Trackables pane

Main Page → Trackables pane

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Rigid Body Refinement

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New in Motive 2.0

Using the RigidBody Refinement tool for improving asset definitions.

Rigid body refinement tool improves the accuracy of rigid body calculation in Motive. When a rigid body asset is initially created, Motive references only a single frame for defining the rigid body definition. The rigid body refinement tool allows Motive to collect additional samples in the live mode for achieving more accurate tracking results. More specifically, this feature improves the calculation of expected marker locations of the rigid body as well as position and orientation of the rigid body itself.

This feature is supported in Live Mode only.

Follow the below steps to refine rigid body definition in Motive:

Refinement Steps

1. Under Tools tab open the Trackables pane.
2. In Live mode, select an existing rigid body asset that you wish to refine.
3. Hold the selected rigid body at the center of the capture volume so that as many cameras as possible can clearly capture the markers on the rigid body.
4. Under the Refine Samples entry, Set the number of sample frame that you wish to capture for the refining process.
5. Press Start Refine in the Trackables pane and the
6. Slowly rotate the rigid body to collect samples ranging rigid body orientations.
7. Once all necessary samples are collected, the refinement results will be displayed.

Rigid body refinement feature

HMD Calibration

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New in Motive 2.0

The HMD calibration feature allows you to calibrate an HMD rigid body so that its pivot point is placed right at the proper location for VR applications, precisely.

The HMD calibration feature supports Oculus HMDs only. This feature works only in Live mode.

Using the HMD Calibration Tool (Passive Markers)

Calibration of HMDs with passive markers utilizes both the OptiTrack mocap system and the Oculus Tracker for precisely calculating the location of the pivot point of an Oculus HMD. When using this feature, both systems must be tracking the HMD rigid body.

1. Connect the Oculus Tracker and have the Oculus software running in the background.
2. Launch Motive.
3. [Motive] Create a rigid body asset from the markers on the oculus HMD. Read: Creating Rigid Body.
4. [Motive] Open the Trackables pane. Tools → Trackables → HMD Calibration tab
5. [Motive] Select the HMD rigid body. Under Detected Type, it should indicate Custom RigidBody.
6. [Motive → Trackables pane] Set the desired number of sample counts (Default: 750) and the desired orientation.
7. [Motive → Trackables pane] Press start to initiate the sampling process.
8. [Motive → Trackables pane] During calibration, make sure both the mocap system and the Oculus Tracker is tracking the HMD.
9. [Motive → Trackables pane] Once it starts collecting the samples, point the HMD towards the Tracker and slowly rotate it and sample different orientations.
10. [Motive → Trackables pane] When it finishes collecting samples, it will display the offset distance, in mm, between pivot point position detected by oculus and the motion capture system.
11. [Motive → Trackables pane] If the results are satisfying, press Apply to calibrate the HMD rigid body.

Using the HMD Calibration Tool (Active HMD Clips)

For calibration of HMDs with active HMD clips can be easily done by following the below steps. It utilizes known marker configurations to precisely locate appropriate pivot point position and orientation. Oculus tracker is not required for this.

1. First of all, make sure Motive is configured for active marker tracking.
2. In Live mode, select the active markers on the HMD clip and define a rigid body.
3. Under Tools tab open the Trackables pane and access the HMD calibration tab.
4. Hold the selected rigid body at the center of the capture volume so that as many cameras as possible can clearly capture the markers on the HMD clip.
5. Select the active HMD clip rigid body in Motive.
6. Make sure Detected Type shows up as OptiTrack Active HMD clip.
7. Under the Samples Counts entry, assign a number of sample frames that you wish to capture for calibration
8. Select the desired orientation of the rigid body. You can select from +Z forward (Unity), +X forward (Unreal), or -Z forward (Native)
9. Press Start to start the calibration process.
10. Slowly rotate the HMD to collect samples in diverse orientations.
11. Once all necessary samples are collected, it will report the calibration result.
12. If everything looks good, press Apply Calibration, and the HMD rigid body pivot point will be calibrated to given orientation.