This page provides instructions on setting up the OptiTrack OpenVR driver for integrating OptiTrack system with Vive HMDs within SteamVR applications; including Unreal Engine and Unity.
For integrating Vive / Vive Pro / Valve Index HMDs, the OptiTrack OpenVR Driver must be used. This driver lets you track the head-mounted display (HMD) and the VR controllers using OptiTrack motion capture system and stream the tracking data from Motive directly into SteamVR. In other words, this will basically override the tracking from the lighthouse stations. The plugin ships as an installer package (MSI) which will set up the driver along with a utility tool for configuring client streaming settings. Once integrated, the streamed tracking data can be used in any application platform that utilizes SteamVR. For tracking of objects other than the HMDs, please read through the OptiTrack Unity Plugin page for details.
VIVE
VIVE Pro 1/2
Valve Index
HP Reverb G2
First of all, setup and optimize the motion capture volume as explained in the Getting Started guide or the Hardware Setup documentation. If you plan to install any obstacles (e.g. walls) within the capture volume, make sure they are non-reflective, and place and orient the cameras so that every corner is thoroughly captured by multiple cameras.
General Setup Steps
Attach the markers on the HMD
Create a Rigid Body asset
Calibrate the Pivot Point of the Rigid Body
Configure the Rigid Body settings in Motive
For the camera system to track the HMD, a set of markers must be attached to the HMD. You can either use the active markers (Active HMD clip or Active Tags) or the passive markers. Passive markers are retroreflective markers that reflect infrared light emitted from the IR LEDs on the camera. On the other hand, the active markers are LED markers that emit the IR light and has the intelligence to be uniquely identified.
In general, for most VR applications, using active markers is recommended for better tracking stability and ease of use. Active markers also have advantages over passive markers when tracking a large number of objects. For applications that are sensitive to the accuracy of the tracking data, using passive marker may have more benefits. To get more help with finding the best solution for your tracking application, please contact us.
When using the active markers, you can conveniently put a set of 8 markers onto the HMD by using the HMD Clip, or you can attach the markers from the Tag manually onto the HMD using adhesives and marker posts.
Active HMD Clip
Active HMD Clip is an HMD enclosure with a total of 8 active markers embedded for tracking. At the time of writing, there are active HMD clips for Vive Pro / Valve Index HMDs available on the webstore. The clips can be mounted easily by pushing it onto the HMD until the latches click, and you can detach it by gently lifting the three latches located at the top, left, and right side of the clip.
Once the clip has been mounted, next step is to import the provided Rigid Body asset into Motive and refine the definition to get the calibrated pivot point position and orientation, which will be explained on the next section.
Marker Types
You can either use the passive retro-reflective type markers or the active LED markers to track the HMD. Passive markers are retroreflective markers that reflect infrared light emitted from the IR LEDs on the camera. On the other hand, the active markers are LED markers that emit the IR light which gets uniquely identified in Motive. Either type of marker can be used to track HMDs. Using active marker is recommended especially for applications that involve tracking of multiple HMDs in the scene.
Marker Placement
Make sure the markers are attached securely and do not move. If the markers happen to move even slightly after a Rigid Body is defined, it will negatively affect the tracking and the Rigid Body definition may need to be updated.
Avoid placing multiple markers in close vicinity as they may overlap in the camera view in certain orientations.
Using marker posts to extend out the markers is recommended to improve marker visibility from more angles.
If you are using the active markers, there is an extra USB port on the HMD that you could draw the power from.
Please read through the Rigid Body Tracking page for additional information on the marker placement on a Rigid Body.
This feature can be used only with HMDs that have the OptiTrack Active HMD clips mounted.
For using OptiTrack system for VR applications, it is important that the pivot point of HMD Rigid Body gets placed at the appropriate location, which is at the root of the nose in between the eyes. When using the HMD clips, you can utilize the HMD creation tools in the Builder pane to have Motive estimate this spot and place the pivot point accordingly. It utilizes known marker configurations on the clip to precisely positions the pivot point and sets the desired orientation.
HMDs with passive markers can utilize the External Pivot Alignment tool to calibrate the pivot point.
First of all, make sure Motive is configured for tracking active markers.
Open the Builder pane under View tab and click Rigid Bodies.
Under the Type drop-down menu, select HMD. This will bring up the options for defining an HMD Rigid Body.
