Overview

Specs

Overview

Specs

Overview

Specs

Overview

Specs

How to Use the User Guide

• Use the Table of Contents to navigate through the guide.

  • In the Desktop view, the Table of Contents appears in the left pane.

This page includes all of the Motive tutorial video for visual learners.

Motive: Installation and Activation

TRC File Format

Captured tracking data can be exported into a Track Row Column (TRC) file, which is a format used in various mocap applications. Exported TRC files can also be accessed from spreadsheet software (e.g. Excel). These files contain raw output data from capture, which include positional data of each labeled and unlabeled marker from a selected Take. Expected marker locations and segment orientation data are not included in the exported files. The header contains basic information such as file name, frame rate, time, number of frames, and corresponding marker labels. Corresponding XYZ data is displayed in the remaining rows of the file.

Overview

Specs

Overview

Specs

Overview

Specs

The API reports "world-space" values for markers and rigid body objects at each frame. It is often desirable to convert the coordinates of points reported by the API from the world-space (or global) coordinates into the local space of the rigid body. This is useful, for example, if you have a rigid body that defines the world space that you want to track markers within.

Rotation values are reported as both quaternions, and as roll, pitch, and yaw angles (in degrees). Quaternions are a four-dimensional rotation representation that provide greater mathematical robustness by avoiding "gimbal" points that may be encountered when using roll, pitch, and yaw (also known as Euler angles). However, quaternions are also more mathematically complex and are more difficult to visualize, which is why many still prefer to use Euler angles.

There are many potential combinations of Euler angles so it is important to understand the order in which rotations are applied, the handedness of the coordinate system, and the axis (positive or negative) that each rotation is applied about.

These are the conventions used in the API for Euler angles:

Before setting up a motion capture system, choose a suitable setup area and prepare it in order to achieve the best tracking performance. This page highlights some of the considerations to make when preparing the setup area for general tracking applications. Note that this page provides just general recommendations and these could vary depending on the size of a system or purpose of the capture.

Indoor Tracking

Overview

Use the Application Settings panel to customize Motive and set default values. This includes camera system setting, data pipeline settings, streaming settings, and hotkeys and shortcuts. Please see the following pages for descriptions of the settings on each tab:

A USB camera system provides high-quality motion capture for small to medium size volumes at an affordable price range. USB camera models include the Flex series (Flex 3 and Flex 13) and Slim 3U models. USB cameras are powered by the OptiHub, which is designed to maximize the capacity of Flex series cameras by providing sufficient power to each camera, allowing tracking at long ranges.

For each USB system, up to four OptiHubs can be used. When incorporating multiple OptiHubs in the system, use RCA synchronization cables to interconnect each hub. A USB system is not suitable for a large volume setup because the USB 2.0 cables used to wire the cameras have a 5-meter length limitation.

If needed, up to two active USB extensions can be used when connecting the OptiHub to the host PC. However, the extensions should not be used between the OptiHub and the cameras. We do not support using more than 2 USB extensions anywhere on a USB 2.0 system running Motive.

Cabling the USB System

Main Components

• Host PC

• USB Cameras

• OptiHub(s) and a power supply for each hub.

• USB 2.0 cables:

OptiHub

The OptiHub is a custom-engineered USB hub that is designed to be incorporated in a USB camera system. It provides both power and external synchronization options. Standard USB ports do not provide enough power for the IR illumination within Flex 13 cameras and they need to be routed through an OptiHub in order to activate the LED array.

USB Load Balancing

When connecting hubs to the computer, load balancing becomes important. Most computers have several USB ports on the front and back, all of which go through two USB controllers. Especially for a large camera count systems (18+ cameras), it is recommended that you evenly split the cameras between the USB controllers to make the best use of the available bandwidth.

OptiSync

OptiSync is a custom synchronization protocol which sends the synchronization signals through the USB cable. It allows each camera to have one USB cable for both data transfer and synchronization instead of having separate USB and daisy-chained RCA synchronization cables as in the older models.

Checkpoint

At this point, all of the connected cameras will be listed on the and the when you start up Motive. Check to make sure all of the connected cameras are properly listed in Motive.

Then, open up the Status Log panel and check there are no 2D frame drops. You may see a few frame drops when booting up the system or when switching between Live and Edit modes; however, this should only occur just momentarily. If the system continues to drop 2D frames, it indicates there is a problem with how the system is delivering the camera data. Please refer to the troubleshooting section for more details.

Camera Highlights

New Camera features, including:

• for all cameras with a single click.

• View camera locations in the pane.

• Set .

• Use .

Continuous Calibration Bumped Camera Settings

As part of the Continuous Calibration settings, the Bumped Camera feature corrects a camera's position in Motive if it is physically bumped in the real 3D space.

See for more information.

Asset Highlights

BaseStations and active pucks are now listed in the . Select a BaseStation to display its properties. Select an Active Tag device to view and change its properties. See for more details.

New tools on the Builder Pane allow you to align the pivot of a rigid body with a geometry offset, a second rigid body, or the location of a camera. Check out the page to learn how.

Other Highlights

Motive 3.1 provides an array of improvements across the board. Additional, a redesigned , and enhancements to the are just a few of the many changes you'll find in this latest release.

BVH File Format

Motive can export tracking data in BioVision Hierarchy (BVH) file format. Exported BVH files do not include individual marker data. Instead, a selected skeleton is exported using hierarchical segment relationships. In a BVH file, the 3D location of a primary skeleton segment (Hips) is exported, and data on subsequent segments are recorded by using joint angles and segment parameters. Only one skeleton is exported for each BVH file, and it contains the fundamental skeleton definition that is required for characterizing the skeleton in other pipelines.

General Export Options

BVH Specific Export Options

Overview

When enabled, the Broadcast Storm Control feature on the NETGEAR ProSafe GSM7228S may interfere with the transmission of data from OptiTrack Ethernet cameras. While this feature is critical to a corporate LAN or other network with internet access, it can cause dropped frames, loss of frame data, camera disconnection, and other issues on a camera system.

