Documentation
  • Introduction
  • Tutorials
    • Getting started
    • Python SDK quickstart
    • Model-assisted labeling
  • How to annotate
    • Label images
      • View and navigate in the image interfaces
      • Image interface settings
      • Image segmentation interface
      • Image vector interface
    • Label 3D point clouds
      • View and navigate in the 3D interface
      • Upload, view, and overlay images
      • 3D interface settings
      • 3D point cloud cuboid interface
      • 3D point cloud vector interface
      • 3D point cloud segmentation interface
      • Merged point cloud view (for static objects)
      • Batch mode (for dynamic objects)
      • Smart cuboid propagation
      • 3D to 2D Projection
      • Tips for labeling cuboid sequences
    • Label sequences of data
      • Use track IDs in sequences
      • Use keyframe interpolation
    • Annotate object links (beta)
    • Customize hotkeys
  • How to manage
    • Add collaborators to a dataset
    • Create an organization
    • Configure the label editor
    • Customize label queue
    • Search within a dataset
    • Clone a dataset
    • Work with issues
    • Bulk change label status
    • Manage QA processes
  • How to integrate
    • Import data
      • Cloud integrations
    • Export data
      • Structure of the release file
      • Exporting image annotations to different formats
    • Integrations
      • Hugging Face
      • W&B
      • Databricks
      • SceneBox
    • Create an API key
    • Upload model predictions
    • Set up webhooks
  • Background
    • Main concepts
    • Sequences
    • Label queue mechanics
    • Labeling metrics
    • 3D Tiles
    • Security
  • Reference
    • Python SDK
    • Task types
    • Sample formats
      • Supported file formats
    • Label formats
    • Categories and attributes
    • API
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On this page
  • General tips
  • Use your GPU in Chrome for better performance
  • Label object by object
  • Use hotkeys for fine adjustments
  • Learn about keyframes and remove-keyframes
  • How to find objects
  • How to label a static object
  • Use an is_static attribute
  • How to label a dynamic object
  • How to label a static object that starts moving

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  1. How to annotate
  2. Label 3D point clouds

Tips for labeling cuboid sequences

This page describes some tips and tricks to label cuboids in point cloud sequences faster.

Previous3D to 2D ProjectionNextLabel sequences of data

Last updated 4 months ago

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General tips

Use your GPU in Chrome for better performance

to make sure the 3D point cloud interface runs smoothly.

Label object by object

By labeling object by object, we mean first labeling an object in the whole sequence, before moving on to the next object. This is typically easier and faster than labeling all objects on the first frame, then all objects on the second frame, and so on.

Use hotkeys for fine adjustments

Your mouse is perfectly suitable for quickly drawing a cuboid or for moving it to roughly the right position. However, for fine adjustments, you’re probably better off using your keyboard. Segments.ai has hotkeys for almost everything, including for and for . Better still, you can customize all the hotkeys to your liking:

Learn about keyframes and remove-keyframes

is enabled by default on point cloud sequences with cuboid annotations. It allows you to label a sequence perfectly by only labeling a few “key” frames, while the rest of the frames are completed automatically. On Segments.ai, there are also remove-keyframes that indicate when an object disappears. More precisely, a remove-keyframe means that the object is not present in that frame and all frames before the next normal keyframe.

You can learn about adding, moving, and removing keyframes on this page:

How to find objects

In order to find objects to label, you can use the main point cloud viewer. You can move through the interface either by using your mouse or the hotkeys (w, a, s, d by default). Learn more about navigating the 3D scene on the following page:

If the point cloud sequence has images associated with it, they can often be helpful for locating objects that might otherwise be hard to spot in the point clouds. Learn more about using images in the 3D interface on the following page:

How to label a static object

  1. Go to the first frame where the static object is visible.

  2. Disable the merged point cloud view.

  3. Go through the sequence to find the frame where the object disappears.

Use an is_static attribute

Add an is_static track-level attribute to the categories that can be static (see Configure the label editor). When this attribute is checked, you can edit the position/dimensions/rotation of a cuboid in one frame, and these changes will be applied to all other frames automatically.

How to label a dynamic object

  1. Go to the first frame where the static object is visible.

  2. Go through the sequence to find the last frame where the object is visible.

  3. When the sequence is roughly labeled, go through the sequence by using the arrow keys and make fine adjustments using keyboard hotkeys.

How to label a static object that starts moving

Labeling a static object that starts moving is basically the same as labeling a dynamic object. To label the static part:

  1. Place a keyframe on the first frame where the object is static.

This way, you make sure that the object remains static between the keyframes.

view if it is available.

around the object.

Tip: you can use the for navigating through a sequence faster.

in the frame where the object disappears.

around the object.

to the correct position.

in the frame where the object disappears.

.

Adjust the object in the frames where the cuboid’s position is the farthest away from the real object’s position. Keyframe interpolation will interpolate the object linearly in the frames in between. If the object does not move linearly, use to propagate the cuboid automatically.

.

Add a keyframe to the last frame where the object is static ().

View and navigate in the 3D interface
Upload, view, and overlay images
batch mode
smart propagation
Use your GPU in Chrome
Customize hotkeys
Use keyframe interpolation
by double-clicking under the frame
An example of keyframes (blue diamonds) and a remove-keyframe (grey circle with cross).
Use the merged point cloud view to see the full dimensions of a static object.
Use batch mode to quickly adjust a cuboid in a point cloud sequence.
Merged point cloud view
Open the batch mode
Close the batch mode
Toggle the merged point cloud
Draw a cuboid
Remove the cuboid
Draw a cuboid
Move the cuboid
Remove the cuboid
moving a cuboid
changing its dimensions
Keyframe interpolation