Deformable models using displacement constraints

• Main Author: Palazzi, Larry
• Language: English
• Published: 2008
• Online Access: http://hdl.handle.net/2429/1654

This thesis explores a variation of a technique, called "displacement constraints" [19], used for creating and animating deformable objects. It is a constraint-based technique that uncouples the constraint forces from the external forces acting on an object, and solves a system of geometric constraints at each time step using an iterative technique. Displacement Constraints does not attempt to model real physics, but is a simple, efficient technique that offers interactive speeds for the modeling and animation of deformable objects. The inability to respond globally to an external force is an inherent property of many discrete/nodal formulations. A global response is sometimes only obtained through the propagation of localized forces over multiple timesteps. Energy minimization techniques may also achieve certain global effects, but at a higher computational cost. We introduce a multilevel approach to force distribution to improve the global response of a deformable object. External forces acting on an object are propagated through the different levels of the hierarchical representation of the object. Animators can set the distribution of forces at each level, thus controlling an object's local and global behaviour.