> For the complete documentation index, see [llms.txt](https://docs.imerit-prod.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.imerit-prod.io/annotation-tool/key-features/cuboid-grouping.md).
# Cuboid Grouping
Cuboid Grouping allows users to link multiple cuboids that move together in the real world—maintaining their relative positions throughout a sequence. This is particularly useful when tracking objects that are physically connected or consistently aligned. The grouping helps improve annotation accuracy, ensures spatial consistency, and reduces the need for manual frame-by-frame adjustments. It’s a good and lean feature, enhancing both annotation quality and workflow efficiency without adding complexity.
{% hint style="success" %} Useful when tracking objects that are physically connected or consistently aligned.
{% endhint %}
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## Use Case
* **Agri-Tech – Tractor with a Towed Implement**\
Grouping ensures the implement maintains a fixed offset behind the tractor across the sequence, saving time and reducing annotation drift.
* **Autonomous Driving – Cabin and a Trailer**\
Helps track multi-part vehicles moving together while preserving their orientation and spacing.
***
## Benefits
* **Good**: Maintains consistent spatial relationships between grouped cuboids, improving annotation accuracy across frames.
* **Lean**: Reduces manual alignment work, especially in sequences where linked objects appear across long spans.
* **Flexible**: Grouping can be applied and ungrouped selectively over any frame range, offering precise control.
***
## Steps to Use Cuboid Grouping
1. Multi-select cuboids to be grouped by holding down the Ctrl key.
2. Hover over the cuboid that should lead the group, then right-click (contextual click).
3. Choose ‘Group’ from the context menu.
* The grouping feature will confirm the range and prevent the user from providing a range where both annotations are not present.
4. Click on an individual cuboid within the group to view the orthogonal view.
* These orthogonal views are read-only as long as the cuboid is grouped.
5. To ungroup:
* Navigate to the frame where the grouping should end.
* Right-click the lead cuboid and select ‘Ungroup’.
* The ungroup will confirm the range the ungrouping action should be applied to.
> **Tip:** Use grouping to avoid drift and rework when dealing with attached or coordinated objects that stay aligned throughout a sequence.
Useful when tracking objects that are physically connected or consistently aligned.
{% endhint %}
