yarp-openvr-trackers

YARP OpenVR Trackers project allows to stream OpenVR based tracker poses over a YARP Frame Transform Server.

The installation and usage procedure was tested with Windows 10 OS.

Prerequisites

Install Visual Studio

If you do not already have Visual Studio installed on your machine, you can install it using the Visual Studio Installer by enabling Desktop and Mobile C++ development package. This can be enabled by clicking on the Modify button in the installer corresponding to the desired installation.

Install Steam and SteamVR

Install Steam
After installation, either create a Steam account or use an existing one to log-in and install SteamVR.

Install robotology-superbuild

We rely on YARP for the use of yarp-openvr-trackers. If YARP is not already installed on your Windows machine, we recommend to install YARP using robotology-superbuild. robotology-superbuild can be installed either from source or using binaries with its dependencies installed using Package environment system called Conda following the installation procedure here. Subsequently, robotology-superbuild can be installed from source or using binaries by following the installation procedure here.

While following the installation procedure using Conda-forge based dependencies, you create an environment within which the packages are installed. So everytime, we open a new terminal we need to activate this environment in order to access the installed dependencies and installed packages from the robotology-superbuild. Note that, if you have followed a Source-based installation in installation procedure here, your environment needs to be activated using,

mamba activate robsub

while, if you have followed the binary installation procedure in installation procedure here, you have to use,

mamba activate robotologyenv

Note that this may not apply if you have installed YARP or robotology-superbuild following any other custom installation procedures.

Other dependencies

Install git and PkgConfig.

mamba install -c conda-forge  git pkg-config

OpenVR and yarp-openvr-trackers

Install OpenVR

We install OpenVR using a custom fork from ami-iit organization because of some custom patches from the original repository. We clone, build, and install the repository from fix_upstream branch (which is the default branch of the fork).

git clone -b fix_upstream https://github.com/ami-iit/openvr
cd openvr
mkdir build
cd build
cmake -G "Visual Studio 17 2022" -DCMAKE_INSTALL_PREFIX:PATH=<full-absolute-path-to-where-you-want-to-install-openvr> -DBUILD_SHARED=ON ..
cmake --build . --config Release
cmake --install . --config Release

⚠️ WARNING: It is recommended to mention a custom location for CMAKE_INSTALL_PREFIX that does not require administrator privileges. ⚠️ WARNING: It is recommended to specify an absolute path to the install location in order to avoid strange, unresolved behaviors. ⚠️ WARNING: It must be noted that the configuration tag Visual Studio 17 2022 applies for a Visual Studio 2022 Installation. Previous versions of installation should use corresponding tags, such as Visual Studio 16 2019 for a 2019 installation

NOTE: The CMake option BUILD_SHARED needs to be set to ON on Windows, while on Linux/macOS it can be left to be OFF.

NOTE: Since we are using the conda environment for installation, a common trick to avoid having to set new environment variables is just to install the CMake project directly in the environment, i.e. passing -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX on Linux/macOS or -DCMAKE_INSTALL_PREFIX=%CONDA_PREFIX%\Library on Windows.

Add OpenVR package to Package Configuration Path

To have OpenVR installation to be identified by CMake, we need to add it to the package configuration path. This can be done from the terminal after activating the mamba environment by,

set PKG_CONFIG_PATH=%PKG_CONFIG_PATH%;<path_to_openvr-install-location>/share/pkgconfig

To verify if the package is properly added to the path, we may run

pkg-config --list-all

and check for openvr in the list of packages displayed.

Install yarp-openvr-trackers

We install yarp-openvr-trackers

git clone https://github.com/ami-iit/yarp-openvr-trackers.git
cd yarp-openvr-trackers
mkdir build
cd build
cmake -G "Visual Studio 17 2022" -DCMAKE_INSTALL_PREFIX:PATH=<full-absolute-path-to-where-you-want-to-install-yarp-openvr-trackers> ..
cmake --build . --config Release
cmake --install . --config Release

Adjust firewall settings for YARP

In order to properly use YARP across the network, we have to provide firewall access to the YARP executables. To do this,

Go to Control Panel -> System and Security -> Windows Defender Firewall -> Allowed apps
You must be on Firewall and network protection page in the Windows Security section. Click on Allow an app through firewall
Click on Change settings to have administrator privilege.
Scroll down to find yarp.exe in the list and select Details...->Network types... and check all the network types (Domain, Public, and Private) and click Ok.
Then we may have to repeat the procedure for yarpdev, yarp-server, and yarp-openvr-trackers using Allow another app... button.

Checking the hardware setup

Place the base stations in desired locations and power them on.
Connect the Vive headset to the PC. (At this moment, connecting a headset is required to use SteamVR, in the future we need to find a workaround to avoid connecting the headset). It must be noted that the trackers pose are obtained relative to the Vive headset.
Ensure that PC connecting the headset is not connected to an external display/monitor. Otherwise, the display is extended into the headset and is not identified by SteamVR. With only the headset connected to the PC, ensure that the displays are extended (Display settings -> Extend the displays).
Now, SteamVR should identify the base station and the headset.
Once the headset is properly identified, it prompts you to update Bluetooth driver settings and enable direct display mode. Follow the procedures.
The settings for the headset will be displayed. Go to Settings->General and disable SteamVR home.
We then have to follow a calibration procedure indicated by SteamVR to set the seated position and floor position.
In order to see what the user views through the headset, click on the menu button on SteamVR app and select Display VR View.
In order to pair the Vive trackers, select Menu->Devices->Pair Controllers and select the Vive tracker to follow the pairing procedure.
If the trackers are properly paired, you must see them through the headset.

Running yarp-openvr-trackers

Now, in order to obtain the pose of the trackers through the YARP network, we will run the following commands.

Run yarpserver in a new mamba activated terminal.
Run transformServer in a new mamba activated terminal,

yarpdev --device transformServer --ROS::enable_ros_publisher 0 --ROS::enable_ros_subscriber 0

Run yarp-openvr-trackers

yarp-openvr-trackers

To verify the transforms are being published,

yarp read ... /transformServer/transforms:o

This must display the name of the headset and the marker name along with the poses in quaternion and position format.

Note

You can pass the "Tracking universe" as a parameter to yarp-openvr-trackers by running the executable with the option --vrOrigin. For example:

yarp-openvr-trackers --vrOrigin standing

The value standing can be chagnged to seated or raw, and it's case insensitive. The default origin seated will be used when no parameter is passed or when passing an invalid value.

Trackers roles

From SteamVR, it is possible to assign a "role" to a tracker via the "Manage Trackers" menu.

⚠️ When using the HELD IN HAND role, the tracker orientation appears to be different with respect to all the other roles.

Tracker roles	Orientation

⚠️ The orientation around the y axis (in green) depends on the Room setup and according to the relative yaw angle between the headset and the trackers. In the pictures above, the headset was "looking" at the trackers.

In the images above, the trackers were positioned as follows: