Interactive Scene Walkthrough Using a Physically-Based Virtual Camera
Russell Turner, Jean‐Francis Balaguer, Enrico Gobbetti, Daniël Thalmann · 1991
One of the most powerful results of recent advances in graphics hardware is the ability of a computer user to interactively explore a virtual building or landscape. The newest threedimensional input devices, together with high speed 3D graphics workstations, make it possible to view and move through a 3D scene by interactively controlling the motion of a virtual camera. In this paper, we describe how natural and intuitive control of building walkthrough can be achieved by using a physically-based model of the virtual camera's behaviour. Using the laws of classical mechanics to create an abstract physical model of the camera, we then simulate the virtual camera motion in real time in response toforce data from the various 3D input devices (e.g. the Spaceball and Polhemus 3Space Digitizer). The resulting interactive behaviour of the model is determined by several physical parameters such as mass, moment of inertia, and various friction coefficients which can all be varied interactively, and by constraints on the camera's degrees of freedom. This allows us to explore a continuous range of physically-based metaphors for controlling the camera motion. We present the results of experiments using several of these metaphors for virtual camera motion and describe the effects of the various physical parameters.