R. Boulic and D. Thalmann. Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, 11(4):189--202, 1992.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....all the degrees of freedom, leading to smooth and parameterizable walking gaits. Note that the same kind of approach has more recently been used for the animation of human running [10] Another way to maintain extra constraints on the foot position is to use inverse kinematic algorithms [22, 21, 4, 6]. Boulic et al. 4] first use a standard forward kinematics approach, generating key positions that are interpolated. A leg correction process is then used to modify invalid in between postures: 5 if a foot penetrates the ground, an inverse kinematic algorithm is applied to modify its position, ....

R. Boulic and D. Thalmann. Combined direct and inverse kinematic control for articulated figures motion editing. Computer Graphics Forum, 11(4):189--202, 1992. 17

.... Instead of trying to follow the original trajectories of the end effectors, the algorithm puts some constraints on these end effectors and uses an inverse kinematics (IK) or optimisation solver to find a motion that satisfy these constraints and preserve the original motion as well as possible [3, 4, 5]. These methods are more advanced than the trajectory preserving method. However, they are not perfect too. The bottleneck of these methods is definition of constraints. Some algorithms rely on global constraints (such as feet above the ground constraint) and fail to correct artefacts that cannot ....

R. Boulic and D. Thalmann, (1992). "Combined Direct and Inverse Kinematic Control for Articulated Figures Motion Editing", Computer Graphics Forum, 11(4), 189-202

....local methods, feasible in real time, only compute an optimal change in q, dq for a small change in x, dx and then integrate dq to generate the entire joint space path [10] These kinematics approaches prove to be computationally efficient. They are used in robotics [11] and in computer animation [12 14]. However the local or global solutions are based on the definition of a criteria which does not ensure that the produced movement looks realistic. Therefore if these methods cannot be ignored since they are largely used in most graphics commercial software, they are not of prime importance ....

Boulic, R., Thalmann D.: Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, vol 11, n4, (1992) 189-202

....simulating all the degrees of freedom, leading to smooth and parameterizable walking gaits. Note that the same kind of approach has more recently been used for the animation of human running [9] Another way to maintain extra constraints on the foot position is to use inverse kinematic algorithms [20, 4, 6]. Boulic et al. 4] rst use a standard direct kinematics approach, generating key positions that are interpolated. A ileg correction process is then used to modify invalid in between postures: if a foot penetrates the ground, an inverse kinematic algorithm is applied to modify its position, thus ....

R. Boulic and D. Thalmann. Combined direct and inverse kinematic control for articulated gures motion editing. Computer Graphics Forum, 11(4):189202, 1992.

.... measurements and the difference in the anthropometry and step length can lead to a problem in the walking animation: there exists a closed loop (two legs and supporting plane) during the double stance phase, and it may lead to constraint violations such as floating, penetrating, or skidding foot [13, 11]. The global motion may not be continuous, especially between the steps. We call the process of generating the walking data of different anthropometric figures in stepping an arbitrary step from an original set of measured data as kinematic generalization. We pursue this topic in greater detail ....

....Bruderlin and Calvert [16] recently proposed a kinematic parametrization of walking motion to obtain a variety of interactively specified, personalized, real time human locomotion patterns. Boulic et al. tried a generalization of experimental data based on the normalized velocity of walking [13, 11]. Their generalization can produce the parameters which might violate, in its direct application, some of the constraints imposed on walking. They overcome this problem through a correction phase based on inverse kinematics. To preserve the original characteristics of the walking data, they ....

Ronan Boulic and Daniel Thalmann. Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, 11(4):189--202, 1992.

....automobile and aerospace industries started working on modeling paradigms and techniques many decades ago. Humans and other animals have highly complex shapes, and are quite difficult to model, accounting for the remainder of the difficulty. Motion control has been the subject of much research [27, 14, 18, 49, 17, 15, 33, 9, 3], but producing a desired motion is still quite difficult. If the motion is intended to be realistic (rather than cartoon ish) then the problem is exacerbated further by the fact that humans are exceedingly sensitive to the most subtle errors in movement or surface deformation. This state of ....

Ronan Boulic and Daniel Thalmann. Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, 21:189--202, 1992.

....of Fourier series [NAC94, NAHR95] The idea was that the gait pattern could be fine tuned by optimizing the wavelet coefficients. Such flexibility could be used for steering the synthetic animal towards a desired target. A similar idea of real time adaptation of the gait was also expressed in [BT92a, BT92b]. Apart from its quasi periodic, modulated nature, there is another interesting feature in animal locomotion: this is the pulse like activation of the propellingmuscles. Indeed, for a variety of locomotion modes, such as a bird s rowed flight [Ren94, DKGJ88] muscles are activated rather ....

