Imagine Internships

(2011-2012)

Advisors

Rémi Ronfard, IMAGINE team
Contact : remi.ronfard@inria.fr (04 76 61 53 03)

Consultants

Marie-Paule Cani, and Alla Sheffer (UBC Vancouver, Canada)

Context and Objectives

Creating convincing 2D animations requires specialized skills to draw the same character consistently in different poses with the right timing, and patience for interpolating between keyframes [1,2].
This internship will focus on building intermediate 2D/3D representations that can assist the artist while drawing animation. We will illustrate the process on the problem of «rotoscoping» existing movie scenes [3] into hand drawn animation, where the characters and viewpoints in the animation are different from the original video, but the "look and feel" of the animation is retained.
One inspiration for this work will be the 2.5D cartoon model [4] proposed recently as a useful tool for generating intermediate views of a cartoon model. The artist draws a character with strokes in several views and a depth value is automatically computed for each stroke in each view. In order to animate such models, it will be needed to extend them significantly with a kinematic structure (skeleton) and an underlying 3D shape explaining the deformations and occlusions of the strokes.
To ease the creation process, we will seek to recognize the structure of body parts directly from freely drawn 2D sketches, possibly using stroke colors or constellation models [5]. This will allow us to provide guide-lines during the drawing of new keyframes, and to refine the 2.5D structure while new poses from different viewpoints are drawn.
The proposed 2.5D and 3D representations will be used to interpolate the character's movement between keyframes, possibly using motion information extracted from the video, in order to produce a smooth and natural animation retaining the "look and feel" of the example video sequence, but from a different viewpoint and with different, non-realistic actors.

References

[1] James Davis, Maneesh Agrawala, Erika Chuang, Zoran Popovic and David Salesin. A Sketching Interface for Articulated Figure Animation. /SIGGRAPH Symposium on Computer Animation (2003).

[2] B. Whited, G. Noris, M. Simmons, R. Sumner, M. Gross, J. Rossignac. BetweenIT: An Interactive Tool for Tight Inbetweening. Eurographics 2010.

[3] Aseem Agarwala, Aaron Hertzmann, David Salesin, Steven Seitz. Keyframe-Based Tracking for Rotoscoping and Animation. ACM Transactions on Graphics (Proceedings of SIGGRAPH 2004), 2004.

[4] Alec Rivers, Takeo Igarashi, Frédo Durand. 2.5D Cartoon Models. SIGGRAPH 2010

[5] Dana Sharon and Michiel van de Panne. Constellation Models for Sketch Recognition. Eurographics Workshop on Sketch Based Interfaces and Modeling 2006.