HTC Vive Trackers

Vive Trackers are an extension for the SteamVR support which makes it possible to tracks body parts like head, arms, hips and feet by attaching them to the various body parts.

Prerequisites

InstantVR

Vive Trackers are not supported in InstantVR

Humanoid Control

Vive Trackers are supported in the Humanoid VR+ and Pro packages and can be obtained as a separate extension for Humanoid VR.

Hardware

HTC Vive Trackers require the HTC Vive headset connected to the same system.

Operating System

Vive Trackers are supported on the Microsoft Windows platform.

Setup

For HTC Vive Tracker support, both SteamVR Support and Vive Tracker Support need to be enabled in the Humanoid Preferences. You can find these in theĀ Edit Menu->Preferences->Humanoid.

pre Unity 2017.2: Virtual Reality Supported needs to be enabled in Edit Menu->Project Settings->Player->Other Settings. OpenVR needs to be added to the Virtual Reality SDKs.

Unity 2017.2 and higher: Virtual Reality Supported needs to be enabled in Edit Menu->Project Settings->Player->XR Settings. OpenVR needs to be added to the Virtual Reality SDKs.

 

 

 

Targets

The location of Vive Trackers on the body is recognized automatically, so there is not need to register tracker IDs. The conditions for detection are listen below for each target.

When not all trackers have been identified yet, it is possible that they change location on the body. For example when a tracker is first recognized as a hip tracker and later moves above 1.2m and no head tracker has been detected yet, it will transform into a head tracker.

Trackers are only recognized being on a certain body part if the Vive Tracker has been enabled for that body part. So if Vive Trackers are not enabled on the feet, no Vive Tracker will be recognized as a foot tracker.

The tracker assignment process is restarted when Calibrate() is called on the Humanoid Control component.

Head Target

A Vive Tracker can be used on the head instead of an HMD. There is no need to have a First Person Camera or any camera at all in the scene.

It is not possible to have both a HMD (First Person Camera) and Vive Tracker on the head.

A head mounted Vive Tracker is recognized automatically when an active tracker is detected at least 1.2m above ground level.

Hand Target

Vive Trackers can be placed on different bones on the arm. This makes it possible to combine a SteamVR controller with a Vive Tracker on the arm to improve the Inverse Kinematics solution. The bone on which the tracker in mounted should be set using the Bone parameter.

It is not possible to have both a SteamVR controller and a Vive Tracker on the hand.

Trackers on the arm are recognized at the left and rightmost tracker.

Left and right are relative to the forward direction of the headset. So even if the HMD is not used, it still needs to be place such that it is pointing in the forward direction at start.

Hips Target

A Vive Tracker can be placed on the hips. In this position the orientation of the tracker is not used, so it is not important how the tracker is rotated around the Vive logo (forward direction).

A Tracker on the hips is recognized when an active tracker is found between 0.3m and 1m above ground level.

Foot Target

Vive Trackers on the foot are recognized when they are less than 0.2m above ground level. The left foot tracker is the leftmost tracker below 0.2m, the right foot tracker the rightmost tracker below 0.2m.

Left and right are relative to the forward direction of the headset. So even if the HMD is not used, it still needs to be place such that it is pointing in the forward direction at start.