Christoph Albert Johns

arXiv2026

Heads Up!: Towards In Situ Photogrammetry Annotations and Augmented Reality Visualizations for Guided Backcountry Skiing

Backcountry skiing is an activity where a group of skiers navigate challenging environmental conditions to ski outside of managed areas. This activity requires careful monitoring and effective communication around the current weather and terrain conditions to ensure skier safety. We aim to support and facilitate this communication by providing backcountry guides with a set of in situ spatial annotation tools to communicate hazards and appropriate speeds to the ski recreationalists. A guide can use a tablet application to annotate a photogrammetry-based map of a mountainside, for example, one collected using a commercial camera drone, with hazard points, slow-down zones, and safe zones. These annotations are communicated to the skiers via visual overlays in augmented reality heads-up displays. We present a prototype consisting of a web application and a virtual reality display that mirror the guide's and skier's perspectives, enabling participatory interaction design studies in a safe environment.

cs.HC↗

arXiv2023

Mixed Reality UI Adaptations with Inaccurate and Incomplete Objectives

This position paper outlines a new approach to adapting 3D user interface (UI) layouts given the complex nature of end-user preferences. Current optimization techniques, which mainly rely on weighted sum methods, can be inflexible and result in unsatisfactory adaptations. We propose using multi-objective optimization and interactive preference elicitation to provide semi-automated, flexible, and effective adaptations of 3D UIs. Our approach is demonstrated using an example of single-element 3D layout adaptation with ergonomic objectives. Future work is needed to address questions around the presentation and selection of optimal solutions, the impact on cognitive load, and the integration of preference learning. We conclude that, to make adaptive 3D UIs truly effective, we must acknowledge the limitations of our optimization objectives and techniques and emphasize the importance of user control.

cs.HC↗