openvr_ros_bridge

Publishes poses from HMD/controllers/anything trackable from OpenVR on Windows to ROS. It can also publish JSON to a generic websocket target, or log poses to a file.

Prerequisites

• Windows: 64 bit windows and directx 11 support (e.g., a VR capable machine)
• Linux: 64 bit Linux with real graphics drivers (NOT MESA)
• [optional] ROS: the rosbridge suite

Installation

Windows: download the binary release and unzip somewhere convenient.

Linux: download the binary release. Then compile the renderimprovements branch of truss.

E.g.,

git clone --single-branch -b renderimprovements https://github.com/PyryM/truss 
mkdir build
cd build
cmake ..
make

Then from dist/ copy the truss binary truss and the libs/ folder (hopefully populated with .so files) into the directory where you extracted openvr_ros_bridge.

Usage

General / File logging

SteamVR should be started before the bridge, otherwise the bridge will itself try to start SteamVR, which is unreliable and may lead to a freeze or a crash.

truss url_or_filename config_script_name.t

For example, the config script config/default.t will log to a text file in csv format. To log to "my_log.txt", run

truss my_log.txt default.t

Running without an HMD

It is possible to run without the HMD connected, if you have Vive trackers, or if you have paired the controllers to a Bluetooth adaptor (normally the controllers pair to the built-in Bluetooth of the HMD, which is why it must be plugged in).

The steamvr.vrsettings file must be edited so that

"requireHmd": false,

AMD Ryzen note

If you have an AMD Ryzen or other exotic CPU, you will probably need to edit scripts/core/core.t within truss.zip and change line 8 to:

local use_ryzen_hack = true

Linux notes

If you see the message Going to create window; if you get an LLVM crash on linux at this point, the mostly likely reason is that you are using the mesa software renderer. and then truss crashes, then you are probably using Mesa drivers. The solution is to install real drivers. You can also try to disable Mesa/llvmpipe by setting the DRAW_USE_LLVM environment variable to 0.

SteamVR has special requirements to run on Linux: see the SteamVR Linux readme. In particular, you will need to invoke truss like

~/.steam/steam/ubuntu12_32/steam-runtime/run.sh ./truss [bridge options]

ROS

On a machine with ROS:

1. Start a roscore
2. Launch the ros web bridge: roslaunch rosbridge_server rosbridge_websocket.launch

On the VR machine (can be the same as the ROS machine):

1. Start SteamVR (optional, but greatly speeds up startup)
2. In a command prompt/terminal, navigate to the openvr_ros_bridge folder
3. In prompt run: truss "ws://[host]:[port]" ros.t. Note that the default rosbridge port is 9090, so this will look something like truss "ws://othercomp:9090" ros.t. (For Linux, see the note above regarding running with the Steam runtime).

Configuration

Config scripts should be placed in scripts/config/. The file scripts/config/default.t contains the default configuration that will log poses to a file in CSV format. By default only controllers and generic trackables are logged.

File logging configuration

local publishers = require("file_publishers.t")
local config = {}
config.Connection = publishers.FileConnection
config.Controller = {
  topic = "controller_%d",
  publisher = publishers.Pose,
  display = true
}
return config

The file Pose publisher accepts the following additional options

Option	Description	Default
decimate	Publish only 1 in n frames	9
field_order	Ordered list of fields to write to CSV	{"time", "position", "quaternion"}
divider	Field divider	","
precision	Numerical precision to write	4
format	Numerical format string (overrides precision)	"%.4f"

ROS publishing configuration

local publishers = require("ros_publishers.t")
local config = {}
config.Connection = publishers.ROSConnection
config.Controller = {
  topic = "/vr/controller_%d",
  publisher = publishers.Pose,
  display = true
}
return config

The ROS Pose publisher accepts the following additional options

Option	Description	Default
decimate	Publish only 1 in n frames	9
tf_frame	ROS TF frame to associate PoseStamped messages with	"0"
queue_size	Maximum ROS queue size	10

Visualization configuration

Visualization options are independent of publishing/logging, and are specified in the display options in a configuration. Setting display = true uses the default visualization option, which is to just show the model. Likewise, display = false will not display anything (but will still publish if publication options are set).

Additional visualization options can be included by setting display.

local vis = require("visualizers.t")

config.Controller = {
  -- [...]
  display = {vis.BasicModel(), vis.LineHistory()} -- show model and trails
}

Note the slightly unconventional syntax of having to actually call/construct the visualizer options, which is to allow additional options to be passed to a specific visualizer.

LineHistory

Adds a trail to a trackable.

vis.LineHistory({
  history_length = 900,    -- how many points the line can have
  decimate = 3,            -- only push a new point every n frames
  color = {0.8, 0.3, 0.3}, -- line color, in [0,1] RGB format
  thickness = 0.005        -- line thickness, in m
})

BasicModel

Shows a mesh model for the trackable, loaded from OpenVR.

vis.BasicModel({
  diffuse = {0.03,0.03,0.03,1.0},   -- diffuse color
  specular = {0.001, 0.001, 0.001}, -- specular color
  roughness = 0.7                   -- roughness
})