Obscuring length changes during animated motion

In this paper we examine to what extent the lengths of the links in an animated articulated-figure can be changed without the viewer being aware of the change. This is investigated in terms of a framework that emphasizes the role of attention in visual perception. We conducted a set of five experiments to establish bounds for the sensitivity to changes in length as a function of several parameters and the amount of attention available. We found that while length changes of 3% can be perceived when the relevant links are given full attention, changes of over 20% can go unnoticed when attention is not focused in this way. These results provide general guidelines for algorithms that produce or process character motion data and also bring to light some of the potential gains that stand to be achieved with attention-based algorithms.

[1]  P. Cavanagh,et al.  Attention-based visual routines: sprites , 2001, Cognition.

[2]  Heiko Hecht,et al.  Psychological Evidence for Unconscious Processing of Detail in Real-time Animation of Multiple Characters , 2000, Comput. Animat. Virtual Worlds.

[3]  John Dingliana,et al.  Collisions and perception , 2001, TOGS.

[4]  G. Békésy,et al.  Adaptive threshold estimation with unforced-choice tasks , 2002 .

[5]  Jeremy M. Wolfe,et al.  Getting beyond the serial/parallel debate in visual search: a hybrid approach , 2001 .

[6]  Lucas Kovar,et al.  Footskate cleanup for motion capture editing , 2002, SCA '02.

[7]  Frans A. J. Verstraten,et al.  Limits of attentive tracking reveal temporal properties of attention , 2000, Vision Research.

[8]  Eric Horvitz,et al.  Perception, Attention, and Resources: A Decision-Theoretic Approach to Graphics Rendering , 1997, UAI.

[9]  K. Verfaillie,et al.  Detection of intrasaccadic displacements and depth rotations of moving objects , 2002, Vision Research.

[10]  H. Bastian.  Sensation and Perception.—I , 1869, Nature.

[11]  Z W Pylyshyn,et al.  Tracking multiple independent targets: evidence for a parallel tracking mechanism. , 1988, Spatial vision.

[12]  Antonio Torralba,et al.  Top-down control of visual attention in object detection , 2003, Proceedings 2003 International Conference on Image Processing (Cat. No.03CH37429).

[13]  Michael C. Mozer,et al.  Computational modeling of spatial attention , 1996 .

[14]  Thanh Giang,et al.  Evaluating the visual fidelity of physically based animations , 2003, ACM Trans. Graph..

[15]  D. Simons,et al.  Moving and looming stimuli capture attention , 2003, Perception & psychophysics.

[16]  D. Simons,et al.  Change Blindness in the Absence of a Visual Disruption , 2000, Perception.

[17]  Robert J Snowden,et al.  Perception of visual motion , 2002 .

[18]  Jessica K. Hodgins,et al.  Perception of Human Motion With Different Geometric Models , 1998, IEEE Trans. Vis. Comput. Graph..

[19]  Nancy S. Pollard,et al.  Perceptual metrics for character animation: sensitivity to errors in ballistic motion , 2003, ACM Trans. Graph..

[20]  C. Chabris,et al.  Gorillas in Our Midst: Sustained Inattentional Blindness for Dynamic Events , 1999, Perception.

[21]  P. Cavanagh,et al.  Attentional resolution , 1997, Trends in Cognitive Sciences.

[22]  M. M. Taylor,et al.  PEST: Efficient Estimates on Probability Functions , 1967 .