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.

Useful when tracking objects that are physically connected or consistently aligned.

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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

Select the cuboids to be grouped by holding down the Ctrl key and multi-selecting each cuboid.

2

Choose the lead cuboid

Hover over the cuboid that should lead the group, then right-click (contextual click) and choose “Group” from the context menu.

• The grouping feature will confirm the range and prevent selecting a range where both annotations are not present.

3

View orthogonal

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.

4

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.