Automatic expressive deformations for stylizing motion

3D computer animation often struggles to compete with the flexibility and expressiveness commonly found in traditional animation, particularly when rendered non-photorealistically. We present an animation tool that takes skeleton-driven 3D computer animations and generates expressive deformations to the character geometry. The technique is based upon the cartooning and animation concepts of 'lines of action' and 'lines of motion' and automatically infuses computer animations with some of the expressiveness displayed by traditional animation. Motion and pose-based expressive deformations are generated from the motion data and the character geometry is warped along each limb's individual line of motion. The effect of this subtle, yet significant, warping is twofold: geometric inter-frame consistency is increased which helps create visually smoother animated sequences, and the warped geometry provides a novel solution to the problem of implied motion in non-photorealistic still images.

[1]  F. Thomas,et al.  Disney Animation: The Illusion of Life , 1981 .

[2]  Michael Cohen,et al.  The cartoon animation filter , 2006, SIGGRAPH 2006.

[3]  Kunio Kondo,et al.  Cartoon Blur: Non-Photorealistic Motion Blur. , 2003 .

[4]  Wen Tang,et al.  Modelling and animating cartoon hair with NURBS surfaces , 2004, Proceedings Computer Graphics International, 2004..

[5]  Stan Lee,et al.  How to Draw Comics the Marvel Way , 1978 .

[6]  Christopher Hart.  Everything You Ever Wanted to Know About Cartooning But Were Afraid to Draw , 1994 .

[7]  Siu Chi Hsu,et al.  Drawing and animation using skeletal strokes , 1994, SIGGRAPH.

[8]  Marcin Szymanski,et al.  Simulating cartoon style animation , 2002, NPAR '02.

[9]  Thomas W. Sederberg,et al.  Free-form deformation of solid geometric models , 1986, SIGGRAPH.

[10]  Richard Williams,et al.  The Animator's Survival Kit , 2001 .

[11]  John Lasseter,et al.  Principles of traditional animation applied to 3D computer animation , 1987, SIGGRAPH.

[12]  T. White.  The Animator's Workbook , 1986 .

[13]  Maneesh Agrawala,et al.  The cartoon animation filter , 2006, ACM Trans. Graph..

[14]  Kenneth I. Joy,et al.  Free-form deformations with lattices of arbitrary topology , 1996, SIGGRAPH.

[15]  Paul Rademacher,et al.  View-dependent geometry , 1999, SIGGRAPH.

[16]  Stefan Schlechtweg,et al.  Non-photorealistic computer graphics: modeling, rendering, and animation , 2002 .

[17]  David R. Forsey,et al.  How to Render Frames and Influence People , 1994, Comput. Graph. Forum.

[18]  Mark J. Harris,et al.  Stylized rendering techniques for scalable real-time 3D animation , 2000, NPAR '00.

[19]  Wen Tang,et al.  Modelling and animating cartoon hair with NURBS surfaces , 2004 .

[20]  Michael Potmesil,et al.  Modeling motion blur in computer-generated images , 1983, SIGGRAPH.

[21]  Harry Shum,et al.  Stylizing motion with drawings , 2003, SCA '03.

[22]  Christoph Bregler,et al.  Turning to the masters: motion capturing cartoons , 2002, ACM Trans. Graph..