Comparison of Spatial Visualization Techniques for Radiation in Augmented Reality

TL;DR

This work demonstrates a GPU-based method to visualize multiple radiation sources on the spatial awareness mesh of a HoloLens 2 for AR safety training. It uses stencils and orientation to present directions while accumulating dose from several virtual sources in real time, aiming to balance visibility of the real world with informative radiation cues. A 25-participant study found no visualization that significantly outperformed the others, highlighting strong individual differences and the need for tailored evaluation methods. The study provides design guidelines, discusses limitations, and outlines directions for future situated-visualization research in AR for CBRN training.

Abstract

Augmented Reality (AR) provides a safe and low-cost option for hazardous safety training that allows for the visualization of aspects that may be invisible, such as radiation. Effectively visually communicating such threats in the environment around the user is not straightforward. This work describes visually encoding radiation using the spatial awareness mesh of an AR Head Mounted Display. We leverage the AR device's GPUs to develop a real time solution that accumulates multiple dynamic sources and uses stencils to prevent an environment being over saturated with a visualization, as well as supporting the encoding of direction explicitly in the visualization. We perform a user study (25 participants) of different visualizations and obtain user feedback. Results show that there are complex interactions and while no visual representation was statistically superior or inferior, user opinions vary widely. We also discuss the evaluation approaches and provide recommendations.

Figures (9)

• Figure 1: The color palettes sampled by the fragment shaders, the continuous on the top and the 8-color banded variant on the bottom. The yellow end of the scale indicates the highest radiation levels.
• Figure 2: The actual textures used for rendering each stencil, but transparency has been colored black. The patterns were tiled differently so the hexagons appeared visually similar in scale to the circles when rendered.
• Figure 3: Illustrative examples of the visualizations on a flat plane, showing radiation from 3 sources.
• Figure 4: The layout of the experiment room.
• Figure 5: The table containing cards as used in the experiment.