Quick Start Guide: Getting Started
Welcome to the Quick Start Guide: Getting Started!
This guide provides a quick walk-through of installing and using OptiTrack motion capture systems. Key concepts and instructions are summarized in each section of this page to help you get familiarized with the system and get you started with the capture experience.
Note that Motive offers features far beyond the ones listed in this guide, and the capability of the system can be further optimized to fit your specific capture applications using the additional features. For more detailed information on each workflow, read through the corresponding workflow pages in this wiki: hardware setup and software setup.
For best tracking results, you need to prepare and clean up the capture environment before setting up the system. First, remove unnecessary objects that could block the camera views. Cover open windows and minimize incoming sunlight. Avoid setting up a system over reflective flooring since IR lights from cameras may get reflected and add noise to the data. If this is not an option, use rubber mats to cover the reflective area. Likewise, items with reflective surfaces or illuminating features should be removed or covered with non-reflective materials in order to avoid extraneous reflections.
Key Checkpoints for a Good Capture Area
- Minimize ambient lights, especially sunlight and other infrared light sources.
- Clean capture volume. Remove unnecessary obstacles within the area.
- Tape, or Cover, remaining reflective objects in the area.
Ethernet Camera Models: PrimeX series and SlimX 13 cameras. Follow the below wiring diagram and connect each of the required system components.
Single PoE Switch
Multiple Poe Switch (High camera counts)
Switch Power Budget and Camera Power Requirements
Click image to enlarge.
- Connect PoE Switch(s) into the Host PC: Start by connecting a PoE switch into the host PC via an Ethernet cable. Since the camera system takes up a large amount of data bandwidth, the Ethernet camera network traffic must be separated from the office/local area network. If the computer used for capture is connected to an existing network, you will need to use a second Ethernet port or add-on network card for connecting the computer to the camera network. When you do, make sure to turn off your computer's firewall for the particular network under Windows Firewall settings.
- Connect the Ethernet Cameras to the PoE Switch(s): Ethernet cameras connect to the host PC via PoE/PoE+ switches using Cat 6, or above, Ethernet cables.
- Power the Switches: The switch must be powered in order to power the cameras. To completely shut down the camera system, the network switch needs to be powered off.
- Ethernet Cables: Ethernet cable connection is subject to the limitations of the PoE (Power over Ethernet) and Ethernet communications standards, meaning that the distance between camera and switch can go up to about 100 meters when using Cat 6 cables (Ethernet cable type Cat5e or below is not supported). For best performance, do not connect devices other than the computer to the camera network. Add-on network cards should be installed if additional Ethernet ports are required.
- External Sync: If you wish to connect external devices, use the eSync synchronization hub. Connect the eSync into one of the PoE switches using an Ethernet cable, or if you have a multi-switch setup, plug the eSync into the aggregation switch.
Click image to enlarge.
- Uplink Switch: For systems with higher camera counts that uses multiple PoE switches, use an uplink Ethernet switch to link and connect all of the switches to the Host PC. In the end, the switches must be connected in a star topology with the uplink switch at the central node connecting to the host PC. NEVER daisy chain multiple PoE switches in series because doing so can introduce latency to the system.
- High Camera Counts: For setting up more than 24 Prime series cameras, we recommend using a 10 Gigabit uplink switch and connecting it to the host PC via an Ethernet cable that supports 10 Gigabit transfer rate — Cat6a or above. This will provide larger data bandwidth and reduce the data transfer latency.
Click image to enlarge.
- PoE switch requirement: The PoE switches must be able to provide 15.4W power to every port simultaneously. PrimeX 41, PrimeX 22, and Prime Color camera models run on a high power mode to achieve longer tracking ranges, and they require 30W of power from each port. If you wish to operate these cameras at standard PoE mode, set the LLDP (PoE+) Detection setting to false under the application settings. For network switches provided by OptiTrack, refer to the label for the number of cameras supported for each switch.
Optical motion capture systems utilize multiple 2D images from each camera to compute, or reconstruct, corresponding 3D coordinates. For best tracking results, cameras must be placed so that each of them captures unique vantage of the target capture area. Place the cameras circumnavigating around the capture volume, as shown in the example below, so that markers in the volume will be visible by at least two cameras at all times. Mount cameras securely onto stable structures (e.g. truss system) so that they don't move throughout the capture. When using tripods or camera stands, ensure that they are placed in stable positions. After placing cameras, aim the cameras so that their views overlap around the region where most of the capture will take place. Any significant camera movement after system calibration may require re-calibration. Cable strain-relief should be used at the camera end of camera cables to prevent potential damage to the camera.