If the selected marker matches one of the Active clips, it will indicate which type of Active Clip is being used.
Under the Orientation drop-down menu, select the desired orientation of the HMD. The orientation used for streaming to Unity is +Z forward and Unreal Engine is +X forward, or you can also specify the expected orientation axis on the client plugin side.
Hold the HMD at the center of the tracking volume where all of the active markers are tracked well.
Select the 8 active markers in the 3D viewport.
Click Create. An HMD Rigid Body will be created from the selected markers and it will initiate the calibration process.
During calibration, slowly rotate the HMD to collect data samples in different orientations.
Once all necessary samples are collected, the calibrated HMD Rigid Body will be created.
This is supported only for Motive versions 2.1.2 or above. If you are using any other versions of Motive 2.1, please update the version to 2.1.2, or use a template to create the Rigid Body definition; instructions for which is provided in the following page: Using a Template File to Create Vive Pro Active Clip Rigid Body.
SteamVR Required: The VR driver streams tracking data through SteamVR. Please make sure SteamVR is installed on the computer before setting up the driver.
Download the OpenVR driver from the downloads page. Once downloaded, launch the installer and follow the prompts to set up the driver. On the last window, make sure to select Launch Configuration Utility before clicking Finish. This will open the Configuration options to setup your HMD with Motive.
You may receive a warning window prior to the installation wizard. To circumvent this, select More info and then Run Anyway.
Once the driver has been successfully installed, launch the configuration utility software (C:\Program Files\OptiTrack\OpenVR Driver\ConfigUtil). Using this tool, you can load and check existing configurations and make changes to the settings as needed. To import current settings, click Load and to save out the changes, click Save.
Please make sure you are running this tool with admin privileges; if not, it might not be able to modify the settings properly. If the configuration software detects a running instance of SteamVR through OpenVR, it will be indicated as Initialized at the very top as shown in the image. Please note that when the settings get modified while SteamVR is running, the SteamVR must be restarted to apply the changes.
First, configure the connection settings so that the driver listens to the Motive server where the tracking data is streamed from. The server address must match the address where Motive is streaming the data to, and the local address must match the IP address of the computer on the network where the driver is installed.
In the HMD section, enable the HMD and input the Rigid Body ID of the HMD. The Rigid Body ID must match the Streaming ID property of the HMD Rigid Body definition in Motive.
Save the configurations by clicking on Save. This will modify the set of configurations in the steamvr.settings file in the steam installation directory and they will override the HMD tracking with the tracking data from Motive. If you already had an instance of OpenVR or SteamVR running, restart the application to apply the changes.
Configuration File
The configuration tool basically imports and modifies the contents in the steamvr.settings file (C:\Program Files (x86)\Steam\config\steamvr.settings). When needed, the driver related settings can be changed directly from this file also, but it will be easier to configure the settings using the provided configuration tool.
Launch SteamVR. If the driver is successfully set up, you should see a tracker icon added to the right of the HMD icon and the HMD will now be using the motion capture system instead of the base stations. Here, please make sure all of the lighthouse base stations are powered off.
VIVE controllers are a Beta feature and may not work for every device. Support for this particular feature is limited.
Setting up the controller (optional)
When needed, the Vive controllers can be configured as well. To do so, open the configuration utility tool while SteamVR is running. At the top of the configuration tool, it should indicate OpenVR status as Initialized and the controllers must be showing up in SteamVR. Then, in the controller sections, enable the controllers, specify the override device using the drop-down menu, and input the corresponding streaming ID of the controller Rigid Bodies in Motive. Once everything has been configured, save the changes and restart SteamVR. When the override is configured properly, SteamVR will have an additional tracker icon per each enabled controller.
Now that the driver is set up, the HMD tracking will be overridden by tracking data from the mocap camera system, and you can integrate HMDs into the game engine through their own VR integration.
First, make sure the streaming settings are configured in Motive for streaming out the data. For more information on streaming in Motive please visit our Streaming page:
Broadcast Frame Data must be set to true.
Local interface must be set to the desired IP address to stream the tracking data from.
Streaming of Rigid Bodies must be set to True
For wireless streaming, use Unicast streaming type.
Once Motive is configured for streaming, launch SteamVR home to check the connection. If everything is setup correctly, you should be able to move around, or translate, within the scene freely. You may also need to check the ground plane to make sure it's well aligned.
