Abstract We describe a computer vision system for observing the “action units” of a face using video sequences as input. The visual observation (sensing) is achieved by using an optimal estimation optical flow method coupled with a geometric and a physical (muscle) model describing the facial structure. This modeling results in a time-varying spatial patterning […]
Irfan Essa’s MS Thesis (1990) on “Contact detection, collision forces and friction for physically based virtual world modeling”
Abstract Detection of contact and calculation of collision forces is an important problem in any kind of physical multi-body simulation. For computer graphics and physically-based animation, it is especially important to devise methods that combine efficient computational methods with powerful existing graphics tools if one is to obtain a realistic, real-time virtual world. Most of the physical simulations are computationally expensive, […]
Paper in ACM SIGGRAPH Symposium on Interactive 3D Graphics (1990) “The ThingWorld modeling system: Virtual Sculpting by Modal Forces”;
We describe a real-time solid modeling system that is based on the physical analogy of forming clay by applying forces. The system is implemented by simulating real materials as they react to user-supplied forces. Unlike other physically-based modeling approaches, the Thingworld system allows the user to restrict forming action to simple global deformations during the initial “roughing in” phase of modeling, and then later concern themselves with detailing.