In order to obtain accurate and stable tracking data, it is very important that all of the cameras are correctly focused to the target volume. This is especially important for close-up and long-range captures. For common tracking applications in general, focus-to-infinity should work fine, however, it is still important to confirm that each camera in the system is focused.
To adjust or to check camera focus, place some markers on the target tracking area. Then, set the camera to raw grayscale mode, increase the exposure and LED settings, and then Zoom onto one of the retroreflective markers in the capture volume and check the clarity of the image. If the image is blurry, adjust the camera focus and find the point where the marker is best resolved.
Out of focus
Moderately in focus
In order to properly run a motion capture system using Motive, the host PC must satisfy the minimum system requirements. Required minimum specifications vary depending on sizes of mocap systems and types of cameras used. Consult our Sale Engineers, or use the Build Your Own feature on our website to find out host PC specification requirements.
Motive is a software platform designed to control motion capture systems for various tracking applications. Motive not only allows the user to calibrate and configure the system, but it also provides interfaces for both capturing and processing of 3D data. The captured data can be recorded or live-streamed into other pipelines.
Motive Activation Requirements
The following items will be required for activating Motive. Please note that the valid duration of the Motive license must be later than the release date of the version that you are activating. If the license is expired, please update the license or use an older version of Motive that was released prior to the license expiration date.
- Motive 3.x license
- USB Security Key
Host PC Requirements
Required PC specifications may vary depending on the size of the camera system. Generally, you will be required to use the recommended specs with a system with more than 24 cameras.
Download and Install
License Activation Steps
- 1.Insert the USB Security Key into a USB-C port on the computer. If needed, you can also use a USB-A adapter to connect.
- 2.Launch Motive
- 3.Activate your software using the License Tool, which can be accessed in the Motive splash screen. You will need to input the License Serial Number and the Hash Code for your license.
By default, Motive will start on the calibration layout with all the necessary panes open. Using this layout, you can calibrate the camera system and construct a 3D tracking volume. The layout may be slightly different for certain camera models or software licenses.
The following panes will be open:
Now that the cameras are connected and showing up in Motive, the next step is to configure the camera settings. Appropriate camera settings will vary depending on various factors including the capture environment and tracked objects. The overall goal is to configure the settings so that the marker reflections are clearly captured and distinguished in the 2D view of each camera. For a detailed explanation on individual settings, please refer to the Devices pane page.
To check whether the camera setting is optimized, it is best to check both the grayscale mode images and tracking mode (Object or Precision) images and make sure the marker reflection stands out from the image. You switch a camera into grayscale mode either in Motive or by using the Aim Assist button for supported cameras. In Motive, you can right-click on the Cameras Viewport and switch the video mode in the context menu, or you can also change the video mode through the Properties pane.
The exposure setting determines how long the camera imagers are exposed per each frame of data. With longer the exposure, more light will be captured by the camera, creating the brighter images that can improve visibility for small and dim markers. However, high exposure values can introduce false markers, larger marker blooms, and marker blurring – all of which can negatively impact marker data quality. It is best to minimize the exposure setting as long as the markers are clearly visible in the captured images.
Adjusting camera settings using the Devices pane. This can also be done through the Properties pane as well.
Retroreflective markers shown on the grayscale image.
In order to start tracking, all cameras must first be calibrated. Through the camera calibration process, Motive computes position and orientation of cameras (extrinsic) as well as amounts of lens distortions in captured images (intrinsics). Using the calibration results, Motive constructs a 3D capture volume, and within this volume, motion tracking is accomplished. All of the calibration tools can be found under the Calibration pane. Read through the Calibration page to learn about the calibration process and what other tools are available for more efficient workflows.
Starting a Calibration
To start a system calibration, open the Calibration Pane. Under the Calibration pane, you can choose to start a new calibration or to modify the existing one. For this guide, click New Calibration for a fresh calibration.
Starting a new calibration.
Before the system calibration, any extraneous reflections or unnecessary markers should ideally be removed or covered so that they are not seen by the cameras. However, it may not always be possible to remove all of them. In this case, these extraneous reflections can be ignored by applying masks over them during the calibration.
- 1.Check the calibration pane to see if any of the cameras are seeing extraneous reflections or noise in their view. A warning sign will appear over these cameras.
- 2.Check the camera view of the corresponding camera to identify where the extraneous reflection is coming from, and if possible, remove them from the capture volume or cover them so that the cameras do not see them.