If you experience any unexpected rotations in the view as you move your head, it could indicate that the HMD pivot point has not been calibrated properly. Please revisit the HMD Setup section and make sure the HMD Rigid Body pivot point is positioned and oriented at the expected pivot; which is at the root of nose with z-forward.
Once this has been set up, the motion capture system will be used to drive the HMD in SteamVR. In Unity, you should be able to setup development for SteamVR applications and use our system.
Starting from Unity version 2019 and above, official support for OpenVR in Unity has been deprecated. However, Valve made a plugin for the new Unity XR which can be used instead. Please follow the below steps to set up the Unity XR plugin and get the HMD working inside the Unity project:
OpenVR Unity XR plugin setup
1) Download the OpenVR Unity XR package found on the following Github page. 2) Download the OptiTrack OpenVR driver found on our website and configure the settings as described in the above section. 3) Open an Unity project 4) [Unity] Open the package manager from Window → Package manager. 5) [Unity] In the package manager, click on the "+" icon at the top and choose Add package from tarball. Then select the downloaded OpenVR Unity XR package.
6) [Unity] Check to make sure that the OpenVR XR plugin has been installed within your project.
7) [Unity] Now, follow the instructions on Unity's website to configure your project for XR development. Install the XR Plug-in manager which can be found under Edit → Project Setting → XR Plug-in Management.
8) [Unity] Enable the OpenVR Loader under the list of providers in the XR Plug-in Manager. If OpenVR Loader is not listed in there, make sure the plugin was installed properly from step 5) above.
9) [Unity] Once the plugin is configured, go to GameObject → XR → Add XR Rig.
10) Play the scene, and make sure the HMD is playing and tracking as well.
Please keep in mind that these steps are subject to change from Unity. You can find detailed instruction from the following page: https://docs.unity3d.com/Manual/configuring-project-for-xr.html
In Unity version 2018 and earlier, you can enable SteamVR by configuring the project setting. Please go to Edit → Project Settings → Player, open the XR Settings panel, and enable the Virtual Reality Supported property. You can also follow the instruction in the Unity Documentation:
This driver is designed for streaming of HMD and controller tracking data only. For streaming tracking data of other Rigid Body objects, you will need to use the corresponding plugins (Unreal Engine or Unity). In other words, the HMD tracking data will be streamed through the SteamVR using the driver you've installed, and all other tracking data will be streamed through the plugin.
Client Origin
When using the OpenVR driver along with the OptiTrack Unity Plugin for streaming of tracking data other than the HMD, such as Rigid Bodies and/or Skeletons, it is important that the OptiTrack Client Origin object is located at the global origin without any rotations. In other words, the position must be set to (0,0,0) and the rotation must be set to (0,0,0) on the client origin. This is important because the driver does not use the OptiTrack Unity Plugin but instead streams the HMD tracking data directly onto SteamVR through a separate channel.
This page provides instructions on setting up the for integrating OptiTrack system with Vive HMDs within SteamVR applications, including Unreal Engine and Unity.
For integrating Vive HMDs, the OptiTrack OpenVR Driver must be used. This driver lets you track the head-mounted display (HMD) and the VR controllers using OptiTrack motion capture system and stream the tracking data from Motive directly into SteamVR. In other words, this will basically override the tracking from the lighthouse stations. The plugin ships as an installer package (MSI) which will set up the driver along with a utility tool for configuring client streaming settings. Once integrated, the streamed tracking data can be used in any application platform that utilizes SteamVR. For tracking of objects other than the HMDs, please read through the page for details.
Supported Systems
Vive
Vive Pro 1/2
Valve Index
HP Reverb G2
When developing for SteamVR applications using the OpenVR Driver to track the HMD in Unreal Engine 4, the OptiTrack - Streaming Client version 2.27 must be used and the OptiTrack - VR Latency Optimization version 2.27 plugin is suggested. The OptiTrack - VR Latency Optimization provides HMD render compensation that helps to minimize the latency in VR application.
The latest plugins that support Unreal Engine 5 are OptiTrack - Live Link version 3.0 and OptiTrack - Streaming Client version 3.0.
General Setup Steps
Attach the markers on the HMD
Create a Rigid Body asset
Calibrate the Pivot Point of the Rigid Body
Configure the Rigid Body settings in Motive
For the camera system to track the HMD, a set of markers must be attached to the HMD. You can either use the active markers (Active HMD clip or Active Tags) or the passive markers. Passive markers are retroreflective markers that reflect infrared light emitted from the IR LEDs on the camera. On the other hand, the active markers are LED markers that emit the IR light and has the intelligence to be uniquely identified.
