RESEARCH

RE-USE OF FACIAL ANIMATION RIGGINGS

Researches: Verónica Costa-Teixeira Orvahlo, Antonio Susin

Description:
Facial animation is related to the interaction of muscles and skeletons beneath the skin. It is the key element to transmit individuality and personality to a character in films and video games. Therefore, to obtain physically-based animations, it is crucial to develop systems that simulate the anatomical structure of the face.

Fig 1.

Recent advances in facial synthesis show an increased interest in physics-based approaches [WF95] [YSK02] [SL96]. Today, to animate a character, an experienced CG artist has to model each facial rig by hand, making it impossible to reuse the same rig in different facial models. The task is further complicated when a minor artistic change on the facial topology leads to the restarting of the rigging process from scratch.  This creates a bottleneck in any CG production and leads to the research of automated methods to accelerate the process [JTD03]. Modeling and animation of deformable objects have been applied to different fields [ACW04] [BK04]. Noh et al. [NN01] proposed several methods for transferring animations between different face models. The surface correspondence is obtained by specifying the corresponding point pairs on the models. Pighin et al. [SSP98] presented a method to interactively mark corresponding facial features in several photographs of an individual, to deform a generic face model using radial basis function. Sederberg and Parry [SP86] first introduced Free-Form Deformation (FFD) in 1986; the method does not require setting the corresponding features on the geometries. Other interesting approaches for high level geometric control and deformation over 3D model were introduced [Co90] [HHK92] [SF98].

Fig 2.  Landmarks and internal structure for the source model.

We have obtained a deformation method to transfer the inner structure of a generic rig to individual face models, based on thin-plate splines [Bo89] and the use of facial features labels. We will tag the generic rig with landmarks on its surface (the skin) and automatically deform it, together with the muscle and skeleton structure, to fit different face models. Therefore, all models will share the same generic set of attributes, and we will don't need to develop unique scripts for each face. We can transfer generic rig parameters, enabling re-use of existing animation scripts.

Fig 3. Transfer of shapes from the source model

We can build models with underlying anatomical structure, skin, muscle and skeleton, for human heads or other type of creatures. The models will be suitable for real-time animation based on simulation of facial anatomy.

Publications:

Costa-Teixeira V., Susin A.
Transferring the Rig and Animations from a Character to Different Face Models.
Computer Graphics Forum, Submitted, 2007.

Costa-Teixeira V., Zacur E., Susin A.
A MAYA Plug-in for Transferring a Labeled Generic Rig to Animate Face Models. International Digital Games Conference (iDiG'06). Editors Dionisio J., Ramires Fernades A. Proc. iDiG-06, pp 12-20 (2006).

Costa-Teixeira V., Zacur E., Susin A.
Transferring a Labeled Rig to Animate Face Models.
IV Conference on Articulated Motion and Deformable Objects (AMDO-06). Editors Perales F. Fisher B. Proc. AMDO-06, Ed. Springer Lecture Notes, pp 21-31 (2006).

Costa-Teixeira V., Zacur E., Susin A.Transferring Facial Expressions to Different Face Models. 3th Ibero-American Symposium in Computer Graphics (SIACG-2006). Editors Brunet P., Correia N., Baranoski G. Proc. SIACG-06, pp 21-28 (2006).

References:

[ACW04] A. Angelidis, M. Cani, G. Wyvill, and S. King, Swirling-sweepers: Constant-volume modeling, Pacific Graphics 2004, 2004.
[Bo89] F. Bookstein, Principal warps: Thin-plate splines and the decomposition of deformations, IEEE Trans. on Pattern Anaylsis and Machine Intelligence, vol. 11, no. 6, 1989, pp. 567--585.
[BK04] M. Botsch and L. Kobbelt, An intuitive framework for real-time freeform modeling, ACM Transactions on Graphics, SIGGRAPH '04, 2004, pp. 23(3), 630--634.
[Co90] S. Coquillart, Extended free-form deformations: A sculpturing tool for 3d geometric modeling, Proc. SIGGRAPH 90' Conf., ACM Computer Graphics, 1990, pp. 187--196.
[CZS06] Costa-Teixeira V., Zacur E., Susin A. Transferring Facial Expressions to Different Face Models.  In Proc. 3th Ibero-American Symposium in Computer Graphics (SIACG-2006)
Brunet P., Correia N., Baranoski G Ed,  pp 21—28 (2006).
[HHK92] W.M. Hsu, J.F. Hugues, and H. Kaufman, Direct manipulation of freeform deformation, Proc. SIGGRAPH '92, ACM Press, 1992, pp. 177--184.
[JTD03] P. Joshi, W. Tien, M. Desbrun, and F. Pighin, Learning controls for blend shape based realistic facial animation, Eurographics/SIGGRAPH Symposium on Computer Animation, ACM Press, 2003, pp. 187--192.
[NN01] J. Noh and U. Neumann, Expression cloning, Proc. SIGGRAPH '01 Conf, ACM SIGGRAPH, 2001, pp. 277--288.
[SP86] T. Sederberg and S. Parry, Free-form deformation of solid geometric models, Proc. SIGGRAPH 86' Conf., ACM Computer Graphics, 1986, pp. 151--160.
[SF98] K. Singh and E. L. Fiume, Wires: a geometric deformation technique, Proc. SIGGRAPH 98' Conf., ACM Computer Graphics, 1998, pp. 405--414.
[SL96] R. Szeliski and S. Lavallee, Matching 3d anatomical surfaces with nonrigid deformation using octree splines, Internatinal Journal of Computer Vision 18,2, 1996, pp. 171--186.
[SSP98] R. Szeliski D.H. Salesin F. Pighin, D. Lischinski and J.Hecker, Synthesizing realistic facial expressions from photographs, Proc. SIGGRAPH'98 Conf, 1998, pp. 75--84.
[WF95] K. Waters and J. Frisbie, A coordinated muscle model for speech animation, Proc. Graphics Interface '95, 1995, pp. 163--170.
[YSK02] H. Yamauchi H. Seidel K. Kahler, J. Haber, Head shop: Generating animated head models with anatomical structure, ACM, 2002.