- 3.If reflections still exist, click Mask to automatically apply masks over all of the reflections detected in the camera views.
- 4.Once all of the reflections have been masked or removed, click Continue to proceed to the wanding step.
Masking in camera view.
In the wanding stage, we will use the Calibration Wand to collect wanding samples that will be used for calibrating the system.
Performing calibration wanding for a system with 6 cameras
- 2.Under the Wand settings, specify the wand that you will be used to calibrate the volume. It is very important to input the matching wand size here. When an incorrect dimension is given to Motive, the calibrated 3D volume will be scaled incorrectly.
- 3.Click Start Wanding to start collecting the wanding sample.
- 4.Once the wanding process starts. Bring your calibration wand into the capture volume and start waving the wand gently across the entire capture volume. Gently draw figure-eight repetitively with the wand to collect samples at varying orientations and cover as much space as possible for sufficient sampling. Wanding trails will be shown in colors on the 2D View. A grid/table displaying the status of the wanding process will show up in the Calibration pane to monitor the progress.
- 5.As each camera collects the wanding samples, the camera grid representing the wanding status of each camera will start changing its color to bright green. This provides visual feedback on whether sufficient samples have been collected by each camera. Wave the wand until all boxes are filled with bright green color.
- 6.Once enough samples have been collected, press the Start Calculation button to start calibrating. The calculation may take a few minutes to complete.
- 7.When the calculation is finished, its results will get displayed. If the overall result is acceptable, click Continue to proceed to setting up the ground. If the result is not satisfactory, click Cancel and go through the wanding once more.
Setting the Ground Plane
Now that all of the cameras have been calibrated, the next step is to define the ground plane of the capture volume.
CS-400 calibration square
- 2.Orient the calibration square so that the longer arm is directed towards the desired +Z axes and the shorter arm is directed towards the desired +X axes of the volume. Motive uses the y-up right-hand coordinate system.
- 3.Level the calibration square parallel to the ground plane.
- 4.At this point, the Calibration pane should detect which calibration square has been placed in the tracking volume. If not, you may want to specifically select the three markers on the calibration square from the 3D view in Motive.
- 5.Click Set Ground Plane to complete the calibration.
Once the camera system has been calibrated, Motive is ready to collect data. But before doing so, let's prepare the session folders for organizing the capture recordings and define the trackable assets, including Rigid Body and/or Skeletons.
Each capture recording will be saved in a Take (TAK) file and related Take files can be organized in session folders. Start your capture by first creating a new Session folder. Create a new folder in the desired directory of the host computer and load the folder onto the Data pane by either clicking on the
icon OR just by drag-and-dropping them onto the data management pane. If no session folder is loaded, all of the recordings will be saved onto the default folder located in the user documents directory (Documents\OptiTrack\Default). All of the newly recorded Takes will be saved within the currently selected session folder which will be marked with the
Session folders loaded in the Data Management pane
An example session folder in Windows File Explorer.
Motive's software configurations are saved to Motive Profiles (*.motive extension). All of the application-related settings can be saved into the Motive profiles, and you can export and import these files and easily maintain the same software configurations.
Place the retro-reflective markers onto subjects (Rigid Body or Skeleton) that you wish to track. Double-check that the markers are attached securely. For skeleton tracking, open the Builder pane, go to skeleton creation options, and choose a marker set you wish to use. Follow the skeleton avatar diagram for placing the markers. If you are using a mocap suit, make sure that the suit fits as tightly as possible. Motive derives the position of each body segment from related markers that you place on the suit. Accordingly, it is important to prevent the shifting of markers as much as possible. Sample marker placements are shown below.
Retroreflective markers placed on a quadrocopter
The corresponding Rigid Body defined in Motive
Markers placed for a subject.
Markers placements shown for Baseline (41) skeleton shown in the Builder pane.
Create Rigid Body
To define a Rigid Body, simply select three or more markers in the Perspective View, right-click, and select Rigid Body → Create Rigid Body From Selected. You can also utilize CTRL+T hotkey for creating Rigid Body assets. You can also use the Builder pane to define the Rigid Body.
To define a skeleton, have the actor enter the volume with markers attached at appropriate locations. Open the Builder pane and select Skeleton and Create. Under the marker set section, select a marker set you wish to use, and a corresponding model with desired marker locations will be displayed. After verifying that the marker locations on the actor correspond to those in the Builder pane, instruct the actor to strike the calibration pose. Most common calibration pose used is the T-pose. The T-pose requires a proper standing posture with back straight and head looking directly forward. Then, both arms are stretched to sides, forming a “T” shape. While in T-pose, select all of the markers within the desired skeleton in the 3D view and click Create button in the Builder pane. In some cases, you may not need to select the markers if only the desired actor is in view.