For proper system operations, the Storm Control feature must be disabled for all ports used in this aggregator switch. OptiTrack switches ship with these management features disabled.

Temporarily change the IP Address to Access the Uplink Switch

Type Network in the Windows search bar to find and open the Control Panel to View Network Connections. The image below shows the three NICs specified above.

• Double-click or right-click the NIC used to connect to the camera network and select Properties.

• With IPv4 selected, click the Properties button.

• Write down the IP address currently assigned to the Motive PC. You will need to change the address back to this once the switch configuration is updated.

• Change the IP address to 169.254.100.200.

• Enter 255.255.255.0 for the Subnet mask.

• Click OK to save and return to the Properties window.

Configure the Switch

• Open a browser window, enter 169.254.100.100, and press enter.

• This will open the Admin Console for the switch.

• Login to the switch with Username 'admin', and leave Password blank.

• On the Security tab, click the Traffic Control subtab.

• Select Storm Control -> Storm Control Global Configuration from the menu on the left.

• Disable everything in the Port Settings options.

• Click the Maintenance tab and select the Save Config subtab.

• Select Save Configuration from the menu on the left.

• Check the 'Save Configuration' check box. This will update the configuration and retain the new settings the next time the system is restarted.

• Log out of the switch by closing the browser window.

Restore the IP Address

Repeat to access and change the network settings for the NIC used to access the switch. Set the IP address back to the address it was originally.

Tracking Bar Coordinate System

If you wish to change the location and orientation of the global axis, you can use the ground plane tools from the and use a Rigid Body or a calibration square to set the global origin.

Coordinate Systems Tool

When using the Duo/Trio tracking bars, you can set the coordinate origin at the desired location and orientation using either a Rigid Body or a as a reference point. Using a calibration square will allow you to set the origin more accurately. You can also use a custom calibration square to set this.

Adjustig the Coordinate System Steps

1. First set place the calibration square at the desired origin. If you are using a Rigid Body, its position and orientation will be used as the reference.

2. [Motive] Open the .

3. [Motive] Open the Ground Planes page.

Overview

The Link Layer Discovery Protocol (IEEE 802.1AB) advertises the major capabilities and physical descriptions of components on an 802 Local Area Network. This protocol provides network components from different vendors the ability to communicate with each other.

LLDP also controls the Power over Ethernet (PoE) power allocation. In the case of the PrimeX 120 cameras, LLDP prevents the switch from providing sufficient power to the port where the camera is connected. For this reason, the LLDP protocol must be disabled on any port used to connect a PrimeX 120 to the camera network.

Configure Settings

1. From the Motive PC, launch any web browser and type http://169.254.100.100 to open the Management Console for the switch.

2. This will open the login console.

3. Login using the Admin account.

4. If the switch has already been configured, the password is OptiPOE++. Otherwise, leave the password blank.

PoE Port Configuration

Set the values necessary to ensure the PrimeX 120 receives sufficient power once the LLDP settings are turned off.

1. On the System tab, select the PoE settings from the toolbar.

2. Click Advanced in the navigation bar, on the left.

3. Click PoE Port Configuration.

4. Select the port(s) to update.

LLDP Configuration

Update settings to prevent LLDP from interfering with traffic from the PrimeX 120.

1. On the System tab, select the LLDP settings from the toolbar.

2. From the Navigation bar, select LLDP -> Interface Configuration.

3. Disable Transmit, Receive, and Notify for all required ports.

4. Click the Apply button in the upper right corner to commit the changes in the current session.

Disable Storm Control

Storm control security features may throttle traffic from the PrimeX 120 cameras, affecting system performance.

1. On the Security tab, select the Traffic Control settings from the toolbar.

2. From the Navigation bar, select Storm Control -> Storm Control Global Configuration.

3. Disable all Port Settings shown.

4. Click the Apply button in the upper right corner to commit the changes in the current session.

Tracking Bar Coordinate System

If you wish to change the location and orientation of the global axis, you can use the Coordinate Systems Tool which can be found under the Tools tab.

Coordinate Systems Tool

When using the Duo/Trio tracking bars, you can set the coordinate origin at a desired location and orientation using a . Make sure the calibration square is oriented properly.

Adjusting the Coordinate System Steps

1. Place the calibration square at the desired origin.

2. [Motive] Open the Coordinate System Tools pane under the Tools tab.

3. [Motive] Select the Calibration square markers from the

This page provides information on the Probe pane, which can be accessed under the Tools tab or by clicking on the icon from the toolbar.

Overview

This section highlights what's in the Probe pane. For detailed instructions on how to use the Probe pane to collect measurement samples, read through Measurement Probe Kit Guide.

Probe Calibration

The Probe Calibration feature under the Rigid Body edit options can be used to re-calibrate a pivot point of a measurement probe or a custom Rigid Body. This step is also completed as one of the calibration steps when first creating a measurement probe, but you can re-calibrate it under the Modify tab.

Steps

1. In Motive, select the Rigid Body or a measurement probe.

2. Bring out the probe into the tracking volume where all of its markers are well-tracked.

3. Place and fit the tip of the probe in one of the slots on the provided calibration block.

4. Click Start

Digitized Points

The Digitized Points section is used for collecting sample coordinates using the probe. You can select which Rigid Body to use from the drop-down menu and set the number of frames used to collect the sample. Clicking on the Sample button will trigger Motive to collect a sample point and save it into the C:\Users\[Current User]\Documents\OptiTrack\measurements.csv file.

When needed, export the measurements of the accumulated digitized points into a separate CSV file, and/or clear the existing samples to start a new set of measurements

Live Position

Shows the live X/Y/Z position of the calibrated probe tip.

Last Point

Shows the live X/Y/Z position of the last sampled point.

Live Distance

Shows the distance between the last point and the live position of the probe tip.

