## 2022/07/21, v6: - Added a missing \delta t on the second term of the left-hand side of Eq. 14 and in line 10 of Alg. 3. - Slightly transformed the right-hand side of Eq. 14 so it matches Eq. 13 more closely. ## 2021/12/20, v5: - Corrected the formula for the friction acceleration (Eq. 24). ## 2021/08/04, v4: - Removed incorrect h^3 factor in boundary particle volume calculation in Section 3.4. ## 2021/06/18, v3: - Fixed multiple typos. - Added missing dot product signs in Eq. 6, Eq. 8, Eq. 24 and Eq. 25. - Updated Fig. 3 and additional analysis video to fix right-most cylinder not turning invisible when turning inactive. - Added references to Weiler et al. [2016] and Bouaziz et al. [2014]. ## 2020/07/20, v2: - Extended Eq. 17 to clarify the implementation. ## 2020/04/27, v1: - Author's version of the manuscript that was submitted to SIGGRAPH 2020.