ABSTRACT
Good character animation requires convincing skin deformations including subtleties and details like muscle bulges. Such effects are typically created in commercial animation packages which provide very general and powerful tools. While these systems are convenient and flexible for artists, the generality often leads to characters that are slow to compute or that require a substantial amount of memory and thus cannot be used in interactive systems. Instead, interactive systems restrict artists to a specific character deformation model which is fast and memory efficient but is notoriously difficult to author and can suffer from many deformation artifacts. This paper presents an automated framework that allows character artists to use the full complement of tools in high-end systems to create characters for interactive systems. Our method starts with an arbitrarily rigged character in an animation system. A set of examples is exported, consisting of skeleton configurations paired with the deformed geometry as static meshes. Using these examples, we fit the parameters of a deformation model that best approximates the original data yet remains fast to compute and compact in memory.
Supplemental Material
- ALLEN, B., CURLESS, B., AND POPOVIĆ, Z. 2002. Articulated body deformation from range scan data. ACM Transactions on Graphics 21, 3 (July), 612--619. Google ScholarDigital Library
- BURTNYK, N., AND WEIN, M. 1976. Interactive skeleton techniques for enhancing motion dynamics in key frame animation. CACM 19, 10, 564--569. Google ScholarDigital Library
- CAPELL, S., GREEN, S., CURLESS, B., DUCHAMP, T., AND POPOVIĆ, Z. 2002. Interactive skeleton-driven dynamic deformations. ACM Transactions on Graphics 21, 3, 586--593. Google ScholarDigital Library
- CATMULL, E. E. 1972. A system for computer generated movies. In Proc. ACM Annual Conf. August, 422--431. Google ScholarDigital Library
- FREEMAN, W. T., AND TENENBAUM, J. B. 1997. Learning bilinear models for two-factor problems in vision. In IEEE Computer Vision and Pattern Recognition. Google ScholarDigital Library
- JAMES, D. L., AND PAI, D. K. 2002. DyRT: Dynamic response textures for real time deformation simulation with graphics hardware. ACM Transactions on Graphics 21, 3, 582--585. Google ScholarDigital Library
- KRY, P. G., JAMES, D. L., AND PAI, D. K. 2002. Eigenskin: Real time large deformation character skinning in hardware. In ACM SIGGRAPH Symposium on Computer Animation, 153--160. Google ScholarDigital Library
- LEWIS, J. P., CORDNER, M., AND FONG, N. 2000. Pose space deformations: A unified approach to shape interpolation and skeleton-driven deformation. In Proceedings of ACM SIGGRAPH 2000, Annual Conference Series, ACM SIGGRAPH. Google ScholarDigital Library
- MAGNENAT-THALMANN, N., LAPERRIRE, R., AND THALMANN, D. 1988. Joint-dependent local deformations for hand animation and object grasping. In Proceedings of Graphics Interface '88, 26--33. Google ScholarDigital Library
- MALANDAIN, G., AND BOISSONNAT, J.-D. 2002. Computing the diameter of a point set. In Discrete Geometry for Computer Imagery (DGCI 2002), A. Braquelaire, J.-O. Lachaud, and A. Vialard, Eds., vol. 2301. Google ScholarDigital Library
- NEBEL, J.-C., AND SIBIRYAKOV, A. 2002. Range flow from stereo-temporal matching: application to skinning. In IASTED International Conference on Visualization, Imaging, and Image Processing.Google Scholar
- SCHEEPERS, F., PARENT, R. E., CARLSON, W. E., AND MAY, S. F. 1997. Anatomy-based modeling of the human musculature. In Proceedings of SIGGRAPH 97, Annual Conference Series, ACM SIGGRAPH, 163--172. Google ScholarDigital Library
- SEDERBERG, T. W., AND PARRY, S. R. 1986. Free-form deformation of solid geometric models. In Proceedings of SIGGRAPH 86, Annual Conference Series, ACM SIGGRAPH, 151--160. Google ScholarDigital Library
- SHOEMAKE, K. 1985. Animating rotation with quaternion curves. In Proceedings of SIGGRAPH 85, Annual Conference Series, ACM SIGGRAPH, 245--254. Google ScholarDigital Library
- SINGH, K., AND FIUME, E. L. 1998. Wires: A geometric deformation technique. In Proceedings of SIGGRAPH 98, Annual Conference Series, ACM SIGGRAPH, 405--414. Google ScholarDigital Library
- SLOAN, P.-P. J., CHARLES F. ROSE, I., AND COHEN, M. F. 2001. Shape by example. In Proceedings of the 2001 symposium on Interactive 3D graphics, 135--143. Google ScholarDigital Library
- TURKOWSKI, K. 1990. Transformations of surface normal vectors. Tech. Rep. 22, Apple Computer, July.Google Scholar
- WANG, X. C., AND PHILLIPS, C. 2002. Multi-weight enveloping: Least-squares approximation techniques for skin animation. In ACM SIGGRAPH Symposium on Computer Animation, 129--138. Google ScholarDigital Library
- WILHELMS, J., AND GELDER, A. V. 1997. Anatomically based modeling. In Proceedings of SIGGRAPH 97, Annual Conference Series, ACM SIGGRAPH, 173--180. Google ScholarDigital Library
Recommendations
Building efficient, accurate character skins from examples
Good character animation requires convincing skin deformations including subtleties and details like muscle bulges. Such effects are typically created in commercial animation packages which provide very general and powerful tools. While these systems ...
Learning an inverse rig mapping for character animation
SCA '15: Proceedings of the 14th ACM SIGGRAPH / Eurographics Symposium on Computer AnimationWe propose a general, real-time solution to the inversion of the rig function - the function which maps animation data from a character's rig to its skeleton. Animators design character movements in the space of an animation rig, and a lack of a general ...
Direct manipulation of interactive character skins
I3D '03: Proceedings of the 2003 symposium on Interactive 3D graphicsGeometry deformations for interactive animated characters are most commonly achieved using a skeleton-driven deformation technique called linear blend skinning. To deform a vertex, linear blend skinning computes a weighted average of that vertex rigidly ...
Comments