Calculate gaze points from gaze ray

[SHU WEI]

Hello team,

I would like your help in interpreting the gaze ray data and the standard procedure to calculate gaze points from the gaze ray.

I’ve gone through the official doc and relevant Q&A in this forum, so seems the gaze ray (origin and direction) is a normalized direction vector, and we need to use ‘gaze.origin + gaze.direction * length’ to calculate gaze points coordinates? I wonder where I can get the ‘length’ data (presume it’s ‘ConvergenceDistance’)?

Also, I have access to both the core and Ocumen API, and I wonder what’s the difference between the GazeRay from “TobiiXR_EyeTrackingData” and “TobiiXRAdvanced.LatestData”? While the TobiiXR_GazeRay objects have the same definition on your website, I got different values. Is this because the advanced API provides the latest data, and the core API gaze ray has a delay? In this case, should I use the gaze ray from Advanced API rather than the core one? (see below comparison, both gazeRay data are valid)
Core: origin(-0.3, 1.5, 0.0) direction(0.0, 0.2, -1.0)
Advanced: origin(0.0, 0.0, 0.0) direction(0.3, 0.1, 0.9)

Best,
Shu

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