....the muscle activation pattern. The scope of this technique should thus encompass aquatic and aerial locomotion with no major difficulty as future works will try to demonstrate. Legged locomotion may be more difficult because sensory information for terrain adaptation may be needed, as in [dPF93, BT92a, BT92b]. Pulse modulation can be an efficient tool for controlling the locomotion of a variety of computer animated animals. The three above mentionned examples are interesting because there is problably no other efficient way to control them than the method we propose here: locomotion is controlled ....

Boulic (R.) et Thalmann (D.). -- Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, vol. 11, n4, October 1992, pp. 189--202.

....an effect without any knowledge about its cause. Each object is described by a set of parameters P 2 R n . This model describes explicitly how these parameters varies over time (P = f(t) This kind of models includes key frame animation techniques and procedural methods like inverse kinematics [6] or AFFD [8] In key frame techniques, a subset of instantaneous states fP (t 0 ) P (t k )g are expressed either absolutely or relatively over time, and by interpolation a spatio temporal trajectory is obtained in the system description space. In this case, the state of the system at each ....

R. Boulic. -- Combined direct and inverse kinematic control for articulated figure motion editing. -- Computer Graphics Forum, 11(4):189--202, 1992.

....the definition of a ready to use model for animated gaits. 1 Introduction Motion control techniques for computer animation can be divided into two main streams : on the one hand, kinematic approaches such as keyframing or inverse kinematics make it possible to modify motion trajectories directly [16, 29, 24, 21, 3, 2]. The important drawback is that such approaches give too much freedom to the animator in the sense that physical laws such as newtonian mechanics may easily be infringed, with a significant loss in terms of realism. On the other hand, dynamic approaches [1, 19, 15, 32] ensure that the generated ....

R. Boulic. Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, 11(4):189--202, 1992.

....By controlling Deltat we can adjust the number of frames to be generated for a step depending on the machine speed. For the walking animation, a biomechanical measurement of straight line walking is generalized to the given body size and adjusted for any path curvature, turning, or steps [14, 13, 1, 5, 6]. The motion characteristics of the original gait are preserved during the generalization even if the step direction or step length is changed [14] Therefore several different walking styles can be adopted merely by acquiring multiple sets of measurements. Fig. 4 shows a few frames from a curved ....

Ronan Boulic and Daniel Thalmann. Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, 11(4):189--202, 1992.

.... may be effectively specified by the animator [8] Deformation control of linked articulated rigid bodies is another big challenge, together with its ultimate application: animation of the human body [2, 21] Using inverse kinematics, the shape is deduced from end effector goal positionning [6, 2]. With dynamics based techniques [23, 13, 25] deformation results from the applied torques. In either cases, deformation is treated as an a posteriori effect. We tackle the problem from the opposite direction, and choose to impose the shape of an articulated object, rather than to observe it. In ....

R. Boulic. Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, 11(4):189--202, 1992.

....all the degrees of freedom, leading to smooth and parameterizable walking gaits. Note that the same kind of approach has more recently been used for the animation of human running [BC96] Another way to maintain extra constraints on the foot position is to use inverse kinematic algorithms [GM85, BMTT90, BT92]. Boulic et al. BMTT90] first use a standard direct kinematics approach, generating key positions that are interpolated. A leg correction process is then used to modify invalid in between postures: if a foot penetrates the ground, an inverse kinematic algorithm is applied to modify its ....

R. Boulic and D. Thalmann. Combined direct and inverse kinematic control for articulated

....Figure Animation, Motion Editing, Direct Kinematics, Inverse Kinematics, Key framing . 1 Introduction Human animation is an active research field, including various approaches from traditional rotoscopy [1] key framing [2,3,4,5] functional modeling [6,7,8,9] direct and inverse kinematics [10,11,12], to physically based methods like direct and inverse dynamics [13,14,15] and space time optimization [16,17] Integration of different motion generators is vital for the design of complex motion where the characterization of movement can quickly change in terms of functionality, goals and ....

....multiple track sequences. The first is usually a compression filter used to reduce the key value to minimum within a predefined error rate. Among these tools is also the Coach Trainee method which allows the kinematic correction of joint space based motion with respect to Cartesian constraints [11,12]. In such a way, it is still possible to modify the key frame sequence, a low level description of motion, for a higher level goal oriented requirement. In the following sections, we first recall the basic features of the 3D hierarchy and the structure of the associated multiple track sequence. ....

