M. Nahas, H. Huitric, and M. Saintourens. Animation of a B-Spline figure. The Visual Computer, (3):272--276, 1988.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....(3.2) where [u] 1 u u : u k;1 ] and [v] 1 v v : v m;1 ] We choose the parameters u and v to vary over the interval [0:0# 1:0] for each surface patch, and different basis functions B u and B v are used according to the type and order of the surface. Waite [75] and Nahas et al. [49] used bicubic B spline surface modeling techniques to model faces with relatively few control points. However, using few control points means sacrificing from the detail in the model, and also places like creases become difficult to implement as they require defeating surface continuity ....

M. Nahas, H. Huitric, and M. Sanintourens. Animation of a B-spline figure. The Visual Computer, 3(5):272--276, 1988.

....a large number of works in facial animation based on geometry deformation. Vector based muscle models [14, 18] offer simple and compact representations, however no automatic means of placing muscles within a person specific mesh have been reported. Other deformation methods include spline models [19, 20], and free form deformations [21, 22] See [9] for an excellent survey of these and other methods. Skin wrinkles and creases can be modeled by physically based mass spring system [16, 17] These methods produce geometry deformations with static skin texture. Tuning these to produce a particular ....

M. Nahas, H. Huitric, and M. Saintourens, Animation of a B-spline figure, The Visual Computer, 1988, vol. 3(5), pp. 272-276

.... Geometric manipulations include key framing and geometric interpolations [33, 86, 91] parameterizations [21, 88, 89, 90] finite element methods [6, 44, 102] muscle based modeling [70, 96, 101, 106, 107, 110, 122, 131] visual simulation using pseudo muscles [50, 71] spline models [79, 80, 125, 126, 127] and free form deformations [24, 50] Image manipulations include image morphing between 2 photographic images [10] texture manipulations [82] image blending [103] and vascular expressions [49] At the preprocessing stage, a person specific individual model may be constructed using ....

....Fascia nodes: 4, 5, 6 Bone nodes: 7, 8, 9 Both dotted lines and solid lines indicate elastic spring connections between nodes. 2 4 5 6 7 8 9 epidermal surface dermal fatty layer muscle layer 1 skull surface 3 7 shell facial mesh. Muscle forces are simulated in the form of splines [79, 80, 125, 126, 127], wires [116] or free form deformations [24, 50] 6.1. Free form deformation Free form deformation (FFD) deforms volumetric objects by manipulating control points arranged in a three dimensional cubic lattice [114] Conceptually, a flexible object is embedded in an imaginary, clear, and ....

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M. Nahas, H. Huitric, and M. Saintourens, Animation of a B-spline figure, The Visual Computer, 1988, vol. 3(5), pp. 272-276

....a large number of works in facial animation based on geometry deformation. Vector based muscle models [14, 18] offer simple and compact representations, however no automatic means of placing muscles within a person specific mesh have been reported. Other deformation methods include spline models [19, 20], and free form deformations [21, 22] See [9] for an excellent survey of these and other methods. Skin wrinkles and creases can be modeled by physically based mass spring system [16, 17] These methods produce geometry deformations with static skin texture. Tuning these to produce a particular ....

M. Nahas, H. Huitric, and M. Saintourens, Animation of a B-spline figure, The Visual Computer, 1988, vol. 3(5), pp. 272-276

....also be analyzed. The reader can refer to parts I IV of the EAGLES handbook for more information on speech analysis. When phonemes have been identified they are associated with facial control parameters to compute the appropriate mouth shape. Linear prediction analysis [227] sound segmentation [268], HMM modeling and decoding [405] techniques have been used to generate mouth shapes. ffl Puppeteer control: A puppeteer moves input devices such as dataglove and joysticks, or uses a keyboard to drive a facial model (see Figure 11) Each input device control is associated with a facial parameter ....

....As the puppeteer moves the hand or presses different keys, the facial model moves accordingly. This technique is often used for real time application and movies. ffl Text to visual speech: The input of the system is plain text. The input text is first decomposed into its phonetic representation [182, 287, 39, 195, 268, 399]. Information about phonemes and their duration are automatically generated from the text. Formants and other speech parameters (frequency, pitch, pitch range and so on) are then computed. Text to visual speech technique is suited when parametric facial models are used. Parameters defining facial ....

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M. Nahas, H. Huitric, and M. Saintourens. Animation of a B-spline figure. The Visual Computer, 3(5):272--276, March 1988.

