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GAEMI Loci

Map Merging

Map merging combines an existing HD Map (target map) and an additional map (source map) into a single map. When an incorrect registration occurs during Map Aggregation and the map is broken, the user visually identifies the issue, manually loads the maps to combine, and merges them.

Incorrect registration — map damaged due to a failed registration during Map Aggregation

Workflow

  1. Visually inspect the map that Map Aggregation loaded automatically to check for incorrect registration, then click the Clear button to reset the map.

    Clear button — location of the button that resets an incorrectly registered map

  2. In the left panel, click the Load Map button to load the existing HD Map {site_name}/{local_time}/hd_map/original/original_hd_map.bin.zst.

    Load Map button — location of the button that loads the existing HD Map Load Target Map dialog — selecting the original_hd_map.bin.zst file

  3. In the left panel, click the Load Source Map button to load the additional map to merge {site_name}/{local_time}/hd_map/original/addition_map.bin.zst.

    Load Source Map button — location of the button that loads the additional map to merge Load Source Map dialog — selecting the addition_map.bin.zst file Source Map loaded — Target Map and Source Map displayed together

  4. In the overlapping area between the target map and the source map, Ctrl + right-click the reference keyframe and click Set as Target (Red).

  5. Ctrl + right-click the keyframe at the same location on the source map, then click Set as Source (Green).

  6. Toggle the gizmo mode with the T / R keys, then hold Ctrl and drag the gizmo to manually adjust the source keyframe’s position and orientation.

    • T: Translate / R: Rotate

  7. Perform fine alignment with Run ICP.

    • Noise Scale: noise value of the Between Factor (default: 0.01, range: 0 to 1)
    • Max Distance: maximum correspondence distance (default: 5.0 m, range: 0 to 10)

  8. Click Add Loop Factor (links a keyframe from the target map with one from the source map).

    • Repeating this for multiple pairs improves alignment accuracy.

  9. Optimize the map with the Run Optimization button.

  10. Review the result, then click Save As to create the {site_name}/{local_time}/hd_map/edited/ folder and save the map there.

Typical Workflow

[Map merging workflow]
1. Identify an incorrectly registered map → [Clear] → reset the map
2. [Load Map] → load the existing HD Map (original_hd_map.bin.zst)
3. [Load Source Map] → load the additional map (addition_map.bin.zst) to merge
4. Ctrl + right-click in the overlapping area → Set as Target (Red)
5. Ctrl + right-click on the source map → Set as Source (Green)
6. Toggle gizmo mode with T / R, then Ctrl + drag to adjust position/orientation
7. [Run ICP] → fine alignment
8. [Add Loop Factor] → link keyframes (repeat for multiple pairs)
9. [Run Optimization] → optimize the map
10. Review the result, then [Save As] → create and save into {site_name}/{local_time}/hd_map/edited/

Saving the Map

Corrected maps are saved in Boost serialization + Zstandard compression format (.bin.zst).

  1. In the left panel, click the Save As button. Location of the Save As button
  2. From the {site_name}/{local_time}/hd_map/ path, click the create-folder button. Save Map To dialog — click the create-folder button in the hd_map path
  3. Enter the folder name edited and click the Create button. Click Create after entering the folder name edited
  4. Select the newly created edited folder and click Select This Folder to save. Select the edited folder and click Select This Folder to save