Main Page → Motive Documentation → Labeling
This page provides basic description of marker labels and instructions on labeling workflow in Motive.
After editing marker data in a recorded Take, corresponding Solved Data must be updated.
There are two approaches to labeling markers in Motive:
For tracking rigid bodies and skeletons, Motive can use the asset definitions to automatically label associated markers both in real-time and post-processing. The auto-labeler uses references assets that are enabled, or assets that are checked in the Assets pane, to search for a set of markers that matches with the definition and assign pre-defined labels throughout the capture.
There are times, however, when it is necessary to manually label a section or all of a trajectory, either because the markers of a rigid body or a skeleton were misidentified (or unidentified) during capture or because individual markers need to be labeled without using any tracking assets. In these cases, the Labeling pane in Motive is used to perform manual labeling of individual trajectories. Manual labeling workflow is supported only in post-processing of capture when a Take file (TAK) has been loaded with 3D data as its playback type. In case of 2D data only capture, the Take must be Reconstructed first in order to assign, or edit, the marker labels in its 3D data. This manual labeling process, along with 3D data editing is typically referred to as post processing of mocap data.
Rigid body and skeleton asset definitions contain information of marker placements on corresponding assets. This is recorded when the assets are first created, and the auto-labeler in Motive uses them to label a set of reconstructed 3D trajectories that resemble marker arrangements of active assets. Once all of the markers on active assets are successfully labeled, corresponding rigid bodies and skeletons get tracked in the 3D viewport.
The auto-labeler runs in real-time during Live mode and the marker labels get saved onto the recorded TAKs. Running the auto-labeler again in post-processing will basically attempt to label the rigid body and skeleton markers again from the 3D data.
Note: Be careful when reconstructing a Take again either by Reconstruct or Reconstruct and Auto-label, because it will overwrite the 3D data and any post-processing edits on trajectories and marker labels will be discarded. Also, for Takes involving skeleton assets, the recorded skeleton marker labels, which were intact during the live capture, may be discarded, and reconstructed markers may not be auto-labeled again if the skeletons are never in well-trackable poses throughout the captured Take. This is another reason why you want to start a capture with a calibration pose (e.g. T-pose).
Markerset is a list of labels, or marker names, that can be manually assigned to unlabeled markers. This can be created when there is a need to label individual markers in the scene that are not associated with a rigid body nor a skeleton asset.
Labels in the markerset, rigid body, and skeleton assets are managed using the Constraints pane. Please refer to the Constraints pane to see how to add and/or modify marker labels. Once the labels are added, Labeling pane can be used to assign them onto markers.
Read more at Constraints pane page.
The Labeling pane is used to assign, remove, and edit marker labels in the 3D data. The Tracks View under the Graph View pane can be used in conjunction with the Labeling pane to monitor which markers and gaps are associated. The Labeling pane is also used to examine the number of occluded gaps in each label, and it can be used along with the Editing Tools for complete post-processing.
Using the Labeling pane, you can assign marker labels for each asset (MarkerSet, Rigid Body, and Skeleton) via the QuickLabel Mode . The Labeling Pane also shows a list of labels involved in the Take and their corresponding percent completeness values. The percent completeness values indicate frame percentages of a Take for which the trajectory has been labeled. If the trajectory has no gaps (100% complete), no number will be shown. You can use this pane together with the Graph View pane to quickly locate gaps in a trajectory.
For a given frame, all labels are color-coded. For each frame of 3D data, assigned marker labels are shown in white, labels without reconstructions are shown in red, and unlabeled reconstructions are shown in orange; similar to how they are presented in the 3D View.
See the Labeling Pane page for detailed explanation on each option.
The QuickLabel mode allows you to tag labels with single-clicks in the view pane, and it is a handy way to reassign or modify marker labels throughout the capture. When the QuickLabel mode is toggled, the mouse cursor switches to a finger icon with the selected label name attached next to it. Also, when the display label option is enabled in the perspective view, all of assigned marker labels will be displayed next to each marker in the 3D viewport, as shown in the image below. Select the marker set you wish to label, and tag the appropriate labels to each marker throughout the capture.
When assigning labels using the Quick Label Mode, the labeling scope is configured from the labeling range settings. You can restrict the labeling operation to apply from the current frame backward, current frame forward, or both depending on the trajectory. You may also restrict labeling operations to apply the selected label to all frames in the Take, to a selected frame range, or to a trajectory 'fragment' enclosed by gaps or spikes. The fragment/spike setting is used by default and this best identifies mislabeled frame ranges and assigns marker labels. See the Labeling pane page for details on each feature.
Hiding Marker Labels
The following section provides the general labeling steps in Motive. Note that the labeling workflow is flexible and alternative approaches to the steps listed in this section could also be used. Utilize the auto-labeling pipelines in combination with the Labeling pane to best reconstruct and label the 3D data of your capture.
Step 1. In the Data Management pane, Reconstruct and auto-label the take with all of the desired assets enabled.
Step 2. In the Graph View pane, examine the trajectories and navigate to the frame where labeling errors are frequent.
Step 3. Open the Labeling pane.
Step 4. Select an asset that you wish to label.
Step 5. From the label columns, Click on a marker label that you wish to re-assign.
Step 6. Inspect behavior of a selected trajectory and its labeling errors and set the appropriate labeling settings (allowable gap size, maximum spike and applied frame ranges).
Step 7. Switch to the QuickLabel mode (Hotkey: D).
Step 8. On the Perspective View, assign the labels onto the corresponding marker reconstructions by clicking on them.
Step 9. When all markers have been labeled, switch back to the Select Mode.
Step 1. Start with 2D data of a captured Take with model assets (skeletons and rigid bodies).
Step 2. Reconstruct and Auto-Label, or just Reconstruct, the Take with all of the desired assets enabled under the Assets pane. If you use reconstruct only, you can skip step 3 and 5 for the first iteration.
Step 3. Examine the reconstructed 3D data, and inspect the frame range where markers are mislabeled.
Step 4. Using the Labeling pane, manually fix/assign marker labels, paying attention to your label settings (direction, max gap, max spike, selected duration).
Step 5. Unlabel all trajectories you want to re-auto-label.
Step 6. Auto-Label the Take again. Only the unlabeled markers will get re-labeled, and all existing labels will be kept the same.
Step 7. Re-examine the marker labels. If some of the labels are still not assigned correctly from any of the frames, repeat the steps 3-6 until complete.
The general process for resolving labeling error is:
For more data editing options, read through the Data Editing page.
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