When using the active markers, you can conveniently put a set of 8 markers onto the HMD by using the HMD Clip, or you can attach the markers from the Tag manually onto the HMD using adhesives and marker posts.
Active HMD Clip
Active HMD Clip is an HMD enclosure with a total of 8 active markers embedded for tracking. At the time of writing, there are active HMD clips for Vive Pro / Valve Index HMDs available on the webstore. The clips can be mounted easily by pushing it onto the HMD until the latches click, and you can detach it by gently lifting the three latches located at the top, left, and right side of the clip.
Marker Types
Marker Placement
Make sure the markers are attached securely and do not move. If the markers happen to move even slightly after a Rigid Body is defined, it will negatively affect the tracking and the Rigid Body definition may need to be updated.
Avoid placing multiple markers in close vicinity as they may overlap in the camera view in certain orientations.
Using marker posts to extend out the markers is recommended to improve marker visibility from more angles.
If you are using the active markers, there is an extra USB port on the HMD that you could draw the power from.
For using OptiTrack system for VR applications, it is important that the pivot point of HMD Rigid Body gets placed at the appropriate location, which is at the root of the nose in between the eyes. When using the HMD clips, you can utilize the HMD creation tools in the Builder pane to have Motive estimate this spot and place the pivot point accordingly. It utilizes known marker configurations on the clip to precisely positions the pivot point and sets the desired orientation.
Steps
Under the Type drop-down menu, select HMD. This will bring up the options for defining an HMD Rigid Body.
If the selected marker matches one of the Active clips, it will indicate which type of Active Clip is being used.
Under the Orientation drop-down menu, select the desired orientation of the HMD. The orientation used for streaming to Unity is +Z forward and Unreal Engine is +X forward, or you can also specify the expected orientation axis on the client plugin side.
Hold the HMD at the center of the tracking volume where all of the active markers are tracked well.
Click Create. An HMD Rigid Body will be created from the selected markers and it will initiate the calibration process.
During calibration, slowly rotate the HMD to collect data samples in different orientations.
Once all necessary samples are collected, the calibrated HMD Rigid Body will be created.
SteamVR Required: The VR driver streams tracking data through SteamVR. Please make sure SteamVR is installed on the computer before setting up the driver.
You may receive a warning window prior to the installation wizard. To circumvent this, select More info and then Run Anyway.
Once the driver has been successfully installed, launch the configuration utility software (C:\Program Files\OptiTrack\OpenVR Driver\ConfigUtil). Using this tool, you can load and check existing configurations and make changes to the settings as needed. To import current settings, click Load and to save out the changes, click Save.
Please make sure you are running this tool with admin privileges; if not, it might not be able to modify the settings properly. If the configuration software detects a running instance of SteamVR through OpenVR, it will be indicated as Initialized at the very top as shown in the image. Please note that when the settings get modified while SteamVR is running, the SteamVR must be restarted to apply the changes.
First, configure the connection settings so that the driver listens to the Motive server where the tracking data is streamed from. The server address must match the address where Motive is streaming the data to, and the local address must match the IP address of the computer on the network where the driver is installed.
Save the configurations by clicking on Save. This will modify the set of configurations in the steamvr.settings file in the steam installation directory and they will override the HMD tracking with the tracking data from Motive. If you already had an instance of OpenVR or SteamVR running, restart the application to apply the changes.
Configuration File
The configuration tool basically imports and modifies the contents in the steamvr.settings file (C:\Program Files (x86)\Steam\config\steamvr.settings). When needed, the driver related settings can be changed directly from this file also, but it will be easier to configure the settings using the provided configuration tool.
Confirm the setup
Launch SteamVR. If the driver is successfully set up, you should see a tracker icon added to the right of the HMD icon and the HMD will now be using the motion capture system instead of the base stations. Here, please make sure all of the lighthouse base stations are powered off.
VIVE controllers are a Beta feature and may not work for every device. Support for this particular feature is limited.
