3D animation creation using space canvases for free-hand drawing

In this paper we present a novel 3D animation system using a set of easily manipulable space canvases that support free-hand drawing. Our aim is to support the traditional free-hand drawing while improving the functionality by imitating the 3D animation in terms of free-viewing and free animation. The system design emphasis is on the feeling of "what you see is what you get". In our system a user is allowed to create planar and curved canvases and place them in 3D space with six degrees of freedom. Free-hand strokes are drawn on each canvas by using any of a user's favorite input device; a mouse, a digital pen, etc. Various canvases organized in space form a scene and the animation key frames of those canvases and strokes can be recorded hierarchically to represent different levels of movement in the scene. The camera's movement is recorded when a user tunes the viewing parameters and chooses to add a key frame in the time line for the camera. The system is both intuitive by utilizing the advantage of 2D freehand drawing and has the capability of 3D manipulation of strokes, canvases and a camera without requiring the user to have knowledge of 3D graphics and animation. We demonstrate the usability and efficiency of our system by describing the creation process of several short animation movies.