Distance

Shows the distance between the last two collected samples.

Angle

Shows the angle between the last three collected samples

The Assets pane in Motive lists out all of the assets involved in the Live, or recorded, capture and allows users to manage them. This pane can be accessed under the View tab in Motive or by clicking icon on the main toolbar.

Overview

Assets (Current Take)

A list of all assets associated with the take is displayed in the Assets pane. Here, view the assets and you can right click on an asset to export, remove, or rename selected asset from the current take.

You can also enable or disable assets by checking or unchecking, the box next to each asset. Only enabled assets will be visible in the 3D viewport and used by the to label the markers associated with respective assets.

Context Menu Options

In the Assets pane, the context menu for involved assets can be accessed by clicking on the or by right-clicking on a selected Take(s). The context menu lists out available actions for the corresponding assets.

All Assets

Export Asset

Exports selected Rigid Bodies into either a Motive file (.motive) or CSV. Exports selected Skeletons into either Motive file (.motive) or an FBX file.

Export Constraints

Exports Skeleton marker template constraint XML file. The exported constraints files contain marker can be modified and imported again.

Import Constraints

Imports Skeleton marker template constraint XML file onto the selected asset. If you wish to apply the imported XML for labeling, all of the Skeleton markers need to be unlabeled and auto-labeled again.

Generate Constraints

Imports the default Skeleton marker template constraint XML files. This basically colors the labeled markers and creates marker sticks that inter-connects between each of consecutive labels.

Solve

This is only possible when post-processing a recorded TAK. Solving an Asset bakes its 6 DoF data into the recording. Once the asset is solved, Motive plays back the recording from the recorded Solved data.

For Skeleton Assets

Recalibrate From Markers

Re-calibrates an existing Skeleton. This feature is essentially same as re-creating a Skeleton using the same Skeleton Marker Set. See page for more information on using the Skeleton template XML files.

Operating Range

• 0 to 50 degrees Celsius

• 20% to 80% relative humidity (non-condensing)

Software Installation

1. Download the Motive 3.1 software installer from the to each host PC.

2. Run the installer and follow its prompts.

Connect the Hardware

Please see the section of the page for computer specifications.

Components Provided in the Box

• Duo 3 or Trio 3 device

• I/O-X (breakout box)

• Power adapter and cord

• Camera bar cable (attached to I/O-X)

Steps

1. Mount the camera bar in the designated location.

2. Connect the Camera Bar Cable to the back of the camera and to the I/O-X device, as shown in the diagram above.

3. Connect the I/O-X device to the PC using the USB uplink cable.

4. Connect the power cable to the I/O-X device and plug it into a power source.

Sync Out

The Duo 3 or Trio 3 cameras use a preset frequency for timing and can run at 25 Hz, 50 Hz or 100 Hz. To synchronize other devices with the Duo or Trio, use a BNC cable to connect an input port on the receiving device to the Sync Out port on the I/O-X device.

Output Options

Output options are set in the Properties pane. Select T-Bar Sync in the Devices pane to change output options:

• Exposure Time: Sends a high signal based on when the camera exposes.

• Passthrough: Sync In signal is passed through to the output port.

• Recording Gate: Low electrical signal (0V) when not recording and a high (3.3V) signal when recording is in progress.

• Gated Exposure Time: ends a high signal based on when the camera exposes, only while recording is in progress.

Sync In

Timing signals from other devices can be attached to the Duo 3 or Trio 3 using the I/O-X device's Sync In port and a BNC cable. However, this port does not allow you to change the rate of the device reliably. The only functionality that may work is passing the data through to the output port.

Run Motive

• The Duo 3 and Trio 3 ship with a free license for Motive:Tracker installed.

• The camera is pre-calibrated and no wanding is required. The user can .

• The Duo 3 and Trio 3 run in Precision, Grayscale, and MJPEG modes. Object mode is not available.

Status LEDs

LED lights on the back of the Duo 3 or Trio 3 indicate the device's status.

Left LED Lights

Right LED Lights

Overview

When using streamed Rigid Body data to animate a real-life replicated 3D model, it's critical that the Rigid Body's pivot point aligns with the location of the pivot point in the corresponding 3D model. If they are not aligned, the animated motion will not be in a 1:1 ratio to the actual motion.

This alignment is critical for real-time VR applications where real-life objects are 3D modeled and animated in the scene.

Live and Edit Modes

These steps can be completed in Live or Edit mode.

There are two modes for editing:

• Edit: Playback in standard Edit mode displays and streams the processed 3D data saved in the recorded Take. Changes made to settings and assets are not reflected in the Viewport until the Take is .

• Edit 2D: Playback in Edit 2D mode performs a live reconstruction of the 3D data, immediately reflecting changes made to settings or assets. These changes are displayed in real-time but are not saved into the recording until the Take is and saved. To playback in 2D mode, click the Edit button and select Edit 2D.

Aligning Rigid Body Pivot Point

There are two methods to align the pivot point of a rigid body. We recommend using the measurement probe method as it is the most accurate.

Measurement Probe

Step 1. Create a Rigid Body of the target object

from the markers on the target object. By default, Motive will position the pivot point of the Rigid Body at the geometric center of the marker placements. Once the Rigid Body has been created, place the object in a stable location where it will remain stationary.

Step 2. Create a measurement probe asset

Please refer to page for instructions to create a measurement probe asset in Motive.

You can purchase an OptiTrack probe or create your own.

Step 3. Collect data points to outline the silhouette

Use the created measurement probe to collect that outline the silhouette of the object. Mark all corners and other key features on the object.

Step 4. Attach 3D model

After generating 3D data points using the probe, attach the game geometry (obj file) to the Rigid Body.

1. Select the Rigid Body in either the Devices pane or the 3D Viewport to show its properties in the Properties pane.

2. In the Visuals section, select Custom Model under the Geometry property. (Note: this is an Advanced setting.)

3. This will open the Attached Geometry field. Click the folder to the right of the field to browse to the location of your 3D model.