When needed, the Vive controllers can be configured as well. To do so, open the configuration utility tool while SteamVR is running. At the top of the configuration tool, it should indicate OpenVR status as Initialized and the controllers must be showing up in SteamVR. Then, in the controller sections, enable the controllers, specify the override device using the drop-down menu, and input the corresponding streaming ID of the controller Rigid Bodies in Motive. Once everything has been configured, save the changes and restart SteamVR. When the override is configured properly, SteamVR will have an additional tracker icon per each enabled controller.
Now that the driver is set up, the HMD tracking will be overridden by tracking data from the mocap camera system, and you can integrate HMDs into the game engine through their own VR integration.
Enable must be set to toggled on.
Local interface must be set to the desired IP address to stream the tracking data from.
Streaming of Rigid Bodies must be set to True
For wireless streaming, use Unicast streaming type.
Once Motive is configured for streaming, launch SteamVR home to check the connection. If everything is setup correctly, you should be able to move around, or translate, within the scene freely. You may also need to check the ground plane to make sure it's well aligned.
If you experience any unexpected rotations in the view as you move your head, it could indicate that the HMD pivot point has not been calibrated properly. Please revisit the HMD Setup section and make sure the HMD Rigid Body pivot point is positioned and oriented at the expected pivot; which is at the root of nose with z-forward.
Make sure Unreal Engine is configured for SteamVR development. Please refer to the Unreal Engine's documentation for more information on developing for SteamVR.
Client Origin
When using the OpenVR driver for the HMD and the game engine plugins (UE/Unity) for other types of tracking data, including Rigid Body data, the client origin object must be located at the global origin without any rotations. In other words, the position must be set to (0,0,0) and the rotation must be set to (0,0,0) on the client origin. This is important because this will align the coordinate system from the (UE/Unity) plugin with the coordinate system in OpenVR pipeline
Notes for Unreal Engine Users
When using the Unreal Engine plugin, you will need to additionally create a custom pawn for properly aligning the coordinate systems between SteamVR and OptiTrack UE plugin:
Create a new pawn. Right-click in Content Browser, and from the context menu, select Blueprint → Blueprint Class → Pawn.
Load created Blueprint in the editor and add a camera component.
(optional) Double-check that the “Lock to HMD” property is set to true under the camera component properties in the details pane.
Select the pawn and set the “Base Eye Height” property to 0 in the details pane.
Compile the pawn then add it to the scene.
Select the pawn and set the “Auto Possess Player” to “Player 0”.
The HMD should now be working for Levels built for VR.
First of all, setup and optimize the motion capture volume as explained in the or the documentation. If you plan to install any obstacles (e.g. walls) within the capture volume, make sure they are non-reflective, and place and orient the cameras so that every corner is thoroughly captured by multiple cameras.
In general, for most VR applications, using active markers is recommended for better tracking stability and ease of use. Active markers also have advantages over passive markers when tracking a large number of objects. For applications that are sensitive to the accuracy of the tracking data, using passive marker may have more benefits. To get more help with finding the best solution for your tracking application, please .
Once the clip has been mounted, next step is to import the provided into Motive and refine the definition to get the calibrated pivot point position and orientation, which will be explained on the next section.
You can either use the passive retro-reflective type markers or the active LED markers to track the HMD. Passive markers are retroreflective markers that reflect infrared light emitted from the IR LEDs on the camera. On the other hand, the active markers are LED markers that emit the IR light which gets uniquely identified in Motive. Either type of marker can be used to track HMDs. Using is recommended especially for applications that involve tracking of multiple HMDs in the scene.
Please read through the page for additional information on the marker placement on a Rigid Body.
This feature can be used only with HMDs that have the clips mounted.
HMDs with passive markers can utilize the tool to calibrate the pivot point.
First, make sure Motive is configured for tracking .
Open the under and click Rigid Bodies.
Select the 8 active markers in the .
This is supported only for Motive versions 2.1.2 or above. If you are using any other versions of Motive 2.1, please update the version to 2.1.2, or use a template to create the Rigid Body definition; instructions for which is provided in the following page: .
Download the OpenVR driver from the page. Once downloaded, launch the installer and follow the prompts to set up the driver. On the last window, make sure to select Launch Configuration Utility before clicking Finish. This will open the Configuration options to setup your HMD with Motive.
In the HMD section, enable the HMD and input the Rigid Body ID of the HMD. The Rigid Body ID must match the property of the HMD Rigid Body definition in Motive.
