Terrain Modelling with a Pen & Touch Tablet and Mid-Air Gestures in Virtual Reality

World building or terrain modelling is an essential task when designing games, natural simulations or artistic creations involving virtual 3D landscapes. To support this task, we propose a virtual reality (VR) system based on a pen and touch tablet used in a sitting position (desktop VR) such that both hands are free to interact in an asymmetric way (pen hand + other bare hand). We present and compare several techniques to perform navigation, sculpting and menu operations using the two hands, which interact on and above the tablet surface, i.e. using the pen, touch and mid-air input spaces. A qualitative evaluation with 16 participants confirms the entertaining nature and practical benefits of our system. The study further underlines the complementarity of the different modalities and identifies the promising—and as of yet underexplored—combination of bimanual touch + pen + mid-air interaction in desktop VR.