Normalized Euclidean distance matrices for human motion retargeting

Abstract

Figure 1: (a) Example pose where the actor's hands come to a close distance. The same pose retargeted on a skeleton with longer forearms by (b) simply transferring joint angles or (c) using our normalized Euclidean distance matrix approach. ABSTRACTIn character animation, it is often the case that motions created or captured on a specific morphology need to be reused on characters having a different morphology while maintaining specific relationships such as body contacts or spatial relationships between body parts. This process, called motion retargeting, requires determining which body part relationships are important in a given animation. This paper presents a novel frame-based approach to motion retargeting which relies on a normalized representation of body joints distances. We propose to abstract postures by computing all the inter-joint distances of each animation frame and store them in Euclidean Distance Matrices (EDMs). They 1) present the benefits of capturing all the subtle relationships between body parts, 2) can be adapted through a normalization process to create a morphologyindependent distance-based representation, and 3) can be used to efficiently compute retargeted joint positions best satisfying newly computed distances. We demonstrate that normalized EDMs can be efficiently applied to a different skeletal morphology by using a Distance Geometry Problem (DGP) approach, and present results on a selection of motions and skeletal morphologies. Our approach opens the door to a new formulation of motion retargeting problems, solely based on a normalized distance representation.ACM acknowledges that this contribution was authored or co-authored by an employee, contractor or affiliate of a national government. As such, the Government retains a nonexclusive, royalty-free right to publish or reproduce this article, or to allow others to do so, for Government purposes only.

An application-based characterization of dynamical distance geometry problems

“…By representing this animation by distances, we can construct the graph G with the edge set E * as in equ. (1), where our depth parameter τ is set to 3. Moreover, we added the following set of edges:…”

“…This is a very delicate step, because the inclusion of large changes in the modified distances may cause large distance incompatibilities, and spoil the simulations. One possible technique for modifying the distances related to pairs {u, v} ∈ E S in accordance with new skeletal structure was recently presented in [1,23]. Some preliminary results can be viewed in a video clip associated to the paper [1] (downloadable from the conference website).…”

Введение Расстояния Взаимодействия В Контексте Геометрии Расстояния Для Движений Человека

“…3, representing the animation of character A, to character B (in other words, it is imposed that ≡ ). However, the Euler angles in are not able to take into consideration the spatial relationship between pairs of character joints [2,10], and as a consequence undesired effects may be introduced in the animation. Typical undesired effects include creating body contacts that were not present in the original animation, or to miss body contacts that actually occur in the original animation.…”

Introducing the Interaction Distance in the context of Distance Geometry for Human Motions

“…It is important to point out the two different roles of and in equ. (2). The former is one of the weights associated to the edges of the graph , which corresponds to the available distance value between a vertex pair.…”

“…This article focuses on a particular application of the dynDGP, where the main interest is in analyzing human motions through the study of animated skeletal structures which resemble the human body [20]. Some initial works have shown that tools for distance geometry can be employed in this context [2,17], but they consider, as in the majority of the applications in distance geometry, the Euclidean distance as a metric.…”