First, make sure the streaming settings are configured in Motive for streaming out the data. For more information regarding streaming in Motive please visit our wiki page:
This driver is designed for streaming of HMD and controller tracking data only. For streaming tracking data of other Rigid Body objects, you will need to use the corresponding plugins ( or ). In other words, the HMD tracking data will be streamed through the SteamVR using the driver you've installed, and all other tracking data will be streamed through the plugin.
Create an "OptTrack Client Origin" to the scene and set the relevant connection info. Refer to the page for more information on setting up the client origin.
OpenVR Driver
This synchronization setup is not required for integrating HTC Vive with OptiTrack system. For integrating HTC Vive with OptiTrack system, please use the OptiTrack OpenVR Driver. This driver will completely override the tracking of an HTC Vive HMD so that the HMD can be tracked just using the OptiTrack system without the lighthouse base stations, and when using the OpenVR driver, synchronization between two systems is not necessary. This article is for specific applications where both lighthouse base station and the OptiTrack system must be running simultaneously.
Notes on the Sync Settings
The sync settings listed on this page have not been tested with the latest version of the firmware. This means that the appropriate sync offset value indicated on this page might not be correct. For integrating into SteamVR, please consider using OptiTrack OpenVR Driver to completely override the tracking.
This article provides instructions on how to synchronize an OptiTrack Motion Capture system with an HTC Vive virtual reality system, specifically the lighthouse base stations, to avoid overlapping of the infrared tracking lights. The HTC Vive system also uses infrared LEDs and lasers for tracking its head-mounted display (HMD) and controllers. When using an OptiTrack mocap system in conjunction with the HTC Vive system, the infrared tracking from the two systems can interfere with each other. For this reason, the two systems must be synchronized in a way so that the two different tracking lights do not temporally overlap. Currently, sync configurations with only OptiTrack Prime-series camera systems have been tested.
Let’s go through the synchronization setup. The following setup instructions assume that the two tracking base stations of the HTC Vive system are set to channel b and c and are optically synchronized. The channel b base station will serve as the master device for synchronizing the two systems. Sync out signal from the channel b station will feed into one of the input ports on the eSync 2, and a sync offset (specified in microseconds, or μs) will be applied to so that IR lights from the two systems don’t interfere with each other. The following section describes the instructions in detail.
Note:
The eSync 2 is required in order to synchronize HTC Vive lighthouses with the camera system.
Synchronization with Flex camera systems is not supported.
The base stations will synchronize optically in this setup. Refer to the respective documentation for more details on setting up the HTC Vive system. Set the tracking stations to channels b and c, so that they are optically synchronized (in the absence of a sync cable connection between them).
Refer to the Hardware Setup wiki pages for more details.
The sync output of the base stations use 3.5 mm stereo (TRS) cables, whereas the Input ports of the eSync 2 are BNC ports. You will need to use a stereo female to RCA male adapter (e.g. http://www.monoprice.com/product?p_id=5612) as well as an RCA-to-BNC adaptor (included with the eSync 2) to connect the channel b base station and the eSync 2 hub. After attaching the stereo to RCA adaptor, connect the red RCA cable into the eSync 2 using a BNC adapter, as shown in the following photo.
Open the Synchronization pane in Motive, and set the synchronization type to Custom Synchronization.
Set the Sync Input to Input 1, which was the input port of the eSync 2 where the sync cable was connected to. If the sync cable is properly connected and the HTC Vive system is properly working, the bottom signal monitor will display a frequency of approximately 60 Hz detected through the Input 1 port of the eSync 2. Note that this configuration will synchronize the OptiTrack camera system to the sync signal coming through the Input port.
Now that the OptiTrack system’s shutter timing is synchronized with the base stations of the HTC Vive system, you will need to introduce a sync offset to avoid overlapping of the tracking lights. The following list of offset sync parameters are tested to avoid the interference. Input these parameters into the Synchronization pane. If you wish to increase the final frame rate of the mocap system, you will need to apply a multiplier.
Final Frame Rate: 120 Hz
Sync Multiplier: 2
Sync Offset: 1780 μs
Final Frame Rate: 240 Hz
Sync Multiplier: 4
Sync Offset: 3150 μs
Notes on the Sync Settings
The sync settings listed on this page have not been tested with the latest version of the firmware. This means that the appropriate sync offset value indicated on this page might not be correct. For integrating into SteamVR, please consider using OptiTrack OpenVR Driver to completely override the tracking.
