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.

Hardware Setup

Preparing the Capture Area

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.

See Also: Hardware Setup workflow pages.

Cabling and Load Balancing

Ethernet Camera System

Ethernet Camera Models: PrimeX series and SlimX 13 cameras. Follow the below wiring diagram and connect each of the required system components.

See Also: Network setup page.

Placing and Aiming Cameras

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.

See Also: Camera Placement and Camera Mount Structures pages.

Lens Focus

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.

See Also: Aiming and Focusing page.

Software Setup

Host PC Requirements

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 Installation

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.

If you are new to Motive, we recommend you to read through Motive Basics page after going through this guide to learn about basic navigation controls in Motive.

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 2.x license

• USB Hardware 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

To install Motive, simply download the Motive software installer for your operating system from the Motive Download Page, then run the installer and follow its prompts.

Install Requirements

The first time Motive 2.3.x is installed on a computer, the following software also needs to be installed:

• Microsoft Visual C++ Redistributables 2013 and 2015

• Microsoft DirectX 9c

• OptiTrack USB Drivers

License Activation Steps

1. Insert the USB Hardware Key into a USB-A 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.

4. After activation, the License tool will place the license file associated to the USB Security Key in the License folder. For more license activation questions, visit Licensing FAQs or contact our Support.

First Launch

When you first launch Motive, the Quick Start panel will show up, and you can use this panel to quickly get started on specific tasks. By default, Motive will start on the Calibration Layout. Using this layout, you can calibrate the camera system and construct a 3D tracking volume. Note that the initial layout may be slightly different for different camera models or software licenses.

The following table briefly explains purposes of some of the panels on the initial layout:

Viewport Navigation

Use the following controls for navigating throughout the 2D and 3D viewports in Motive. Most of the navigation controls are customizable, including both mouse and Hotkey controls. The Hotkey Editor Pane and the Mouse Control Pane under the Edit tab allow you to customize mouse navigation and keyboard shortcuts to common operations.

Camera Settings

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.

Exposure Setting

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.

System Calibration

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.

See Also: Calibration page.

Calibration Steps

Masking

1. Remove any unwanted objects and physically cover any extraneous IR light reflections or interferences within the capture volume.

2. [Motive:Calibration pane] In Motive, open the Calibration pane or use the calibration layout (CTRL + 1).

Wanding

1. Bring out the calibration wand.

2. [Motive:Calibration pane] From the Calibration pane, make sure the Calibration Type is set to Full and the correct type of the wand is specified under the OptiWand section.

3. [Motive:Calibration pane] Click Start Wanding to begin wanding.

4. Bring the wand into the capture volume, and wave the wand throughout the volume and allow cameras to collect wanding samples.

5. [Motive:Calibration pane] When the system indicates enough samples have been collected, click the Calculate button to begin the calculation. This may take few minutes.

6. [Motive:Calibration pane] When the Ready to Apply button becomes enabled, click Apply Result.

7. [Motive] Calibration results window will be displayed. After examining the wanding result, click Apply to apply the calibration.

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.

1. Now that all of the cameras have been calibrated, you need to define the ground plane of the capture volume.

2. Place a calibration square inside the capture volume. Position the square so that the vertex marker is placed directly over the desired global origin.

3. 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.

4. Level the calibration square parallel to the ground plane.

5. (Optional) In the 3D view in Motive, select the calibration square markers. If retro-reflective markers on the calibration square are the only reconstructions within the capture volume, Motive will automatically detect the markers.

6. Access the Ground Plane tab in the Calibration pane.

7. While the calibration square markers are selected, click Set Ground Plane from the Ground Plane Calibration Square section.

8. Motive will prompt you to save the calibration file. Save the file to the corresponding session folder.

Capture Setup

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.

Set Up for Capture Session

Motive Recordings

See Also: Motive Basics page.

Motive Profiles

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.

Marker Up

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.

See Also: Markers page for marker types, or Rigid Body Tracking and Skeleton Tracking page for placement directions.

Define Skeletons and Rigid Bodies

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.

Create Skeleton

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.

See Also: Rigid Body Tracking page and Skeleton Tracking page.

Record Data

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.

See Also: Data Recording page.

Post-Capture

Data Editing

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.

2. Refer to the Labels pane and inspect gap percentages in each marker.

3. Select a marker that is often occluded or misplaced.

4. Look through the frames in the Graph pane, and inspect the gaps in the trajectory.

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

Marker Labeling

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.

• Manual Label: Labeling individual markers manually using the Labeling, assigning labels defined in the Marker Set, Rigid Body, or Skeleton assets.

See Also: Labeling page.

Data Export

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.

See Also: Data Export page.

Data Streaming

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 5, 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.

See Also: Data Streaming page