Continuum Foam: A Material Point Method for Shear-Dependent Flows

We consider the simulation of dense foams composed of microscopic bubbles, such as shaving cream and whipped cream. We represent foam not as a collection of discrete bubbles, but instead as a continuum. We employ the Material Point Method (MPM) to discretize a hyperelastic constitutive relation augmented with the Herschel-Bulkley model of non-Newtonian plastic flow, which is known to closely approximate foam behavior. Since large shearing flows in foam can produce poor distributions of material points, a typical MPM implementation can produce non-physical internal holes in the continuum. To address these artifacts, we introduce a particle resampling method for MPM. In addition, we introduce an explicit tearing model to prevent regions from shearing into artificially-thin, honey-like threads. We evaluate our method fs efficacy by simulating a number of dense foams, and we validate our method by comparing to real-world footage of foam. http://www.cs.columbia.edu/cg/foam/ http://www.cs.columbia.edu/~yonghao/ http://breannansmith.com/ https://cs.uwaterloo.ca/~c2batty/ http://www.cs.columbia.edu/~cxz/ http://www.cs.columbia.edu/~eitan/