RIST: Radiological Immersive Survey Training for two simultaneous users

National Guard Civil Support Teams (CST) respond to a variety of situations involving dangerous materials. Many of these situations can be safely simulated for training purposes in the real world. Radiological threats, however, are difficult to simulate due to the lack of materials that can mimic radiation sources without the danger of the real radiation. To address the need for a system to train CSTs to respond to radiological threats, we have developed the Radiological Immersive Survey Training (RIST) system. RIST simulates radiological threats from multiple sources using a realistic real-time shielding model based on ray casting and allows users to practice surveying the threat using simulated representations of the world and equipment. We have developed an after action review tool to allow a trainer to show trainees a recording of their survey and how they can improve. We also created a scenario design tool to allow the trainer to create complex environments with radiological threats. We developed novel multi-user interaction techniques to enable simultaneous training for two CST members in an immersive virtual environment. We also introduced a novel multi-perspective rendering technique for two users based on each user's task rather than field of view. Finally, we conducted a preliminary user study with several pairs of expert users to measure user preferences and the effects of using this technique, in conjunction with how altering which user navigated, on user performance. CST survey teams from two states have now used the system for training.