Designing and comparing two-handed gestures to confirm links between user controlled objects

Systems using two-handed spatial manipulation techniques also require strategies to enable system control tasks. These strategies make it possible to interact with the system comfortably while controlling two hand-held objects simultaneously. The Augmented Chemical Reactions project makes intense use of such two-handed interaction tasks. Users control virtual molecules and subsets that are registered to physical markers and try to combine those by selecting and then confirming a specific bond. When a desired bond has been selected, the user needs a way to confirm that bond without letting an atom go out of position. We developed and investigated two separate methods of confirming a selected bond when both hands are already doing a two-handed symmetric interaction task. The first method is a waiting method and the second method is a back&forth motion gesture. We evaluated the two methods in a user study, showing that the first technique, holding still, outperforms the other technique.