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Journal ArticleDOI

Spacetime constraints

Andrew Witkin, +1 more
- pp 159-168
TLDR
This work presents as examples a Luxo lamp performing a variety of coordinated motions that conform to such principles of traditional animation as anticipation, squash-and-stretch, follow-through, and timing.
Abstract
Spacetime constraints are a new method for creating character animation. The animator specifies what the character has to do, for instance, "jump from here to there, clearing a hurdle in between;" how the motion should be performed, for instance "don't waste energy," or "come down hard enough to splatter whatever you land on;" the character's physical structure---the geometry, mass, connectivity, etc. of the parts; and the physical resources' available to the character to accomplish the motion, for instance the character's muscles, a floor to push off from, etc. The requirements contained in this description, together with Newton's laws, comprise a problem of constrained optimization. The solution to this problem is a physically valid motion satisfying the "what" constraints and optimizing the "how" criteria. We present as examples a Luxo lamp performing a variety of coordinated motions. These realistic motions conform to such principles of traditional animation as anticipation, squash-and-stretch, follow-through, and timing.

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Citations
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Journal ArticleDOI

Dextrous manipulation from a grasping pose

TL;DR: An optimization-based approach to synthesizing hand manipulations from a starting grasping pose that takes as input an initial grasping pose and partial object trajectory, and produces as output physically plausible hand animation that effects the desired manipulation.
Journal ArticleDOI

Motion sketching for control of rigid-body simulations

TL;DR: A multiple-shooting optimization estimates the parameters of a rigid-body simulation needed to simulate an animation that matches the sketch with physically plausible timing and motion to physical simulations of multiple colliding rigid bodies possibly connected with joints in a tree (open-loop) topology.
Proceedings ArticleDOI

Animating non-humanoid characters with human motion data

TL;DR: The method provides an alternative for animating non-humanoid characters that leverages motion data from a human subject performing in the style of the target character, and consists of a statistical mapping function learned from a small set of corresponding key poses, and a physics-based optimization process to improve the physical realism.
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Real handball goalkeeper vs. virtual handball thrower

TL;DR: The main originality of this work was to measure presence in a sporting application with new evaluation methods based on motion capture to test if virtual reality is a valid training tool for the game of handball.
Journal ArticleDOI

VideoMocap: modeling physically realistic human motion from monocular video sequences

TL;DR: The power and effectiveness of the video-based motion modeling process in an image-based keyframe animation framework is demonstrated by generating a wide variety of physically realistic human actions from uncalibrated monocular video sequences such as sports video footage.
References
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Book

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Proceedings ArticleDOI

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TL;DR: The description of shape and the description of motion are unified and differential equations that model the behavior of non-rigid curves, surfaces, and solids as a function of time are constructed.
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TL;DR: Kinematically redundant manipulators have a number of potential advantages over current manipulator designs and velocity control through pseudoinverses is suggested for this type of arm.
Proceedings ArticleDOI

Principles of traditional animation applied to 3D computer animation

TL;DR: The basic principles of traditional 2D hand drawn animation and their application to 3D computer animation are described and how these principles evolved is described.