PyEtSimul: An Open-Source Python Framework for Eye-Tracking Simulation ETRA009

This paper presents PyEtSimul, an open-source Python-based framework for simulating video-based eye trackers by generating synthetic eye features through geometric modeling. The framework allows flexible positioning of eyes, cameras, and light sources in 3D space, with controlled variation of eye anatomical features and camera properties. PyEtSimul generalizes corneal modeling by representing the cornea as a conic surface rather than the common sphere. It also supports non-circular pupil shapes, size-dependent pupil decentration, eyelid occlusion, and camera lens distortion. It supports systematic data generation and principled comparison of gaze estimation algorithms across calibrated and uncalibrated settings. These features enable analyses not possible with other available simulators. PyEtSimul facilitates controlled experiments with known parameters often latent in normal settings, enabling reproducible benchmarking and systematic exploration of hardware designs. By generating fully synthetic data, PyEtSimul removes privacy concerns and the need for costly hardware, making it practical for both educational and research applications.