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Journal ArticleDOI

Spacetime constraints

01 Jun 1988-pp 159-168
TL;DR: 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.
Citations
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Proceedings ArticleDOI
Michael Gleicher1
24 Jul 1998
TL;DR: In this article, a spacetime constraints solver computes an adapted motion that re-establishes these constraints while preserving the frequency characteristics of the original signal, and demonstrate their approach on motion capture data.
Abstract: straints, motion capture. In this paper, we present a technique for motion: the problem of adapting an animated motion from one character to another. Our focus is on adapting the motion of one articulated figure to another figure with identical structure but different segment lengths, although we use this as a step when considering less similar characters. Our method creates adaptations that preserve desirable qualities of the original motion. We identify specific features of the motion as constraints that must be maintained. A spacetime constraints solver computes an adapted motion that re-establishes these constraints while preserving the frequency characteristics of the original signal. We demonstrate our approach on motion capture data.

815 citations

Proceedings ArticleDOI
15 Sep 1995
TL;DR: Multiresolution motion filtering, multitarget motion interpolation with dynamic timewarping, waveshaping and motion displacement mapping are introduced, complementary to keyframing, motion capture, and procedural animation.
Abstract: Techniques from the image and signal processing domain can be successfully applied to designing, modifying, and adapting animated motion. For this purpose, we introduce multiresolution motion filtering, multitarget motion interpolation with dynamic timewarping, waveshaping and motion displacement mapping. The techniques are well-suited for reuse and adaptation of existing motion data such as joint angles, joint coordinates or higher level motion parameters of articulated figures with many degrees of freedom. Existing motions can be modified and combined interactively and at a higher level of abstraction than conventional systems support. This general approach is thus complementary to keyframing, motion capture, and procedural animation.

744 citations

Proceedings ArticleDOI
15 Sep 1995
TL;DR: Algorithm for the animation of male and female models performing three dynamic athletic behaviors: running, bicycling, and vaulting using control algorithms that cause a physically realistic model to perform the desired maneuver.
Abstract: This paper describes algorithms for the animation of male and female models performing three dynamic athletic behaviors: running, bicycling, and vaulting. We animate these behaviors using control algorithms that cause a physically realistic model to perform the desired maneuver. For example, control algorithms allow the simulated humans to maintain balance while moving their arms, to run or bicycle at a variety of speeds, and to perform two vaults. For each simulation, we compare the computed motion to that of humans performing similar maneuvers. We perform the comparison both qualitatively through real and simulated video images and quantitatively through simulated and biomechanical data.

696 citations

Proceedings ArticleDOI
15 Sep 1995
TL;DR: It is shown that whole families of realistic motions can be derived from a single captured motion sequence using only a few keyframes to specify the motion warp.
Abstract: We describe a simple technique for editing captured or keyframed animation based on warping of the motion parameter curves. The animator interactively defines a set of keyframe-like constraints which are used to derive a smooth deformation that preserves the fine structure of the original motion. Motion clips are combined by overlapping and blending of the parameter curves. We show that whole families of realistic motions can be derived from a single captured motion sequence using only a few keyframes to specify the motion warp. Our technique makes it feasible to create libraries of reusable “clip motion.”

660 citations


Cites methods from "Spacetime constraints"

  • ...A physically based technique in the spirit of [10] might overcome this limitation....

    [...]

Proceedings ArticleDOI
01 Jul 2002
TL;DR: This paper presents a framework that generates human motions by cutting and pasting motion capture data and can easily synthesize multiple motions that interact with each other using constraints, allowing a variety of choices for the animator.
Abstract: There are many applications that demand large quantities of natural looking motion. It is difficult to synthesize motion that looks natural, particularly when it is people who must move. In this paper, we present a framework that generates human motions by cutting and pasting motion capture data. Selecting a collection of clips that yields an acceptable motion is a combinatorial problem that we manage as a randomized search of a hierarchy of graphs. This approach can generate motion sequences that satisfy a variety of constraints automatically. The motions are smooth and human-looking. They are generated in real time so that we can author complex motions interactively. The algorithm generates multiple motions that satisfy a given set of constraints, allowing a variety of choices for the animator. It can easily synthesize multiple motions that interact with each other using constraints. This framework allows the extensive re-use of motion capture data for new purposes.

651 citations

References
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Journal ArticleDOI

17,845 citations

Book
01 Jan 1951

10,667 citations

Proceedings ArticleDOI
01 Aug 1987
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.
Abstract: The theory of elasticity describes deformable materials such as rubber, cloth, paper, and flexible metals. We employ elasticity theory to construct differential equations that model the behavior of non-rigid curves, surfaces, and solids as a function of time. Elastically deformable models are active: they respond in a natural way to applied forces, constraints, ambient media, and impenetrable obstacles. The models are fundamentally dynamic and realistic animation is created by numerically solving their underlying differential equations. Thus, the description of shape and the description of motion are unified.

2,093 citations


"Spacetime constraints" refers background in this paper

  • ...[7, 14, 15, 1, 13, 4, 6] The appeal of physical simulation as an animation technique lies in its promise to produce realistic motion automatically by applying the same physical laws that govern real objects’ behavior....

    [...]

Journal ArticleDOI
01 Apr 1983
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.
Abstract: Kinematically redundant manipulators have a number of potential advantages over current manipulator designs. For this type of arm, velocity control through pseudoinverses is suggested. Questions associated with pseudoinverse control are examined in detail and show that in some cases this control leads to undesired arm configurations. A method for distributing joint angles of a redundant arm in a good approximation to a true minimax criterion is described. In addition several numerical considerations are discussed.

1,007 citations


"Spacetime constraints" refers background in this paper

  • ...The latter problem is well treated by the pseudo-inverse [8, 4], which provides least-squares solutions to overconstrained problems, and minimal solutionsto underconstrainedones....

    [...]

Proceedings ArticleDOI
01 Aug 1987
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.
Abstract: This paper describes the basic principles of traditional 2D hand drawn animation and their application to 3D computer animation. After describing how these principles evolved, the individual principles are detailed, addressing their meanings in 2D hand drawn animation and their application to 3D computer animation. This should demonstrate the importance of these principles to quality 3D computer animation.

740 citations


"Spacetime constraints" refers background in this paper

  • ...John Lasseter spelled this out clearly in his presentation to Siggraph ’87 [9]....

    [...]