....of real muscles. Two types of muscles are created: linear parallel muscles that pull, and sphincter muscles that squeeze. These muscles are independent of the underlying bone structure, which makes the muscle model independent of specific face topology. The control parameters are based on FACS. Nahas et al. 1988) proposed a method based on B splines. A digitizing system is used to register the position of certain facial points which are organized in a matrix. The matrix is used as a set of control points for a 5 dimensional bicubic B spline surface. Motion of the face is obtained by moving these control ....

Nahas M, Huitric H, Saintourens M (1988), Animation of a B-Spline Figure, The Visual Computer, Vol. 3, No. 5, pp. 272-276.

....to the angles of nearby joints; this keeps the surface smooth and non interpenetrating around the joints, and simulates muscle bulging due to flexion. Gascuel extracted a spline surface around a skeleton [16] Sometimes the surface is geometrically adjusted during motion to mimic deformation [21]. Turner et al. used a deformable, elastic skin for character animation [45] A variant of this class of methods have attempted to use a pre defined skin (usually a polygonal mesh or spline surface of some type) which is embedded in some space filling function whose purpose is to deform the ....

M. Hahas, H. Huitric, and M. Saintourens. Animation of a b-spline figure. The Visual Computer, 3(4), 1987.

....facial animation. To accomplish convincing facial animations we have to pay attention to both of these objectives. Most facial animation systems are based on polygon meshes for representing the skin of the face (Aizawa 1989; Waters 1987 1990; Williams 1990, etc. Only a few systems (Waite 1989; Nahas 1988) use a B spline model instead of a polygonal model. The accuracy of the model is determined by the number of polygons used. Polygonal models are easy to handle, and the data points can be directly controlled. A disadvantage of polygonal models is the fact that additional expenditure for realistic ....

Nahas M, Huitric H, Saintourens M. (1988) Animation of a B-Spline figure, The Visual Computer 3: 272-276.

....also be analyzed. The reader can refer to parts I IV of the EAGLES handbook for more information on speech analysis. When phonemes have been identified they are associated with facial control parameters to compute the appropriate mouth shape. Linear prediction analysis [186] sound segmentation [220], HMM modeling and decoding [343] techniques have been used to generate mouth shapes. ffl Puppeteer control: A puppeteer moves input devices such as dataglove and joysticks, or uses a keyboard to drive a facial model (see Figure 11) Each input device control is associated with a facial parameter ....

....As the puppeteer moves the hand or presses different keys, the facial model moves accordingly. This technique is often used for real time application and movies. ffl Text to visual speech: The input of the system is plain text. The input text is first decomposed into its phonetic representation [148, 237, 32, 156, 220, 338]. Information about phonemes and their duration are automatically generated from the text. Formants and other speech parameters (frequency, pitch, pitch range and so on) are then computed. Text to visual speech technique is suited when parametric facial models are used. Parameters defining facial ....

[Article contains additional citation context not shown here]

M. Nahas, H. Huitric, and M. Saintourens. Animation of a B-spline figure. The Visual Computer, 3(5):272--276, March 1988.

....z and x offsets. The program made a transition between two phonemes by interpolating in a nonlinear fashion between the values for two adjacent phonemes. Different transition speeds were used depending on the type of segments involved. A B spline surface model has also been used to generate faces (Nahas, Huitric, Saintourens, 1988). To derive the control points of the B spline surface, Nahas et al. used a scanning device to obtain 3D surface slices. B spline control parameters were obtained to generate a facial shape for each phoneme. Images of these faces (held in a frame store) were then concatenated according to the ....

Nahas, M., Huitric, H., & Saintourens, M. (1988) Animation of a B-spline figure. The Visual Computer, 3, 272-276.

.... 78153 Le Chesnay, France the external and interface structures of the skin leads to a computer simulation of some plastic surgery operations [ Pieper, 1992 ] Multi layer approach [ Kalra et al. 1991 ] or addition of some speech parameters [ Hill et al. 1988 ] Lewis and Parke, 1987 ] Nahas, 1988 ] were included in animation systems to produce automatic lip synchronization. Their approach was to express the animation by a set of rules where every element (of the sound and of the face) can be modified interactively through the use of parameters. To gain higher level control over facial ....

