Conference Paper

Staggered Poses: A Character Motion Representation for Detail-Preserving Editing of Pose and Coordinated Timing.

DOI: 10.2312/SCA/SCA08/137-146 Conference: Proceedings of the 2008 Eurographics/ACM SIGGRAPH Symposium on Computer Animation, SCA 2008, Dublin, Ireland, 2008
Source: DBLP

ABSTRACT We introduce staggered poses---a representation of character motion that explicitly encodes coordinated timing among movement features in different parts of a character's body. This representation allows us to provide sparse, pose--based controls for editing motion that preserve existing movement detail, and we describe how to edit coordinated timing among extrema in these controls for stylistic editing. The staggered pose representation supports the editing of new motion by generalizing keyframe--based workflows to retain high--level control after local timing and transition splines have been created. For densely--sampled motion such as motion capture data, we present an algorithm that creates a staggered pose representation by locating coordinated movement features and modeling motion detail using splines and displacement maps. These techniques, taken together, enable feature--based keyframe editing of dense motion data.

0 Bookmarks
 · 
59 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present inverse kinodynamics (IKD), an animator friendly kinematic work flow that both encapsulates short-lived dynamics and allows precise space-time constraints. Kinodynamics (KD), defines the system state at any given time as the result of a kinematic state in the recent past, physically simulated over a short time window to the present. KD is a well suited kinematic approximation to animated characters and other dynamic systems with dominant kinematic motion and short-lived dynamics. Given a dynamic system, we first choose an appropriate kinodynamic window size based on accelerations in the kinematic trajectory and the physical properties of the system. We then present an inverse kinodynamics (IKD) algorithm, where a kinodynamic system can precisely attain a set of animator constraints at specified times. Our approach solves the IKD problem iteratively, and is able to handle full pose or end effector constraints at both position and velocity level, as well as multiple constraints in close temporal proximity. Our approach can also be used to solve position and velocity constraints on passive systems attached to kinematically driven bodies. We describe both manual and automatic procedures for selecting the kinodynamic window size necessary to approximate the dynamic trajectory to a given accuracy. We demonstrate the convergence properties of our IKD approach, and give details of a typical work flow example that an animator would use to create an animation with our system. We show IKD to be a compelling approach to the direct kinematic control of character, with secondary dynamics via examples of skeletal dynamics and facial animation.
    Computers & Graphics 12/2012; 36(8):904-915. · 1.03 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we introduce a method that endows a given animation signal with slow-in and slow-out effects by using a bilateral filter scheme. By modifying the equation of the bilateral filter, the method applies reparameterization to the original animation trajectory. This holds extreme poses in the original animation trajectory for a long time, in such a way that there is no distortion or loss of the original information in the animation path. Our method can successfully enhance the slow-in and slow-out effects for several different types of animation data: keyframe and hand-drawn trajectory animation, motion capture data, and physically-based animation by using a rigid body simulation system.
    Graphical Models 09/2011; 73:141-150. · 0.97 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a system for interactive kinematic editing of motion paths and timing that employs various biomechanical observations to augment and restrict the edited motion. Realistic path manipulations are enforced by restricting user interaction to handles identified along a motion path using motion extrema. An as-rigid-as-possible deformation technique modified specifically for use on motion paths is used to deform the path to satisfy the usermanipulated handle positions. After all motion poses have been adjusted to satisfy the new path, an automatic timewarping step modifies the timing of the new motion to preserve the timing qualities of the original motion. This timewarp is based on biomechanical heuristics relating velocity to stride length and path curvature, as well as the preservation of acceleration for ballistic motion. We show that our system can be used to quickly and easily modify a variety of locomotive motions, and can accurately reproduce recorded motions that were not used during the editing process.
    Proceedings of the 2011 Eurographics/ACM SIGGRAPH Symposium on Computer Animation, SCA 2011, Vancouver, BC, Canada, 2011; 01/2011

Preview

Download
0 Downloads
Available from