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Boulic R, Thalmann D (1992) Combined Direct and Inverse Kinematic Control for Articulated Figures Motion Editing, Computer Graphics Forum, Vol2(4), October 1992.

....case of a digital actor, it essentially consists in describing the evolution over time of the joint angles of a hierarchical structure called skeleton. A general motion control system should be a combination of various techniques: motion capture [ 1 ] keyframe [ 2 3 4 5 ] inverse kinematics [ 6 7 ], physically based methods like direct and inverse dynamics [ 8 9 ] spacetime constraints [ 10 11 12 ] functional models of walking [ 13 14 15 ] Fig.1) and intelligent grasping [ 16 17 ] Fig.2) Integration of different motion generators is vital for the design of complex motion where ....

R. Boulic and D. Thalmann (1992) "Combined Direct and Inverse Kinematic Control for Articulated Figures Motion Editing," Computer Graphics Forum, Vol.2, No.4), October 1992.

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R. Boulic and Thalmann D. "Combined direct and inverse kinematic control for articulated figure motion editing", Computer Graphics Forum, 2(4) (October 1992).

....Figure Animation, Motion Editing, Direct Kinematics, Inverse Kinematics, Keyframing . 1. Introduction Human animation is an active research field, including various approaches from traditional rotoscopy [1] key framing [2,3,4,5] functional modelling [6,7,8,9] direct and inverse kinematics [10,11,12], to physically based methods like direct and inverse dynamics [13,14,15] and spacetime optimization [16,17] Integration of different motion generators is vital for the design of complex motion where the characterization of movement can quickly change in terms of functionality, goals and ....

....multiple track sequences. The first is usually a compression filter used to reduce the key value to minimum within a predefined error rate. Among these tools is also the Coach Trainee method which allows the kinematical correction of joint space based motion with respect to cartesian constraints [11,12]. In such a way, it is still possible to modify the key frame sequence, a low level description of motion, for a higher level goal oriented requirement. In the following sections, we first recall the basic features of the 3D hierarchy and the structure of the associated multiple track sequence. ....

[Article contains additional citation context not shown here]

Boulic R, Thalmann D (1992) Combined Direct and Inverse Kinematic Control for Articulated Figures Motion Editing, Computer Graphics Forum, Vol. 2, No.4, October 1992, pp.189-202.

....the animator is still left a large responsibility in the editing of motion coming from Performance Animation systems. There is also a need to improve motion editing methods in order to enforce the cartesian constraints lost in the acquisition process while retaining the initial motion dynamics [20] [12] Recent advances in motion signal processing are also worth mentioning in that respect [21] 13] 3 The interactive simulation environment Apart from the wide range of commercial systems providing interactive response time for the purpose of animation design, we can consider here the systems ....

Boulic R. , Thalmann D. "Combined Direct and Inverse Kinematic Control for Articulated Figure Motion Editing", Computer Graphics Forum ,2(4), pp , October 1992, partly integrated in Course notes n80, SIGGRAPH 93, Anaheim, California, August 93.

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Ronan Boulic and Daniel Thalmann. Combined direct and inverse kinematic control for articulated figure motion editing. Computer graphics forum, 2(4):189--202, 1992.

....The specific challenge of creating tools for human animation has been taken on by few. The work of Badler et al. 2] Magnenat Thalmann and Thalmann[17] and Boulic et al. 4] illustrate the present state of the art in modeling humans using predominantly kinematic methods. The method presented in [3] includes the use of kinematicallyguided corrections to motions. A method of generalizing existing rotoscope data while preserving original motion characteristics is presented in [14] Beyond kinematic methods, there have been several proposals to produce animated walking motions using ....

R. Boulic, D. Thalmann. Combined Direct and Inverse Kinematic Control for Articulated Figures Motion Editing. Computer Graphics Forum, 2 (4), 1992, 189-202.

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R. Boulic and D. Thalmann. Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, 11(4):189--202, 1992.

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Boulic R. and Thalmann D., Combined Direct and Inverse Kinematic Control for Articulated Figure Motion Editing. Computer Graphics Forum, 11(J):189-202, 1992.

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Ronan Boulic and Daniel Thalmann. Combined direct and inverse kinematic control for articulated figure motion editing. Computer Graphics Forum, 11(4):189--202, 1992.

No context found.

Ronan Boulic and D.Thalmann. Combined direct and inverse kinematic control for articulated figures motion editing. Computer Graphics Forum, 11(4):189--202, 1992.

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