View Splicing for Effective VR Collaboration

In a co-located multi-user collaborative virtual reality (VR) application a collaborator should be able to indicate a workspace location to the user, such that they can refer to it simultaneously as they work together. Due to their different viewpoints, the collaborator sees some parts of the virtual environment (VE) that the user does not, and communication breaks down when the collaborator's reference is not visible to the user. The conventional solutions of asking the user to move around to gain line of sight to the collaborator's reference, or of asking the user to toggle back and forth between their view and that of the collaborator can be inefficient and ineffective. This paper proposes a method for improving collaboration in VR by alleviating the disparity between the user and the collaborator views of the VE. The user is shown a multiperspective visualization of the VE that transitions smoothly from the user to the collaborator's perspective. The multiperpsective visualization is based on the switch camera, a novel camera model with curved rays that splice together the user and collaborator views. The multiperspective visualization is computed first by warping the VE geometry, through projection with the switch camera followed by unprojection with a conventional camera, and then by rendering the warped VE conventionally, for each user eye. A controlled user study with three tasks shows that VR collaboration using the switch camera multiperpsective visualization is faster, more reliable, and less taxing on the user than the conventional approaches of viewpoint translation or view toggling.