Press Apply to employ the sync configuration. The tracking IR lights from both systems will no longer interfere, and the HTC Vive components will be working properly and available in the SteamVR application.
Another important note is that high camera exposure settings may cause IR light from the base stations to be detected by the OptiTrack system. It's suggested to keep the camera exposure below 1000 us for all of the cameras.
Now that the two systems are synchronized to avoid the IR interference, both systems can be used together to provide immersive VR experiences. Note that the instructions listed on this page are tested to work with HTC Vive system, but alternative approaches may also be possible.
This page covers manual positioning of HMD Rigid Bodies in Motive. This is an old workflow that a bit of time and effort to set up. With the HMD Calibration tool, you can create and auto-calibrate the HMD Rigid Bodies much easier and faster.
When manually positioning the appropriate location of the Rigid Body pivot point, you will need to have landmark markers on specific locations.
When attaching retroreflective markers, make sure markers are securely attached and readily captured by the cameras. For attaching the markers, we recommend using our 20 mm wide and 30 mm tall M4 threaded plastic marker bases with Acrylic adhesives, available at the webstore, to attach the markers onto the HMD.
A markered HMD will be defined as a Rigid Body in Motive. When placing markers, make sure the placement asymmetry is respected in the arrangement within the HMD. Also, the marker arrangements between multiple HMDs must be incongruent. For more details, read about marker placement from the Rigid Body Tracking page. Also, for tracking the HMD, two landmark markers must be placed in the following locations:
Eye-level Side Markers (2)
Place two markers on left and right side of the HMD, these markers will serve two additional purposes. First, they will indicate yaw of the HMD, and they will be used to align the Rigid Body orientation with the orientation of the actual HMD component. Thus, a line interconnecting the two markers must be parallel to the frontal plane, or the display, of the HMD. Second, these markers will be used to locate the elevation of the eyes when creating the Rigid Body in Motive. In summary, the two landmark markers must be carefully placed considering the following:
The markers should align along eye-level of the user when the HMD is mounted.
Most importantly, place these markers in the exactly same location of the left and right side so that they form a precisely symmetrical arrangement.
Same dimension attachment bases must be used for both of the markers.
For best virtual experiences, the pivot point of the HMD Rigid Body, in Motive, needs to be positioned on the midpoint between two eyes, of the user when the HMD is put on. To locate this, use the side and top-center landmark markers as references. For more information on adjusting Rigid Body pivot points, please read through the Rigid Body Tracking page.
Gizmo Tool: Translate, Rotate, and Scale
For Motive versions 2.1 and above, setting pivot point location is much easier using the GIZMO tools. Instructions on adjusting pivot point location using the GIZMO tool is detailed in the following page: Gizmo Tool: Translate, Rotate, and Scale. Using this tool, you can select markers in the 3D viewport and easily place the Rigid Body pivot point onto a specific landmark marker, or onto a midpoint between the selected markers.
1. Set the pivot point over the landmark marker. Use the Set Pivot Point to Selected Marker feature to assign the pivot point to the marker. This will set the elevation of the pivot point along the eye-level.
3. Translate the pivot point along the z-axis using the translation tool. For the most accurate position, you may need to physically measure the sagittal, z-axis, distance from the landmark marker to the root of nose, and apply the measured offset.
Now that you have translated the pivot point, you need to make detailed adjustments to the orientation using the orientation transformation tool. For best results, align the two front markers along the x-axis grid and roughly center the Rigid Body along the z-axis grid. Then, check to make sure that each of the Rigid Body orientation axes is parallel to the grids lines in Motive. If there is any deviation, apply rotation to adjust the offset. If needed, transparency of the axes and the grids can be adjusted from the Application settings.
In Unreal Engine: the X-axis of the HMD Rigid Body must be directed forward.
In Unity: the Z-axis of the HMD Rigid Body must be directed forward.
Tip: Once you have the Rigid Body asset for the HMD configured, you can export the asset into a TRA file for future uses. Importing the TRA file (e.g. CV1.tra) will load the Rigid Body (HMD) asset and make it available for use; however, the marker placement must remain unchanged in order to re-load previously created Rigid Bodies.
2. Place the pivot point at the midpoint between the two markers. Enable Two Marker Distance visual aid from the perspective pane, and select the two landmark markers in Motive. This will provide a distance between two markers. Then, using this information, translate the pivot point laterally by half of the distance so that it is placed right on the midpoint between two markers.
