Brush Sphere

Paintbrush 3D is a tool used in 3D point cloud annotation that allows annotators to "paint" over specific areas of the 3D space.

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Use Case

• Segmentation: By painting over regions in the 3D point cloud, annotators can label areas of interest more intuitively.

• Freeform Annotation: It provides flexibility to annotate irregular shapes or areas that are hard to capture with rigid tools like cuboids or polylines.

• Efficiency: Allows for faster labeling of large or complex surfaces within a 3D environment.

The 3D paintbrush is particularly useful for annotating non-rectangular objects like vegetation, terrain, or other organic forms in 3D data.

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Create Segment

1

Start

Click on the '+' icon of the class from the class list.

An "i" icon appears on the header to aid the user with the controls.

2

Position the Sphere

Hover the mouse over the drawing area, and a gray circle will appear — this is the sphere tool which also has the same depth.

• The points inside the paintbrush will tint to yellow to provide a clear visual indication that the points will get segmented when the annotation begins.

3

Resize the Sphere

To increase/decrease the size of the sphere, hold down CTRL and rotate the mouse wheel.

4

Paint

To begin annotating, hold the left mouse button and drag over the points. The points that were yellow will get segmented to the class color immediately.

5

Save

Once all points belonging to the class are segmented, right-click to save the annotation. The Annotation details pop-up will appear.

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Delete a Segment

To un-segment points:

• Click on any ‘+’ against a class, hold ALT and hover over points. The points inside the paintbrush will tint red to denote that these points will be un-segmented.

• While keeping the ALT key pressed, left click and drag the mouse to un-segment.

• To save, right-click.