Using Builder pane to define a skeleton
Once the volume is calibrated and skeletons are defined, now you are ready to capture. In the Control Deck at the bottom, press the dimmed red record button or simply press the spacebar when in the Live mode to begin capturing. This button will illuminate in bright red to indicate recording is in progress. You can stop recording by clicking the record button again, and a corresponding capture file (TAK extension), also known as capture Take, will be saved within the current session folder. Once a Take has been saved, you can playback captures, reconstruct, edit, and export your data in a variety of formats for additional analysis or use with most 3D software.
When tracking skeletons, it is beneficial to start and end the capture with a T-pose. This allows you to recreate the skeleton in post-processing when needed.
After capturing a Take. Recorded 3D data and its trajectories can be post-processed using the Data Editing tools, which can be found in the Edit Tools pane. Data editing tools provide post-processing features such as deleting unreliable trajectories, smoothing select trajectories, and interpolating missing (occluded) marker positions. Post-editing the 3D data can improve the quality of tracking data.
General Editing Steps
- 1.Skim through the overall frames in a Take to get an idea of which frames and markers need to be cleaned up.
- 3.Select a marker that is often occluded or misplaced.
- 5.For each gap in frames, look for an unlabeled marker at the expected location near the solved marker position. Re-assign the proper marker label if the unlabeled marker exists.
- 6.Use Trim Tails feature to trim both ends of the trajectory in each gap. It trims off a few frames adjacent to the gap where tracking errors might exist. This prepares occluded trajectories for Gap Filling.
- 7.Find the gaps to be filled, and use the Fill Gaps feature to model the estimated trajectories for occluded markers.
- 8.Re-Solve assets to update the solve from the edited marker data
Markers detected in the camera views get trajectorized into 3D coordinates. The reconstructed markers need to be labeled for Motive to distinguish different trajecectories within a capture. Trajectories of annotated reconstructions can be exported individually or used (solved altogether) to track the movements of the target subjects. Markers associated with Rigid Bodies and Skeletons are labeled automatically through the auto-labeling process. Note that Rigid Body and Skeleton markers can be auto-labeled both during Live mode (before capture) and Edit mode (after capture). Individual markers can also be labeled, but each marker needs to be manually labeled in post-processing using assets and the Labeling pane. These manual Labeling tools can also be used to correct any labeling errors. Read through the Labeling page for more details in assigning and editing marker labels.
- Auto-label: Automatically label sets of Rigid Body markers and skeleton markers using the corresponding asset definitions.
Unlabeled passive markers displayed in white. Color settings can be adjusted from the Application Settings.
Labeled skeleton markers displayed in assigned color. Marker colors and sticks can be modified using Constraints pane.
Labeled Rigid Body markers displayed in assigned color. Rigid Body colors can be adjusted from the Rigid Body properties.
Motive exports reconstructed 3D tracking data in various file formats, and exported files can be imported into other pipelines to further utilize capture data. Supported formats include CSV and C3D for Motive: Tracker, and additionally, FBX, BVH, and TRC for Motive: Body. To export tracking data, select a Take to export and open the export dialog window, which can be accessed from File → Export Tracking Data or right-click on a Take → Export Tracking data from the Data pane. Multiple Takes can be selected and exported from Motive or by using the Motive Batch Processor. From the export dialog window the frame rate, measurement scale, and frame range of exported data can be configured. Frame ranges can also be specified by selecting a frame range in the Graph View pane before exporting a file. In the export dialog window, corresponding export options are available for each file format.
Tracking data export dialogue window in Motive. CSV export is selected and corresponding export options are listed. Click image to enlarge.
Motive offers multiple options to stream tracking data onto external applications in real-time. Tracking data can be streamed in both Live mode and Edit mode. Streaming plugins are available for Autodesk Motion Builder, Visual3D, The MotionMonitor, Unreal Engine 4, 3ds Max, Maya (VCS), and VRPN, and they can be downloaded from the OptiTrack website. For other streaming options, the NatNet SDK enables users to build custom client and server applications to stream capture data. Common motion capture applications rely on real-time tracking, and the OptiTrack system is designed to deliver data at an extremely low latency even when streaming to third-party pipelines. Detailed instructions on specific streaming protocols are included in the PDF documentation that ships with the respective plugins or SDK's.
Data Streaming in Motive allows you to stream capture data into other applications.