Step 5. Translate the pivot point

Next, use the to translate the 3D model to align with the silhouette sample collected in Step 3. Move, rotate, and scale the model until it is perfectly aligned with the silhouette.

Step 6. Align to Geometry

1. With both the Rigid Body and the 3D model selected, open the Modify tab in the Builder pane.

2. In the Align to... section, select Geometry.

3. The pivot point for the Rigid Body will snap to align with the pivot point for the 3D model.

Reference Grayscale View

Use a reference camera when the option to use the probe method is not available.

1. Change the Video Type for one of the cameras to grayscale mode.

2. Right-click the camera and select Make Reference.

3. This will create a Rigid Body overlay in the . Follow steps , , and above using the reference video to align the Rigid Body pivot.

In optical motion capture systems, proper camera placement is very important in order to efficiently utilize the captured images from each camera. Before setting up the cameras, it is good idea to plan ahead and create a blueprint of the camera placement layout. This page highlights the key aspects and tips for efficient camera placements.

A well-arranged camera placement can significantly improve the tracking quality. When tracking markers, 3D coordinates are reconstructed from the 2D views seen by each camera in the system. More specifically, correlated 2D marker positions are triangulated to compute the 3D position of each marker. Thus, having multiple distinct vantages on the target volume is beneficial because it allows wider angles for the triangulation algorithm, which in turn improves the tracking quality. Accordingly, an efficient camera arrangement should have cameras distributed appropriately around the capture volume. By doing so, not only the tracking accuracy will be improved, but uncorrelated rays and marker occlusions will also be prevented. Depending on the type of tracking application, capture volume environment, and the size of a mocap system, proper camera placement layouts may vary.

Planning Camera Placement

An ideal camera placement varies depending on the capture application. In order to figure out the best placements for a specific application, a clear understanding of the fundamentals of optical motion capture is necessary.

To calculate 3D marker locations, tracked markers must be simultaneously captured by at least two synchronized cameras in the system. When not enough cameras are capturing the 2D positions, the 3D marker will not be present in the captured data. As a result, the collected marker trajectory will have gaps, and the accuracy of the capture will be reduced. Furthermore, extra effort and time will be required for the data. Thus, marker visibility throughout the capture is very important for tracking quality, and cameras need to be capturing at diverse vantages so that marker occlusions are minimized.

Depending on captured motion types and volume settings, the instructions for ideal camera arrangement vary. For applications that require tracking markers at low heights, it would be beneficial to have some cameras placed and aimed at low elevations. For applications tracking markers placed strictly on the front of the subject, cameras on the rear won't see those and as a result, become unnecessary. For large volume setups, installing cameras circumnavigating the volume at the highest elevation will maximize camera coverage and the capture volume size. For captures valuing extreme accuracy, it is better to place cameras close to the object so that cameras capture more pixels per marker and more accurately track small changes in their position.

General Guide

For common applications of tracking 3D position and orientation of Skeletons and Rigid Bodies, place the cameras on the periphery of the capture volume. This setup typically maximizes the camera overlap and minimizes wasted camera coverage. General tips include the following:

• Mount cameras at the desired maximum height of the capture volume.

• Distribute the cameras equidistantly around the setup area.

• Adjust angles of cameras and aim them towards the target volume.

• For cameras with rectangular FOVs, mount the cameras in landscape orientation. In very small setup areas, cameras can be aimed in portrait orientation to increase vertical coverage, but this typically reduces camera overlap, which can reduce marker continuity and data quality.

Camera Placement Checkpoints

Around the volume

For common applications tracking a Skeleton or a Rigid Body to obtain the 6 Degrees of Freedom (x,y,z-position and orientation) data, it is beneficial to arrange the cameras around the periphery of the capture volume for tracking markers both in front and back of the subject.

Camera Elevations

For typical motion capture setup, placing cameras at high elevations is recommended. Doing so maximizes the capture coverage in the volume, and also minimizes the chance of subjects bumping into the truss structure which can degrade calibration. Furthermore, when cameras are placed at low elevations and aimed across from one another, the synchronized IR illuminations from each camera will be detected, and will need to be from the 2D view.

However, it can be beneficial to place cameras at varying elevations. Doing so will provide more diverse viewing angles from both high and low elevations and can significantly increase the coverage of the volume. The frequency of marker occlusions will be reduced, and the accuracy of detecting the marker elevations will be improved.

Camera to Camera Distance

Separating every camera by a consistent distance is recommended. When cameras are placed in close vicinity, they capture similar images on the tracked subject, and the extra image will not contribute to preventing occlusions or the reconstruction calculations. This overlap detracts from the benefit of a higher camera count and also doubles the computational load for the calibration process. Moreover, this also increases the chance of marker occlusions because markers will be blocked from multiple views simultaneously whenever obstacles are introduced.

Camera to Object Distance

An ideal distance between a camera and the captured subject also depends on the purpose of the capture. A long distance between the camera and the object gives more camera coverage for larger volume setups. On the other hand, capturing at a short distance will have less camera coverage but the tracking measurements will be more accurate. The cameras lens focus ring may need to be adjusted for close-up tracking applications.

Placement Examples

OptiTrack motion capture systems can use both passive and active markers as indicators for 3D position and orientation. An appropriate marker setup is essential for both tracking the quality and reliability of captured data. All markers must be properly placed and must remain securely attached to surfaces throughout the capture. If any markers are taken off or moved, they will become unlabeled from the Marker Set and will stop contributing to the tracking of the attached object. In addition to marker placements, marker counts and specifications (sizes, circularity, and reflectivity) also influence the tracking quality. Passive (retroreflective) markers need to have well-maintained retroreflective surfaces in order to fully reflect the IR light back to the camera. Active (LED) markers must be properly configured and synchronized with the system.

