Environment-Aware Postural Control of Virtual Humans for Real-time Applications

Abstract

Interactive control of a virtual character through full body movement has a wide range of applications. However, there is a need for systems that accurately reproduce the motion of a performer while accounting for surrounding obstacles. We propose an approach based on an efficient Prioritized Inverse Kinematics constraint solver. The inputs to the system are the acquired positions of relevant body parts. These positions are tracked by the virtual character thanks to a set of kinematic constraints. At the same time a special constraint, which we call "observer", is attached to body parts that must be checked for collisions. An observer acts by smoothly damping the motion of its controlled body part towards nearby obstacles, thus preventing future collisions from taking place.

Accurate on-line avatar control with collision anticipation

“…Our method employs a different approach to Inverse Kinematics, since user-defined sets of joints can be used for the satisfaction of each constraint, and since a different priority can be assigned to each constraint. This has been used in the past in specific contexts, like offline reconstruction of motions from a database where only a reduced subset of the input markers is known [Peinado et al 2006]. In this work we extend this approach to online avatar control from a set of markers which is smaller (and thus less encumbering) than most production setups, yet at the same time allowing for an accurate reconstruction of postures.…”

Full-body performance animation with Sequential Inverse Kinematics

“…Nevertheless, these methods do not take into consideration the limb con- straints a multibody system is subject to for repositioning in case of self-collision. The strategy to avoid self-collisions must be integrated within the IK algorithm as it is shown in the works of Kallmann [47] and Peinado et al [48]. In the present study we integrate a strategy to reorient the upper arms in the SIK method as shown in Algorithm 5.…”