Overview

This page provides instructions on configuring the active components, Active Tags and/or Active Pucks, that are equipped with inertial measurement unit (IMU) sensors. By fusing the optical tracking data of the active markers with the IMU data, Motive can further stabilize the rotational tracking of the Rigid Bodies and accommodate for tiny jitters throughout the tracking. This is recommended for applications where the stability of rotation tracking data is important, including tracking cameras in virtual production applications, tracking drones in low camera-count setups, and more.

Requirements

• Motive version 2.2 to 2.3.1

• IMU Active Batch Programmer

• Base Station: Firmware 2.2.2 or above

• IMU Active Tags/Pucks: Firmware 2.2.1 or above

Additional Information

• When configured, each Active Base Station can communicate with up to 7 IMU Tags/Pucks.

• When needed, multiple Base Stations can be plugged into the same camera network; as long as they are communicating through a separate channel.

• To use the IMU components, all of the devices, including the Base Station, must have firmware version 2.x or above installed. Please follow the instruction below to check the firmware versions on each device.

Active Component Setup

For the IMU data to be used for tracking in Motive, unique Uplink IDs must be assigned onto each IMU Tag or Puck using the active batch programmer program. Then, the Uplink IDs will need to be inputted under the properties of the corresponding Rigid Bodies in Motive. Please follow the steps below:

1) Download Active Batch Programmer

Use the following link to download the batch programmer used for 2.x firmware. Once downloaded, unzip the downloaded file and launch the EXE file.

• Batch Programmer Download:

• OptiTrack Downloads: Active Batch Programmer

2) Check the firmware version and existing configuration

Before setting up the components, we will want to check the existing configurations on the Base Station, Tags, and/or Pucks. To check this, enable the ‘’Read-Only Mode’’ check box at the bottom-left corner of the active batch programmer, and then connect the devices one at a time via USB. Each time a new active component is detected, existing configurations including the firmware version will get listed under the Log section. If any of the settings do not meet the below requirements, you can re-configure them in the next step.

Firmware Version

In order to use IMU Tags/Pucks, all of the active components must have firmware version 2.2.x or above installed. Please check the firmware version on the active components. If the installed firmware is an older version, please contact us for assistance with upgrading the firmware.

RF Channel

Please make sure that all of the active components are communicating through the same channel. Check this and take a note of the channel value as this will also need to be inputted into Motive for IMU data. The RF channel can be set anywhere between 11-26.

Label

The Labels are active IDs assigned to each marker, and it's important that there are no overlapping labels, or IDs, assigned to the same batch of active Tags/Pucks. This setting is applicable to Active Tags/Pucks only.

After checking the settings, you can unplug the device and connect the next one to check the settings.

3) Configure the settings in the Active Batch Programmer

Now that we understand the existing configurations and what needs to be changed, we can configure the active components. To do this, disable the Read-Only Mode in the batch programmer, and settings configured in the IMU batch programmer will get applied to each newly connected device. Please note that this could also reset the existing configuration, thus, make sure to configure only the settings that need to be changed.

Configure Uplink ID

For IMU Tags or Pucks, unique Uplink IDs need to be assigned for each of them. For doing this, simply check the box next to the Uplink ID whenever we are configuring IMU Tags or Pucks.

RF Channel/Label

Uncheck the boxes next to "Set marker labels" and "Set radio options" unless they also need to be reconfigured.

All of the Tags/Pucks are pre-configured for every set of devices that gets shipped out in the same order, and we also make sure none of the Labels overlap. Thus, users should not need to use this batch programmer in general. The cases when you would want to reconfigure the active components are: 1) When you have purchased new Tags/Pucks to add to the system from the previous order. 2) When there is a need to change the RF communication channel to avoid interferences.

In cases where marker labels or RF channels need to be reconfigured, enable the box next to the corresponding setting in the batch programmer. DO NOT check the box unless the settings need to be changed. When reconfiguring marker labels, ALL of the Tags and Pucks will need to be reconfigured at once, so that the labels do not overlap with other components in the system.

4) Connect an active component

Once we have configured the settings in the batch programmer, connect Active Tags or Pucks one at a time and the programmer will apply the configured settings to the newly connected device, and it will also make sure that the IDs do not overlap in the same batch. Once the settings get applied the details will get listed under the Log.

It’s recommended to note the assigned Uplink IDs for each Tag/Puck so that we can track down the settings easily when needed.

5) Disconnect and connect remaining devices

Once a device is configured, disconnect and connect the next device to apply the same settings and unique IDs. Repeat this for all of the active components that need to be configured.

Tag Attachment to Tracked Objects

When using an IMU Active Tag to create a custom Rigid Body, please make sure both the PCB board of the tag and the LEDs are securely attached and rigidly constrained to the object. The IMU sensor fusion will not work correctly if either the markers or the tag are not secured to the rigid object.