Retroreflective Markers

OptiTrack cameras track any surfaces covered with retroreflective material, which is designed to reflect incoming light back to its source. IR light emitted from the camera is reflected by passive markers and detected by the camera’s sensor. Then, the captured reflections are used to calculate the 2D marker position, which is used by Motive to compute 3D position through reconstruction. Depending on which markers are used (size, shape, etc.) you may want to adjust the camera filter parameters from the Live Pipeline settings in .

Marker Size

The size of markers affects visibility. Larger markers stand out in the camera view and can be tracked at longer distances, but they are less suitable for tracking fine movements or small objects. In contrast, smaller markers are beneficial for precise tracking (e.g. facial tracking and microvolume tracking), but have difficulty being tracked at long distances or in restricted settings and are more likely to be occluded during capture. Choose appropriate marker sizes to optimize the tracking for different applications.

Circularity

If you wish to track non-spherical retroreflective surfaces, lower the Circularity value in in the application settings. This adjusts the circle filter threshold and non-circular reflections can also be considered as markers. However, keep in mind that this will lower the filtering threshold for extraneous reflections as well. If you wish to track non-spherical retroreflective surfaces, lower the Circularity value from the in the application settings.

Worn markers

All markers need to have a well-maintained retroreflective surface. Every marker must satisfy the brightness Threshold defined from the to be recognized in Motive. Worn markers with damaged retroreflective surfaces will appear to a dimmer image in the camera view, and the tracking may be limited.

Custom Markers

OptiTrack cameras can track any surface covered with retro-reflective material. For best results, markers should be completely spherical with a smooth and clean surface. Hemispherical or flat markers (e.g. retro-reflective tape on a flat surface) can be tracked effectively from straight on, but when viewed from an angle, they will produce a less accurate centroid calculation. Hence, non-spherical markers will have a less trackable range of motion when compared to tracking fully spherical markers.

Active Markers

OptiTrack Active Markers

OptiTrack's active solution provides advanced tracking of IR LED markers to accomplish the best tracking results. This allows each marker to be labeled individually. Please refer to the page for more information.

Custom Active Markers

Active (LED) markers can also be tracked with OptiTrack cameras when properly configured. We recommend using OptiTrack’s Ultra Wide Angle 850nm LEDs for active LED tracking applications. If third-party LEDs are used, their illumination wavelength should be at 850nm for best results. Otherwise, light from the LED will be filtered by the band-pass filter.

If your application requires tracking LEDs outside of the 850nm wavelength, the OptiTrack camera should not be equipped with the 850nm band-pass filter, as it will cut off any illumination above or below the 850nm wavelength. An alternative solution is to use the 700nm short-pass filter (for passing illumination in the visible spectrum) and the 800nm long-pass filter (for passing illumination in the IR spectrum). If the camera is not equipped with the filter, the Filter Switcher add-on is available for purchase at our . There are also other important considerations when incorporating active markers in Motive:

• Place a spherical diffuser around each LED marker to increase the illumination angle. This will improve the tracking since bare LED bulbs have limited illumination angles due to their narrow beamwidth. Even with wide-angle LEDs, the lighting coverage of bare LED bulbs will be insufficient for the cameras to track the markers at an angle.

• If an LED-based marker system will be strobed (to increase range, offset groups of LEDs, etc.), it is important to synchronize their strobes with the camera system. If you require a LED synchronization solution, please contact one of our to learn more about OptiTrack’s RF-based LED synchronizer.

• Many applications that require active LEDs for tracking (e.g. very large setups with long distances from a camera to a marker) will also require active LEDs during calibration to ensure sufficient overlap in-camera samples during the wanding process. We recommend using OptiTrack’s Wireless Active LED Calibration Wand for best results in these types of applications. Please contact one of our Sales Engineers to order this calibration accessory.

Marker Placement

Proper marker placement is vital for quality of motion capture data because each marker on a tracked subject is used as indicators for both position and orientation. When an asset (a Rigid Body or Skeleton) is created in Motive, its unique spatial relationships of the markers are calibrated and recorded. Then, the recorded information is used to recognize the markers in the corresponding asset during the process. For best tracking results, when multiple subjects with a similar shape are involved in the capture, it is necessary to offset their marker placements to introduce the asymmetry and avoid the congruency.

Read more about marker placements from the page and the page.

Marker Bases and Adhesives

Prepare the markers and attach them on the subject, a Rigid Body or a person. Minimize extraneous reflections by covering shiny surfaces with non-reflective tapes. Then, securely attach the markers to the subject using enough adhesives suitable for the surface. There are various types of adhesives and marker bases available on our for attaching the marker: Acrylic, Rubber, Skin adhesive, and Velcro. Multiple types of marker bases are also available: carbon fiber filled bases, Velcro bases, and snap-on plastic bases.

This page provides information and instructions on how to utilize the Probe Measurement Kit.

Overview

Measurement probe tool utilizes the precise tracking of OptiTrack mocap systems and allows you to measure 3D locations within a capture volume. A probe with an attached Rigid Body is included with the purchased measurement kit. By looking at the markers on the Rigid Body, Motive calculates a precise x-y-z location of the probe tip, and it allows you to collect 3D samples in real-time with sub-millimeter accuracy. For the most precise calculation, a probe calibration process is required. Once the probe is calibrated, it can be used to sample single points or multiple samples to compute distance or the angle between sampled 3D coordinates.

Measurement kit includes:

• Measurement probe

• Calibration block with 4 slots, with approximately 100 mm spacing between each point.

Using the Probe

This section provides detailed steps on how to create and use the measurement probe. Please make sure the camera volume has been successfully before creating the probe. System calibration is important on the accuracy of marker tracking, and it will directly affect the probe measurements.

Step 1: Probe Calibration

Creating a probe using the Builder pane

1. Open the under and click Rigid Bodies.

2. Bring the probe out into the tracking volume and create a from the markers.

3. Under the Type drop-down menu, select Probe. This will bring up the options for defining a Rigid Body for the measurement probe.

