Position‐Based Skinning for Soft Articulated Characters

Abstract

In this paper, we introduce a two-layered approach addressing the problem of creating believable mesh-based skin deformation. For each frame, the skin is first deformed with a classic linear blend skinning approach, which usually leads to unsightly artefacts like the well-known candy-wrapper effect and volume loss. Then we enforce some geometric constraints which displace the positions of the vertices to mimic the behavior of the skin and achieve effects like volume preservation and jiggling. We allow the artist to control the amount of jiggling and the area of the skin affected by it. The geometric constraints are solved using a Position-Based Dynamics schema. We employ a graph coloring algorithm for parallelizing the computation of the constraints. Being based on PositionBased Dynamics guarantees efficiency and real-time performances while enduring robustness and unconditional stability. We demonstrate the visual quality and the performance of our approach with a variety of skeleton-driven soft body characters.

Position‐Based Simulation of Elastic Models on the GPU with Energy Aware Gauss‐Seidel Algorithm

“…Deul and Bender [DB13] employed constrained projections for collision handling during simulating the elastic behavior of the skin. Abu Rumman and Fratarcangeli [RF15] incorporated the constraint projections and linear blend skinning for the articulated characters. Elastic rod simulations have been taking the advantage of the PBD method.…”

An adaptive character skinning algorithm based on the property of real skin

“…17 However, this method may result in abnormal scaling and volume loss. 19 However, the high-level simulation costs a lot of computation, and the algorithm needs many manual parameters to be inputted. Spline-based method uses a spline to represent each bone instead of using a matrix rotation.…”

“…Spline-based method uses a spline to represent each bone instead of using a matrix rotation. 19 However, the high-level simulation costs a lot of computation, and the algorithm needs many manual parameters to be inputted.…”

“…This method can generate a more realistic deformation; even the secondary effects such as the jiggling of soft tissues can be simulated when the body is moving. 19 However, even the latest optimized algorithms 20 cannot reach the requirement in real-time applications. 21 Furthermore, once the parameters of this algorithm are set, the actual effect generated in every animation frame cannot be controlled and predicted.…”

Position‐based simulation of cloth wetting phenomena

“…Macklin et al presented a unified PBD framework, which employs particles connected by constraints as the fundamental building block, to model real‐time gases, liquids, deformable solids, rigid bodies, and cloth with two‐way interactions. In addition, position‐based facial animation synthesis and skinning also have been researched.…”