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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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Proceedings ArticleDOI

Two-way coupling of rigid and deformable bodies

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Book ChapterDOI

Guided Optimization for Balanced Locomotion

TL;DR: A method of using guiding forces to allow progressive learning of control actions for balanced locomotion is presented and involves using a “hand of God” to facilitate balance while the basic actions of a desired motion are learned.

Nonprehensile robotic manipulation: controllability and planning

TL;DR: This thesis addresses the manipulation capabilities of even the simplest robots under more completemechanics models by studying graspless or nonprehensile manipulation and describes a planner that performs dynamic tasks such as snatching an object from a table, rolling an object on the surface of the arm, and throwing and catching.
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The Kneed Walker for human pose tracking

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Journal ArticleDOI

Creating and retargetting motion by the musculoskeletal human body model

TL;DR: This paper proposes a method to create/retarget human body motions using a musculoskeletal human body model, and can be used for biomechanically correct inverse kinematics, interpolation of motions, and physiological retargetting of the human body motion.
References
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Proceedings ArticleDOI

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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.