Step 2: Sample Collection

Using the Probe pane for sample collection

1. Under the Tools tab, open the .

2. Place the probe tip on the point that you wish to collect.

3. Click Take Sample on the Measurement pane.

4. A Virtual Reference point is constructed at the location and the coordinates of the point are displayed in the

Export Samples

As the samples are collected, their coordinate data will be written out into the CSV files automatically into the OptiTrack documents folder which is located in the following directory: C:\Users\[Current User]\Documents\OptiTrack. 3D positions for all of the collected measurements and their respective RMSE error values along with distances between each consecutive sample point will be saved in this file.

Also, If needed, you can trigger Motive to export the collected sample coordinate data into a designated directory. To do this, simply click on the export option on the Probe pane.

Real-time Streaming

The location of the probe tip can also be streamed into another application in real-time. You can do this by the probe Rigid Body position via . Once calibrated, the pivot point of the Rigid Body gets positioned precisely at the tip of the probe. The location of a pivot point is represented by the corresponding Rigid Body x-y-z position, and it can be referenced to find out where the probe tip is located.

In Motive, the Application Settings can be accessed under the View tab or by clicking icon on the main toolbar. Default Application Settings can be recovered by Reset Application Settings under the Edit Tools tab from the main Toolbar.

If you have an audio input device, you can record synchronized audio along with motion capture data in Motive. Recorded audio files can be played back from a captured Take or be exported into a WAV audio files. This page details how to record and playback audio in Motive. Before using an audio input device (microphone) in Motive, first make sure that the device is properly connected and configured in Windows.

Audio Recording/Playback

Audio Settings

In Motive, audio recording and playback settings can be accessed from .

Audio Recording Steps

1. In Motive, open the Audio Settings, and check the box next to Enable Capture.

2. Select the audio input device that you want to use.

3. Press the Test button to confirm that the input device is properly working.

4. Make sure the device format of the recording device matches the device format that will be used in the playback devices (speakers and headsets).

Audio Playback Steps

1. Enable the Audio device before loading the TAK file with audio recordings. Enabling after is currently not supported, as the audio engine gets initialized on TAK load

2. Open a Take that includes audio recordings.

3. To playback recorded audio from a Take, check the box next to Enable Playback.

Device Format

In order to playback audio recordings in Motive, audio format of recorded sounds MUST match closely with the audio format used in the output device. Specifically, communication channels and frequency of the audio must match. Otherwise, recorded sound will not be played back.

The recorded audio format is determined by the format of a recording device that was used when capturing Takes. However, audio formats in the input and output devices may not always agree. In this case, you will need to adjust the input device properties to match them. Device's audio format can be configured under the Sound settings in Windows. In Sound settings (accessed from Control Panel), select the recording device, click on Properties, and the default format can be changed under the Advanced Tab, as shown in the image below.

Audio Export

Recorded audio files can be exported into WAV format. To export, right-click on a Take from the and select Export Audio option in the context menu.

Other Options

If you want to use an external audio input system to record synchronized audio, you will need to connect the motion capture system into a Genlock signal or a Timecode device. This will allow you to precisely synchronize the recorded audio along with the capture data.

For more information on synchronizing external devices, read through the page.

PrimeX 41, PrimeX 22, Prime 41*, and Prime 17W* camera models have powerful tracking capability that allows tracking outdoors. With strong infrared (IR) LED illuminations and some adjustments to its settings, a Prime system can overcome sunlight interference and perform 3D capture. This page provides general hardware and software system setup recommendations for outdoor captures.

Please note that when capturing outdoors, the cameras will have shorter tracking ranges compared to when tracking indoors. Also, the system calibration will be more susceptible to change in outdoor applications because there are environmental variables (e.g. sunlight, wind, etc.) that could alter the system setup. To ensure tracking accuracy, routinely re-calibrate the cameras throughout the capture session.

Weather and Backgrounds

Even though it is possible to capture under the influence of the sun, it is best to pick cloudy days for captures in order to obtain the best tracking results. The reasons include the following:

• Bright illumination from the daylight will introduce extraneous reconstructions, requiring additional effort in the post-processing on cleaning up the captured data.

• Throughout the day, the position of the sun will continuously change as will the reflections and shadows of the nearby objects. For this reason, the camera system needs to be routinely re-masked or re-calibrated.

The surroundings can also work to your advantage or disadvantage depending on the situation. Different outdoor objects reflect 850 nm Infrared (IR) light in different ways that can be unpredictable without testing. Lining your background with objects that are black in Infrared (IR) will help distinguish your markers from the background better which will help with tracking. Some examples of outdoor objects and their relative brightness is as follows:

• Grass typically appears as bright white in IR.

• Asphalt typically appears dark black in IR.

• Concrete depends, but it's usually a gray in IR.

Hardware Setup Recommendations

1. [Camera Setup]

In general, setting up a truss system for mounting the cameras is recommended for stability, but for outdoor captures, it could be too much effort to do so. For this reason, most outdoor capture applications use tripods for mounting the cameras.

2. [Camera Setup]

Do not aim the cameras directly towards the sun. If possible, place and aim the cameras so that they are capturing the target volume at a downward angle from above.

3. [Camera Setup]

Increase the f-stop setting in the Prime cameras to decrease the aperture size of the lenses. The f-stop setting determines the amount of light that is let through the lenses, and increasing the f-stop value will decrease the overall brightness of the captured image allowing the system to better accommodate for sunlight interference. Furthermore, changing this allows camera exposures to be set to a higher value, which will be discussed in the later section. Note that f-stop can be adjusted only in PrimeX 41, PrimeX 22, Prime 41*, and Prime 17W* camera models.

4. [Camera Setup] Utilize shadows

Even though it is possible to capture under sunlight, the best tracking result is achieved when the capture environment is best optimized for tracking. Whenever applicable, utilize shaded areas in order to minimize the interference by sunlight.

