How does one unify forward facing direction on multiple VR devices?

Target Platforms XR
,
1

I’m working on a cross platform VR game and have run into an issue where each HMD apparently has a different forward facing direction. I’m testing this with a simple scene that just has a cube placed on the +Z axis. The camera rig is centered with no rotation and no offsets in the parent transforms.

When I run it on Quest 2 the cube is directly ahead as it should be, but when I run it on Quest 1 the cube is behind me (180 degrees). And on Vive it is directly to the left (90 degrees).

With each device I make sure that the HMD is facing forward and recentered when launched. Also, in my app code I am calling XRInputSubsystem.TryRecenter, but it makes no difference with or without it. Recentering in the device also makes no difference.

I should also mention that I’m using Unity 2022.3.5 with the latest XR Interaction Toolkit 2.4.3.

Is there a way the forward direction can be unified for all HMDs?

2

My workaround for now is the following method in my camera controller script. Since the XR system translates the camera directly, I am simply looking at it’s orientation upon starting each scene and rotating the rig accordingly.

private void Recenter()
{
    if (IsXR) {
        XRUtil.Recenter();
        Vector3 orient = Vector3.zero;
        Vector3 euler = XRCamera.transform.eulerAngles;
        if (euler.y < -135f) {
            orient.y = 180f;
        }
        else
        if (euler.y > 135f) {
            orient.y = 180f;
        }
        else
        if (euler.y < -45f) {
            orient.y = 90f;
        }
        else
        if (euler.y > 45f) {
            orient.y = -90f;
        }
        XRCameraRig.transform.eulerAngles = orient;
    }
}

Open to any suggestions if there is a better way to handle it.