Collision-Avoiding Positioning of Clothing Parts for Preventing Onset Tanglements.

Positioning clothing parts ($\mathcal {S}$Ss) such as sleeves and collars has been in the realm of manual task that had to be done meticulously in order to prevent unnecessary tanglements during the simulation. This article proposes an optimization-based method to computerize the above $\mathcal {S}$S-positioning task. For that, we embed each $\mathcal {S}$S to an abstracting cylinder $\mathcal {C}$C such that $\mathcal {S}$S-positioning can be done by adjusting only 3$\sim$∼4 DOFs (e.g., translating/rotating $\mathcal {C}$C or adjusting its radius) instead of per-vertex-full-DOFs. Then, we formulate an objective function $E$E by scoring undesirableness of $\mathcal {S}$S's position (e.g., $\mathcal {S}$S penetrating the body, $\mathcal {S}$S making cloth-to-cloth intersection). In organizing $E$E into the loop of the Newton's method, the main challenge was to calculate the symbolic gradient and hessian, for which this article makes several novel contributions. The resultant $\mathcal {S}$S-positioning method works quite successfully; $\mathcal {S}^*$S*s (the output of the $\mathcal {S}$S-positioning method) are tanglement-free thus running the simulator to that configuration produces acceptable draping quickly; Experiments show that, in obtaining acceptable draping, the proposed method produces about $\times 9.7$×9.7 speed up compared to when not using it.