Motive Settings

1. [Camera Settings]

Increase the LED setting on the camera system to its maximum so that IR LED illuminates at its maximum strength. Strong IR illumination will allow the cameras to better differentiate the emitted IR reflections from ambient sunlight.

2. [Camera Settings]

In general, increasing camera exposure makes the overall image brighter, but it also allows the IR LEDs to light up and remain at its maximum brightness for a longer period of time on each frame. This way, the IR illumination is stronger on the cameras, and the imager can more easily detect the marker reflections in the IR spectrum.

When used in combination with the increased f-stop on the lens, this adjustment will give a better distinction of IR reflections. Note that this setup applies only for outdoor applications, for indoor applications, the exposure setting is generally used to control overall brightness of the image.

*Legacy camera models

\

Overview

This page provides instructions on how to configure the CameraNicFilter.xml file to whitelist or blacklist specific cameras from the connected camera network.

Starting with Motive 2.1, you can specify which cameras to utilize among the connected Ethernet cameras in a system. This can be done by setting up an XML file (CameraNicFilter.xml) and placing it in Motive's ProgramData directory: C:\ProgramData\OptiTrack\Motive\CameraNicFilter.xml. Once this is set, Motive will initialize only the specified cameras within the respective network interface. This allows users to distribute the cameras to specific network interfaces on a computer or on multiple computers.

Please see our and pages for detailed setup instructions for an Ethernet camera system.

Ethernet Camera System

An Ethernet camera system uses Ethernet switches and cables to connect to the Motive PC. Ethernet-based camera models include PrimeX series (PrimeX 13, 13W, 22, 41, 120), SlimX series (SlimX 13, 120), and Prime Color models.

Ethernet cables not only offer faster data transfer rates, but they also provide power over Ethernet to each camera while transferring the data to the host PC. This reduces the number of cables required and simplifies the overall setup. With a maximum length of 100m, Ethernet cables allow coverage over large volumes.

Overview

In Motive, an Asset is a set of markers that define a specific object to be tracked in the capture. Asset tracking data can be sent to other pipelines (e.g., animations and biomechanics) for extended applications.

When an asset is created, Motive automatically applies a set of predefined labels to the reconstructed trajectories (markers) using Motive's tracking and labeling algorithms. Motive calculates the position and orientation of the asset using the labeled markers.

There are three types of assets, covering a full range of tracking needs:

This page provides instructions on how to utilize the Gizmo tool for modifying asset definitions (Rigid Bodies and Skeletons) on the of Motive

General Windows Setup

Debloat Windows

You'll want to remove as much bloatware from your PC in order to optimize your system and make sure minimal unnecessary background processes are running. Background process can take up valuable CPU resources from Motive and cause frame drops while running your camera system.

Overview

The Assets tab in the application settings panel is where you can configure the creation properties for Rigid Body and Skeleton assets. In other words, all of the settings configured in this tab will be assigned to the Rigid Body and Skeleton that are newly created in Motive.

During process, a calibration square is used to define global coordinate axes as well as the ground plane for the capture volume. Each calibration square has different vertical offset value. When defining the ground plane, Motive will recognize the square and ask user whether to change the value to the matching offset.

In Motive, the Edit Tools pane can be accessed under the or by clicking icon on the main toolbar.

The Edit Tools pane contains the functionality to modify 3D data. Four main functions exist: trimming trials, filling gaps, smoothing trajectories and swapping data points. Trimming trials refers to the clearing of data points before and after a gap. Filling gaps is the process of filling in a markers trajectory for each frame that has no data. Smoothing trajectories filters out unwanted noise in the signal. Swapping allows two markers to swap their trajectories.

Read through the page to learn about utilizing the edit tools.

Tails

In order to ensure that every camera in a mocap system takes full advantage of its capability, they need to be focused and aimed at the target tracking volume. This page includes detailed instructions on how to adjust the focus and aim of each camera for an optimal motion capture. OptiTrack cameras are focused at infinity by default, which is generally sufficient for common tracking applications. However, we recommend users always double-check the camera view and make sure the captured images are focused when first setting up the system. Obtaining best quality image is very important as 3D data is derived from the captured images.

General Steps

This page provides detailed information on the continuous calibration feature, which can be enabled from the Calibration pane. For additional Continuous Calibration features, please see the Continuous Calibration (Info Pane) page.

Overview

The Continuous Calibration feature ensures your system always remains optimally calibrated, requiring no user intervention to maintain the tracking quality. It uses highly sophisticated algorithms to evaluate the quality of the calibration and the triangulated marker positions. Whenever the tracking accuracy degrades, Motive will automatically detect and update the calibration to provide the most globally optimized tracking system.

Key Features

• Ease of use. This feature provides much easier user experience because the capture volume will not have to be re-calibrated as often, which will save a lot of time. You can simply enable this feature and have Motive maintain the calibration quality.

• Optimal tracking quality. Always maintains the best tracking solution for live camera systems. This ensures that your captured sessions retain the highest quality calibration. If the system receives inadequate information from the environment, the calibration with not update and your system never degrades based on sporadic or spurious data. A moderate increase in the number of real optical tracking markers in the volume and an increase in camera overlap improves the likelihood of a higher quality update.

• Works with all camera types. Continuous calibration works with all OptiTrack camera models.

Requirements

For continuous calibration to work as expected, the following criteria must be met:

• Live Mode Only. Continuous calibration only works in .

• Markers Must Be Tracked. Continuous calibration looks at tracked reconstructions to assess and update the calibration. Therefore, at least some number of markers must be tracked within the volume.

• Majority of Cameras Must See Markers. A majority of cameras in a volume needs to receive some tracking data within a portion of their field of view in order to initiate the calibration process. Because of this, traditional perimeter camera systems typically work the best. Each camera should additionally see at least 4 markers for optimal calibration. If not all the cameras see the markers at the same time, anchor markers will need to be set up to improve the calibration updates.

