Geometry Simplification Methods for Virtual Reality Applications

Virtual Reality (VR) applications play an important role in HEP Outreach & Education. They enable the organization of virtual tours of the experimental infrastructure by allowing users to interact virtually with detector facilities and describe their purpose and functionalities. However, nowadays, VR applications require expensive hardware, like the Oculus headset or the MS HoloLens, and powerful computers. As a result, this reduces the reach of VR application implementation and makes their benefits questionable. An important improvement to VR development is thus to facilitate the usage of inexpensive hardware, like Google cardboard and phones with average computational power. Requirements to use inexpensive hardware and achieve quality and performance close to the advanced hardware bring challenges to VR application developers. One of these challenges concerns the geometry of the 3D VR scenes. Geometry defines the quality of the 3D scenes and at the same time, causes big loads on the GPU. Therefore, development methods of the geometry make it possible to find a good balance between the quality and performance of the VR applications. This paper describes methods for simplifying the “as-built” geometry of the ATLAS detector, ways to reduce the number of facets to meet GPU performance limitations, and ensure smooth movement in VR scenes.