About Publication

• “A material point method for snow simulation”
  • Authors: Stomakhin, Alexey and Schroeder, Craig and Chai, Lawrence and Teran, Joseph and Selle, Andrew
  • Conference: ACM SIGGRAPH 2013
  • "Augmented MPM for phase-change and varied materials" ACM SIGGRAPH 2014

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Contribution to works

Referred from Amazon

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Contribution in this paper

1. Develop and use semi-implicit MPM (Material Point Method) for complex snow scene
2. Construct constitutive model for intuitive user control

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Why using snow in animation was challenging?

• variety because of environment factors (e.g., freshness, water/ice content)
• related works: sand (diff: no compressibility)

referred from Deviant Art

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Motivation

Empirical snow model based on phonological observation

referred from disney wikia

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Focusing Snow Features

1. Volume preservation (質量保存)
2. Stiffness (剛性)
3. Plasticity (可塑性)
4. Fracture (破砕)

• Note that it is trade-off between 2 and 3, and this paper approach picks up plasticity

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MPM Concept

Track particles' configuration defined with three features.
- mass (質量)
- momentum (弾力性)
- deformation gradient (変形勾配)

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Proposed Architecture

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Why do they employ two-stage velocity parameter update?

• Answer: They considers the reaction against other objects

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Demo

SIGGRAPH Demo

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Summary

• The first snow representation challenge in 3D animation
• Hidden background about a popular movie