How to Use

To enable Continuous Calibration, calibrate the camera system first and enable the Continuous Calibration setting at the bottom of the . Once enabled, Motive continuously monitors the residual values in captured marker reconstructions, and when the updated calibration is better than the existing one, it will get updated automatically. Please note that at least four (default) marker samples must be being tracked in the volume for the continuous calibration to work. You will also be able to monitor the sampling progress and when the calibration has been last updated.

Anchor Markers

Anchor markers further improve the continuous calibration. When properly configured, anchor markers establish a known point-of-reference for continuous calibration updates, especially on systems that consists of multiple sets of cameras that are separated into different tracking areas, by obstructions or walls, without camera view overlap. Anchor markers provide extra assurance that the global origin will not shift during each update, which the continuous calibration feature checks for as well.

Active Anchor Markers

Active markers are best to use for anchors due to their unique active IDs, which improve accuracy, remove ambiguity, and enhance continuous calibration all around.

• Cameras will always correctly identify an active marker even when no other markers are visible or after an occlusion. This helps the system calibrate more frequently, and to quickly adjust after more significant disturbances.

• Anchor markers are critical to maintaining a single calibration throughout a partitioned volume. Active markers ensure that the cameras can correctly identify each anchor marker location.

• Active markers allow bumped cameras to update faster and more accurately, and to recover from larger disturbances than passive markers.

Anchor Marker Setup

Follow the steps below for setting up the anchor marker in Motive:

Adding Anchor Markers in Motive

1. First, make sure the entire camera volume is fully and prepared for marker tracking.

2. Place any number of markers in the volume to assign them as the anchor markers.

3. Make sure these markers are securely fixed in place within the volume. It's important that the distances between these markers do not change throughout the continuous calibration updates.

Camera Partitions

For multi-room setups, it is useful to group cameras into partitions. This allows for Continuous Calibration to run in each individual room without the need for camera view overlap.

Properties Pane: Camera

From the Properties pane of a camera you can assign a Partition ID from the advanced settings.

You'll want to assign all the cameras in the same room the same Partition ID. Once assigned these cameras will all contribute to Continuous Calibration for their particular space. This will help ensure the accuracy of Continuous Calibration for each individual space that is a part of the whole system.

Editing Camera Positions with Gizmo Tool

In the event that you need to manually adjust cameras in the 3D view, you can enable Editable in 3D View in . To access this setting, you'll need to select Show Advanced from the 3-dot more options dropdown at the top. This will populate a Calibration section on this window.

This allows you to use the to Translate, Rotate, and Scale cameras to their desired locations.

In Motive, the Application Settings can be accessed under the View tab or by clicking icon on the main toolbar. Default Application Settings can be recovered by Reset Application Settings under the Edit Tools tab from the main Toolbar.

Mouse

Customizing Mouse Actions

The Mouse tab under the application settings is where you can check and customize the mouse actions to navigate and control in Motive.

Basic Controls

The following table shows the most basic mouse actions:

Preset Profile

You can also pick a preset mouse action profiles to use. The presets can be accessed from the below drop-down menu. You can choose from the provided presets, or save out your current configuration into a new profile to use it later.

Keyboard

Customizing Hotkeys

The Keyboard tab under the application settings allows you to assign specific hotkey actions to make Motive easier to use. List of default key actions can be found in the following page also:

Hotkey Profiles

Configured hotkeys can be saved into preset profiles to be used on a different computer or to be imported later when needed. Hotkey presets can be imported or loaded from the drop-down menu:

Choosing an appropriate camera mounting solution is very important when setting up a capture volume. A stable setup not only prevents camera damage from unexpected collisions, but it also maintains calibration quality throughout capture. All OptiTrack cameras have ¼-20 UNC Threaded holes – ¼ inch diameter, 20 threads/inch – which is the industry standard for mounting cameras. Before planning the mount structures, make sure that you have optimized your plans.

This page covers different video modes that are available on the OptiTrack cameras. Depending on the video mode that a camera is configured to, captured frames are processed differently, and only the configured video mode will be recorded and saved in Take files.

Video Types

Video types, or image-processing modes, available in OptiTrack Cameras

There are different video types, or image-processing modes, which could be used when capturing with OptiTrack cameras. Dending on the camera model, the available modes vary slightly. Each video mode processes captured frames differently at both camera hardware and software level. Furthermore, precision of the capture and required amount of CPU resources will vary depending on the configured video type.

C3D Export

Tracking data can be exported into the C3D file format. C3D (Coordinate 3D) is a binary file format that is widely used especially in biomechanics and motion study applications. Recorded data from external devices, such as force plates and NI-DAQ devices, will be recorded within exported C3D files. Note that common biomechanics applications use a Z-up right-hand coordinate system, whereas Motive uses a Y-up right-hand coordinate system. More details on coordinate systems are described in the later section. Find more about C3D files from .

The Labels pane is used to assign, remove, and edit marker labels in the and is used along with the for complete post-processing. For a detailed explanation of the labeling workflow, read the page.

Open the Labels pane from the View menu or by clicking the button on the main toolbar.

Overview

In Motive, the Application Settings can be accessed under the or by clicking icon on the main toolbar. Default Application Settings can be recovered by Reset Application Settings under the Edit Tools tab from the main .

In Motive, the Data Streaming pane can be accessed under the or by clicking icon on the main toolbar. For explanations on the streaming workflow, read through the page.

NatNet Basic Settings

This section allows you to stream tracking data via Motive's free streaming plugins or any custom-built NatNet interfaces. To begin streaming, select Broadcast Frame Data

Overview

This page includes detailed step-by-step instructions on customizing constraint XML files for assets. In order to customize the marker labels, marker colors, marker sticks, and weights for an asset, a constraint XML file may be exported, customized, and loaded back into Motive. Alternately, the can be used to modify the marker names, color, and weight and the can be used to customize marker sticks directly in Motive. This process has been standardized between asset types with the only exception being that marker sticks for Rigid Bodies does not work in Motive 3.0.