterface’s image for a given sensor, code that previously read:

void sample(const slamcore::MultiFrameInterface& multiFrame, const uint8_t sensorIndex)
  const slamcore::ImageInterface& image = multiFrame->get(sensorIndex);

Should be updated to:

void sample(const slamcore::MultiFrameInterface& multiFrame, const uint8_t sensorIndex)
  const slamcore::ImageInterface& image = multiFrame->get(sensorIndex).image();

Concrete Matrix class

Previously matrix and vector types were represented by the slamcore::Matrix and slamcore::Vector which adapted the std::vector to the slamcore::MatrixInterface and slamcore::VectorInterface respectively.

The implementation of slamcore::Matrix has been changed to a concrete template class which requires

  • the element type; and,

  • dimensions or slamcore::Dynamic

as template parameters. The corresponding interfaces have been removed, therefore all APIs now return the concrete type.

Any use of slamcore::Vector or slamcore::Matrix should be amended to include the required template parameters.

Pointers or references to returned interfaces should be changed to auto or the precise concrete type.

Removed slamcore::ObjectInterface

slamcore objects previously implemented the common slamcore::ObjectInterface to provide the object’s type(). This interface has been removed.

All calls to type() should be removed.