Motion planning for camera movements

Moving a camera through a (virtual or real) environment is a complicated task. Often a user is given direct control of the camera. Such direct control is difficult for inexperienced users and results in rather ugly camera motions that easily lead to motion sickness. In this paper we describe a new technique for automatic generation of camera motion using motion planning techniques from robotics. We focus here on motion in virtual environments. In our approach the user simply specifies a required goal position (and orientation) using e.g. a map, and the system automatically computes a smooth, collision free motion from the current position and orientation to the required position (and orientation) that can be used by the camera. As preprocessing, the approach uses the probabilistic roadmap method to compute a roadmap through the environment. When a motion is required, a path is obtained from the roadmap which is then improved by various smoothing techniques to satisfy constraints from cinematography.

I. Introduction

In many virtual environment applications, like games, architectural walkthroughs, urban planning systems, CAD model inspection systems, and training systems, the user must navigate through the environment to inspect it and perform certain tasks. Navigation means: steering a camera through the environment. In most of today's systems this is done using a joystick or arrow keys. on the keyboard in combination with a mouse. Such direct control has a number of disadvantages. It is difficult for inexperienced users, it results in rather ugly motions that easily lead to motion sickness, and it requires a lot of attention while the user should preferably concentrate on more higher-level tasks at hand.