DEMoCap can be used with Meta Quest HMDs to do limited motion capture. With these HMDs only upper body motion capture are usable with the following features present (depending on your Quest model):

• Head tracking
• Hand tracking (controller or hands only)
• Eye tracking
• Face tracking
• Finger tracking

Right now DEMoCap does not yet run on the Quest itself. Instead you have to connect the Quest to your PC where DEMoCap runs. This connection can be either wired or wireless using one of these programs:

• WiVRn: Wired and wireless for Linux.
• SteamLink: Wireless for Windows and Linux.
• ALVR: Wireless for Windows.
• Occulus Link/AirLink: Wired and wireless for Windows.

The most stable out of these is WiVRn. There controller and hands only works good. SteamLink has problems with finger tracking breaking the capture on Linux. Occulus Link/AirLink pretty much can't do finger tracking at all. Hence with controller mode various solutions are working while with finger tracking WiVRn seems to be the most reliable one. You have to try for yourself what works for your setup.

The Quest 3 (3S) supports estimated full body tracking. For this the Quest uses the cameras built into the HMD to estimate the full body pose using AI calculations running on the headset. These poses can be retrieved as either a skeleton or as simulated trackers using WiVRn. DEMoCap supports simulated trackers using WiVRn. Unfortunately this has some problems since the way WiVRn simulates the trackers is unfavorable for DEMoCap. This section outlines how to best configure DEMoCap and your characters to get the most out of a Quest FBT setup.

Since the Quest produces a simulated full body the actor proportions are not matching those of the actor as outlined in Create Actor. While you can use your own body proportions the results are most likely off. Hence if you plan to use Quest FBT it is recommended to create a custom actor profile named “Quest FBT” or similar. This you can then use instead of your actor profile when working with Quest FBT.

Since the quest only can use reliably the floor distance of the headset it calculates the body proportions solely from it. In general the floor height of a Quest is your own height minus 8-10cm. Hence you can measure your own height and then fill in the values as follows:

• Shoulder Level: Height - 0.4
• Shoulder Width: (Height - 0.09) * 0.25
• Arm Length: (Height - 0.09) * 0.45
• Leg Length: (Height - 0.09) * 0.475
• Foot Distance: Same as Shoulder Width

For example if you measure your height as 1.8m then you would enter the following values:

• Shoulder Level: 1.4
• Shoulder Width: 0.4275 (or rounded 0.42)
• Arm Length: 0.7695 (or rounded 0.77)
• Leg Length: 0.81225 (or rounded 0.81)
• Foot Distance: Same as Shoulder Width

As mentioned above the simulated WiVRn trackers of unfavorable. In particular the elbow tracker is located at the elbow but with the orientation of the lower arm instead the orientation of the upper arm. If you use these simulated trackers directly you will get bad poses, for example the elbow spread depending on your lower arm bending instead of your upper arm position.

You can counter this problem the following way:

• Create a duplicate of your character configuration you usually use
• Select the AutoHuman Motion Transfer
• In the Advanced panel tick the Elbow guide use position checkbox
• Save profile

The Elbow guide use position tells DEMoCap to use the position of the elbow trackers to guide the inverse kinematics instead of using the orientation. This solves the problem of the simulated tracker orientation to be wrong but the quality degrades the further away your pose gets from the base IK pose. How well this extreme poses work depends on the character skeleton and the base IK animation used.