Troubleshooting the Varjo gaze module
No gaze data at all
Cause. The module logs the Varjo runtime’s gaze tracking status on every session start:
NotAllowed (gaze tracking disabled system-wide), NoHMD (headset not connected),
Calibrating, Calibrated, or NotCalibrated. Only Calibrated produces gaze frames; the
other states are normal conditions, not failures, and produce no frame at all rather than one
with placeholder values.
Fix. Check the logged status before assuming a fault. NotCalibrated with CalibrationType
set to None will never resolve itself - either set CalibrationType to Fast or OneDot, or
run calibration through Varjo’s own tools outside HEAT Capture.
Video never appears despite EnableVideoCapture being on
Cause. Video capture requires an active Varjo Pro licence. Neither this module nor its bridge checks for that licence in code - see Overview - so there is no specific error message to look for if it is missing.
Fix. Confirm the workstation has an active Varjo Pro licence through Varjo’s own tools, not through anything in HEAT Capture.
Video has visible glitches or missing segments
Cause. The bridge’s internal queue overflowed - this module was not draining it fast enough,
so the bridge dropped the oldest queued frame(s) and forced a fresh keyframe on the affected eye.
This is most likely if Interval has been raised well above its default. See
Configure.
Fix. Lower Interval back toward its default (8 ms). If it is already at or near default
and this still happens, the workstation is likely too loaded to keep up with encoding two H264
streams at native cadence - investigate CPU/GPU load, not this setting.
The log shows repeated “Failed to parse Varjo SimulationFrame”
Cause. One frame from the bridge’s queue did not parse as a SimulationFrame - truncated or
corrupted. This module skips only that one frame and keeps draining the rest of the queue; it
does not stop capturing.
Fix. Occasional isolated occurrences are not necessarily a problem, given the note above. A high, sustained rate points at a mismatch between this module’s version and the bridge DLLs bundled with it, or a genuinely unstable bridge session - restart the capture session first.