Motive Setup

Now that each of the IMU Tags/Pucks has been assigned with an Uplink ID, the next step is to input this ID into the properties of the corresponding Rigid Bodies in Motive. Also, the RF channel configured for each active component will need to be inputted as well. Follow the below steps to assign Active Tag ID and Active RF Channel property for each Rigid Body:

1) Launch Motive

Make sure the configured Active Base Station is connected to the camera system and launch Motive.

2) Power the IMU Tag/Puck

Click the power button on the Tag/Puck to start the device. When the Tag/Puck first initializes, the status LEDs will start blink in red and orange rapidly. This indicates that the IMU sensor is attempting to initialize. At this stage, keep the IMU Tag/Puck stationary until the status LED blinks in green indicating that it has completed the initialization.

3) Create a Rigid Body

Select the active markers associated with a Tag/Puck and create a Rigid Body.

4) Access advanced rigid properties

Open the Properties pane and select the Rigid Body. Reveal the advanced properties by clicking on "..." menu at the top-right and selecting Show Advanced.

5) Input IMU Properties: Active Tag ID and RF Channel

Scroll down to find the IMU section and input the "Uplink ID" value for the corresponding Tag/Puck into. Additionally, input the "RF Channel" used the the corresponding Base Station. Once this is completed the Rigid Body should have the correct properties set to use the IMU in the tag. You can also adjust the Sensor Fusion property to balance the contribution between optical tracking data and IMU data for the Rigid Body solve.

6) Check the status

At this point, the IMU Tags and Pucks are ready to be used. The color of the Rigid Body indicates the status of the IMU data stream.

IMU's per BaseStation

BaseStations are only capable of hosting a finite number of IMUs based on the speed of the framerate in Motive.

Below is a table depicting how many IMUs are able to connect per a single BaseStation at varying framerates. BaseStations have 16 radio frequency (RF) channels for use (11-26). Therefore, when adding more than one BaseStation to a system, the IMU count is simply the number of IMUs below multiplied by the number of BaseStations up to 16. For example, if you have 4 BaseStations and you're running at 90Hz, the number of allowable IMUs would be 60 (15*4=60).

This page briefly goes over the active finger marker set and how it needs to be set up.

Overview

The active finger Marker Set utilizes the tracking capability of active markers and its active labeling features to accomplish tracking of both the hands and the fingers. These Marker Sets require the active marker tracking solution and the Tag(s). Wired from an active Tag, each active marker must attach to the expected locations. For each hand, 10 active markers are needed for each hand.

Requirements

• The Active Base Station

• Active Tag(s) with active markers.

• A way to attach active markers onto the hands (e.g. gloves).

Below Marker Sets uses active finger tracking

• Baseline + Active Fingers (57)

• Core + Active Fingers (62)

• Right Hand + Active Fingers (10)

• Left Hand + Active Fingers (10)

Marker Placement

• Total 10 markers will be attached on each hand (8 Active markers and 2 passive)

• Tags: Attach Tags to each hand for the active LEDs.

• Passive Markers (2): Attach the 2 passive markers to both sides of the wrist, you'll want them on the joints of either side along the wrist flexion point.

• Active Markers (8): Each Tag connects up to 8 active markers. Position the wired active markers at the tip of all five fingers (5), one each on the knuckle of the index finger and the pinky finger (2), and lastly, place the remaining active marker on the inside of the bottom thumb joint.

Creating the hand

Steps for creating an active finger Marker Set is the same as the other skeleton Marker Set:

1. Open the Builder pane and select the desired hand Marker Set under the drop-down menu.

2. Make sure all of the markers are placed in the correct positions. For the Core + Active Fingers (62) Marker Set, please make sure the passive full body tracking markers are also placed on the person's body.

3. Once the markers have been placed, ask the subject to strike the calibration pose.

4. Select the finger markers in the 3D viewport.

5. The Marker Detected must match Marker Required in the Builder pane.

6. Click Create.

This page provides instructions on how to set up and use the OptiTrack active marker solution.

Overview

The OptiTrack Active Tracking solution allows synchronized tracking of active LED markers using an OptiTrack camera system. Consisting of the Base Station and the users choice Active Tags that can be integrated in to any object and/or the "Active Puck" which can act as its own single Rigid Body.

Connected to the camera system the Base Station emits RF signals to the active markers, allowing precise synchronization between camera exposure and illumination of the LEDs. Each active marker is now uniquely labeled in Motive software, allowing more stable Rigid Body tracking since active markers will never be mislabeled and unique marker placements are no longer be required for distinguishing multiple Rigid Bodies.

Hardware Setup

Required Component

BaseStation

Sends out radio frequency signals for synchronizing the active markers.

• Powered by PoE, connected via Ethernet cable.

• Must be connected to one of the switches in the camera network.

Active Marker Options

Active Tag

• Connects to a USB power source and illuminates the active LEDs.

• Receives RF signals from the Base Station and correspondingly synchronizes illumination of the connected active LED markers.

• Emits 850 nm IR light.

• 4 active LEDs in each bundle and up to two bundles can be connected to each Tag.

