GazeEnViz4D: 4-D Gaze-in-Environment Visualization Pipeline

Eye-tracking data visualization and analysis is often performed in three dimensions (x,y,t). It involves overlaying the gaze point (x,y) on scene-camera images and creating a pipeline to process the gaze-overlaid spatio-temporal data. In this project, we present a pipeline (called GazeEnViz4D) to extract 3D data from raw 2D eye-tracking data, and we have developed a custom ENvironment VIsualiZer (EnViz4D) to allow researchers to visualize the pipeline-processed data in four dimensions (x,y,z,t) for extensive, interactive analysis. GazeEnViz4D consists of creating a 3D point cloud of the environment, calculating the observer motion, locating the 2D gaze obtained from the eye-tracker in the 3D model, and visualizing the data over time using EnViz4D. EnViz4D allows a researcher to zoom in the environment at any instance, pause or play the 3D data, speed up or slow down, forward or reverse, essentially recreating the data collection episode in four dimensions from an arbitrary modifiable viewpoint. (C) 2021 The Authors. Published by Elsevier B.V.