“Avatar: Bending Rigid Bodies” by Criswell, Lentine and Sauers
Conference:
Type(s):
Title:
- Avatar: Bending Rigid Bodies
Session/Category Title: Blowing $h!t Up
Presenter(s)/Author(s):
Abstract:
Simulating bending and denting of rigid materials has become an increasingly important aspect for modeling the realistic destruction of objects. Historically, modeling these phenomena has been a tedious and time consuming process for the artists at Industrial Light & Magic. Typically the artists would manually shape the rigid bodies after the simulation to produce this realistic look. However, for the movie Avatar, we have developed a new system that seamlessly transitions between rigid and deformable simulations allowing the artists to achieve realistic destruction without the need to apply any post corrective shapes.
To solve this problem, we used a low resolution spring-mass simulation as a preprocessing step to the rigid body simulator. At the start of the simulation, a tetrahedral and thin shell representation of the rigid bodies was initialized as a spring cage to model the sur- face deformations during the rigid simulation. At the beginning of each relevant frame, the cages were advanced using a spring-mass simulator and their resulting deformations were transferred to the surface of the rigid bodies. After all the objects are processed, the rigid bodies were advanced using a rigid body simulator. The results allowed for a quick and realistic deformation of rigid bodies that could be used for complex scenes such as those shown in the image.
References:
BRIDSON, R., MARINO, S., AND FEDKIW, R. 2003. Simulation of clothing with folds and wrinkles. In Proc. of the 2003 ACM SIGGRAPH/Eurographics Symp. on Comput. Anim., 28–36.
GUENDELMAN, E., BRIDSON, R., AND FEDKIW, R. 2003. Nonconvex rigid bodies with stacking. ACM Trans. Graph. (SIGGRAPH Proc.) 22, 3, 871–878.
