Figure 1: From left to right: the user on the platform wearing an HMD and holding the pointing device; a ray cast for coarse selection; a highlight of the fine selection by pinching on the handheld screen; a resulting labelled model. ABSTRACTThis paper presents a 3D user interface to select and label point sets in a point cloud. A walk-in-place strategy based on a weight platform is used for navigation. Selection is made in two levels of precision. First, a pointing technique is used relying on a smartphone and built-in sensors. Then, an ellipsoidal selection volume is deformed by pinching on the smartphone touchscreen in different orientations. Labels are finally selected by pointing icons and a hierarchy of labels is automatically defined by multiple labeling. Voice is used to create new icons/labels. The paper describes the concepts in our approach and the system implementation.