• (8 Active LEDs (4(LEDs/set) x 2 set) per Tag)

• Size: 5 mm (T1 ¾) Plastic Package, half angle ±65°, typ. 12 mW/sr at 100mA

Active Pucks

An active tag self-contained into a trackable object, providing information with 6 DoF for any arbitrary object that it's attached to. Carries a factory installed Active Tag with 8 LEDs and a rechargeable battery with up to 10-hours of run time on a single charge.

Wiring the Components

Camera System

• Active tracking is supported only with the Ethernet camera system (Prime series or Slime 13E cameras). For instructions on how to set up a camera system see: Hardware Setup.

BaseStation

• Connects to one of the PoE switches within the camera network.

• For best performance, place the base station near the center of your tracking space, with unobstructed lines of sight to the areas where your Active Tags will be located during use. Although the wireless signal is capable of traveling through many types of obstructions, there still exists the possibility of reduced range as a result of interference, particularly from metal and other dense materials.

• Do not place external electromagnetic or radiofrequency devices near the Base Station.

• When Base Station is working properly, the LED closest to the antenna should blink green when Motive is running.

Tag Setup

• Connect two sets of active markers (4 LEDs in each set) into a Tag.

• Connect the battery and/or a micro USB cable to power the Tag. The Tag takes 3.3V ~ 5.0V of inputs from the micro USB cable. For powering through the battery, use only the batteries that are supplied by us. To recharge the battery, have the battery connected to the Tag and then connect the micro USB cable.

• To initialize the Tag, press on the power switch once. Be careful not to hold down on the power switch for more than a second, because it will trigger to start the device in the firmware update (DFU) mode. If it initializes in the DFU mode, which is indicated by two orange LEDs, just power off and restart the Tag. To power off the Tag, hold down on the power switch until the status LEDs go dark.

• Once powered, you should be able to see the illumination of IR LEDs from the 2D reference camera view.

Puck Setup

• Press the power button for 1~2 seconds and release. The top-left LED will illuminate in orange while it initializes. Once it initializes the bottom LED will light up green if it has made a successful connection with the base station. Then the top-left LED will start blinking in green indicating that the sync packets are being received.

• For more information, please read through the Active Puck page.

Motive Settings

Active Patten Depth

Settings → Live Pipeline → Solver Tab with Default value = 12

This adjusts the complexity of the illumination patterns produced by active markers. In most applications, the default value can be used for quality tracking results. If a high number of Rigid Bodies are tracked simultaneously, this value can be increased allowing for more combinations of the illumination patterns on each marker. If this value is set too low, duplicate active IDs can be produced, should this error appear increase the value of this setting.

Minimum Active Count

Settings → Live Pipeline → Solver Tab with Default value = 3

Setting the number of rays required to establish the active ID for each on frame of an active marker cycle. If this value is increased, and active makers become occluded it may take longer for active markers to be reestablished in the Motive view. The majority of applications will not need to alter this setting

Active Marker Color

Settings → Views → 3D Tab with Default color = blue

The color assigned to this setting will be used to indicate and distinguish active and passive markers seen in the viewer pane of Motive.

Camera Settings

For tracking of the active LED markers, the following camera settings may need to be adjusted for best tracking results:

Camera Exposure

For tracking the active markers, set the camera exposures a bit higher compared to when tracking passive markers. This allows the cameras to better detect the active markers. The optimal value will vary depending on the camera system setups, but in general, you would want to set the camera exposure between 400 ~ 750, microseconds.

IR LEDs

When tracking only active markers, the cameras do not need to emit IR lights. In this case, you can disable the IR settings in the Devices pane.

Active Markers in Motive

Active Labels

Labels in Recorded 3D Data

Unlabeled Markers

In recorded 3D data, the labels of the unlabeled active markers will still indicate that it is an active marker. As shown in the image below, there will be Active prefix assigned in addition to the active ID to indicate that it is an active marker. This applies only to individual active markers that are not auto-labeled. Markers that are auto-labeled using a trackable model will be assigned with a respective label.

Auto-labeled Markers

When a trackable asset (e.g. Rigid Body) is defined using active markers, it's active ID information gets stored in the asset along with marker positions. When auto-labeling the markers in the space, the trackable asset will additionally search for reconstructions with matching active ID, in addition to the marker arrangements, to auto-label a set of markers. This can add additional guard to the auto-labeler and prevents and mis-labeling errors.

Rigid Body Definition

Rigid body definitions created from actively labeled reconstructions will search for respective marker IDs in order to solve the Rigid Body. This gives a huge benefit because the active markers can be placed in perfectly symmetrical marker arrangements among multiple Rigid Bodies and not run into labeling swaps. With active markers, only the 3D reconstructions with active IDs stored under the corresponding Rigid Body definition will contribute to the solve.

Rigid Body Properties

If a Rigid Body was created from actively labeled reconstructions, the corresponding Active ID gets saved under the corresponding Rigid Body properties. In order for the Rigid Body to be tracked, the reconstructions with matching marker IDs in addition to matching marker placements must be tracked in the volume. If the active ID is set to 0, it means no particular marker ID is given to the Rigid Body definition and any reconstructions can contribute to the solve.

Troubleshooting