Slamcore Session Explorer

Warning

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 support@slamcore.com, 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.

The Slamcore Session Explorer provides a visual interface to interact with the session map saved from the SLAM runs. It can be used to view information about the map loaded, view or update a height or occupancy map and export the map.

Note

To use the Session Explorer, you must first create a session containing a height/occupancy map, according to the 2D Occupancy Mapping Tutorial.

Usage

To launch the Session Explorer tool, run:

$ slamcore_session_explorer

On the top menu bar, select File and Open and choose the .session file to load.

Fig. 15 Slamcore Session Explorer - User Interface

On the Left Sidebar, choose between the Height Map and Occupancy Map channels to view the respective maps.

For navigation purposes, the occupancy map might need manual editing to fill in unmapped areas and/or remove or add obstacles. The Slamcore Session Explorer tool allows you to update the occupancy map in the session file.

With the Occupancy Map channel selected, you may tweak the occupancy map extraction method using the From height map button.

Alternatively, you may edit the pixels manually. First, Select File and Export occupancy png. Edit the 8-bit Grayscale PNG in an external image editing tool (e.g. GIMP - Use the Pencil Tool). Then using the blue From File button in the Session Explorer Tool, import the edited map image to replace the existing one in the session file.

Warning

The Session Explorer tool does not support other image formats, a different image size or resolution, soft edges, or additional colours and values.

Once satisfied with the map, select File and Save .session to save the session map, which can be used in ROS for navigation.

Note

More description regarding the methods and options is given in The Application Section, and a detailed tutorial is provided in 2D Occupancy Mapping to guide you through the process of preparing the occupancy map for navigation use.

The Application

Fig. 16 Slamcore Session Explorer - Menus

Top Menu Bar

File:

Open: Open a .session file that contains a height map
Save .session: Save a session file after updating the map
Export occupancy png: Export a .png occupancy map image
Export height ply: (Experimental Feature) Export the height map as a .ply file, which can be viewed 3D programs such as MeshLab.
Quit: Quit the application.

View:

Camera: Orbit view enables 3D camera control, while Top Down view gives an aerial view of the map.
Fit in Window: Reset the map to fit in the viewer window.

Help:

Control: Description of the keyboard and mouse controls for the application.
Settings: Show a square grid and change the grid size (width) and cell size (spacing).
About: Version and licensing information.

Left Sidebar

Displays information of the session file and map loaded.

Information

Session Information:

Filename: Session Filename
Date: The date and time at which the session was saved.
Dataset Name: Name of the dataset that the session was generated from.

Map Information:

Storage: Storage size of the map.
Estimated Area: Estimated mapped area.
Resolution: Map resolution or the size in metres of each cell.
Map Dimensions: The length and width of the map against the square grid.

Select channel to display

View the Height Map or the Occupancy Map.

Height Map

Displays the height map in 2D or 3D.

Occupancy Map

Displays the 2D occupancy map and options for map replacement. This allows users to manually tweak the map based on their knowledge of the physical space.

From height map: Choose and tune the map extraction method.
- Gradient Method (Default): Extracts the occupancy map based on the gradient of the reconstructed surface. Gradient of the surface can be considered as a proxy for surface traversability and can be different for different types of robots. It is particularly advantageous when mapping in environments that are not entirely flat, as it can handle small slopes and surface unevenness well. We recommend using this method in general. The gradient threshold is dimensionless and can be adjusted with the slider.
- Height Method: Extracts the occupancy map by placing a threshold on the height from the detected ground plane. The floor threshold is reported in metres and can be adjusted with the slider.
From file: Update the session file by importing an edited occupancy map image. The imported image must be an 8-bit Grayscale PNG containing only three colours:
- Occupied Pixel: Black RGB(0, 0, 0)
- Free Pixel: White RGB(255, 255, 255)
- Unknown Pixel: Grey RGB(128, 128, 128)
Reset: Discard changes and reset the occupancy map to its default.

Command-Line Options

At start-up, the Slamcore Session Explorer accepts the following command-line options:

-h,--help: Print this help message and exit

-l,--load-session :FILE: Path to the .session file to load