M. Nahas, H. Huitric, and M. Saintourens. Animation of b-spline figure. The Visual Computer, 3:272-- 276, 1988.

....believableness. 6 Geometric Representations As we have described above, many facial systems use polygonal representations for the 3D model. Such representations take advantage of hardware facilities for fast rendering (e.g. hard shading) B spline techniques and its derivatives are also used [149, 94, 152, 147]. The B spline technique is often chosen for its locality property, where the change of position of a control point affects only the other points in its environment (the number of affected points depends on the order of the spline) B spline surfaces have the advantage of smoothing the created ....

....of a control point affects only the other points in its environment (the number of affected points depends on the order of the spline) B spline surfaces have the advantage of smoothing the created model. Zones of influence of a muscle are defined by B spline basis functions. In some systems [94], however, the muscle action, the propagation of muscle movement and the shape of the skeleton are not differentiated, but are reproduced by changing the position of characteristic control points. Waite [149] combines B spline surfaces for the skin with an underlying structure of facial muscles. ....

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M. Nahas, H. Huitric, and M. Saintourens. Animation of a B-spline figure. The Visual Computer, 3(5):272--276, March 1988.

....to the angles of nearby joints; this keeps the surface smooth and non interpenetrating around the joints, and simulates muscle bulging due to flexion. Gascuel extracted a spline surface around a skeleton [9] Sometimes the surface is geometrically adjusted during motion to mimic deformation [12]. Turner et al. used a deformable, elastic skin for character animation [26] A variant of this class of methods have attempted to use a pre defined skin (usually a polygon mesh or spline surface of some type) which is embedded in some space filling function whose purpose is to deform the skin ....

M. Hahas, H. Huitric, and M. Saintourens. Animation of a b-spline figure. The Visual Computer, 3(4), 1987.

....to worry about north pole difficulties or the irregularities of human topology. 4 Pentagonal patches constructed from five B ezier patches which were used at the joints in order to deal with branching structures (such as arms) in a more graceful manner. 20 Figure 2.9. Biquintic B spline faces (Nahas, Huitric, Saintourens, 1988) 2.3.2.4. Nahas, Huitric, and Saintourens. As the Komatsu model demonstrates, adding detail to one area of a continuous spline surface causes a dramatic increase in the number of patches needed in the surface. 5 Despite these possible complications, a team of researchers at the University of ....

....the Komatsu model demonstrates, adding detail to one area of a continuous spline surface causes a dramatic increase in the number of patches needed in the surface. 5 Despite these possible complications, a team of researchers at the University of Paris built a model of the face out of B splines (Nahas et al. 1988). Nahas, Huitric, and Saintourens use biquintic B splines to model head data obtained with a 3D scanner. The problem with traditional splines is that only a single level of detail can be chosen. Areas of low detail (back of the head, sides of the cheeks) are over represented, and areas of high ....

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Nahas, M., Huitric, H., & Saintourens, M. (1988). Animation of a B-spline figure. The Visual Computer, 3 (5), 272--276.

.... Blinn s seminal work on implicit surface modeling included a blobby man made by extracting a surface from around an articulated skeleton [Bli82] Gascuel extracted a spline surface around a skeleton [Gas89] Sometimes the surface is geometrically adjusted during motion to mimic deformation [HHS87] Magnenat Thalmann and Thalmann extended this idea in their joint local deformations (JDL s) where procedures are associated with each joint to simulate natural changes [MTT91] Singh et al. presented an approach using implicit surfaces [SOP95] Chadwick, Haumann, and Parent presented a method ....

M. Hahas, H. Huitric, and M. Saintourens. Animation of a b-spline figure. The Visual Computer, 3(4), 1987.

.... 1 Introduction Over the last score years, many researchers attempted to control the animation of synthetic faces so that they could speak with more or less natural lip gestures ( BQ83] LP87] STHN90] PBS91] PWWH86] MTET88] MAH90] CM93] However, the models used ( Par82] Par91] PB81] NHS88] were not primarily designed to account for the natural gestures of human lips speaking. As an example, Cohen and Massaro [CM90] had to introduce several extra parameters to that first identified by Parke [Par82] in order for their speaking head to produce most of lip gestures in English. At the ....

M. Nahas, Huitric H., and M. Saintourens. Animation of a b-spline figure. Visual Computer, 3:272--276, 1988.

....A living face (human or animal) in motion is a complex animated structure in which fine details, rigid and deformable structures run together producing a variety of expressions. The choice of a specific facial model is dictated by the particular effects one expects to achieve during animation. See [72, 105, 103, 98, 138, 119, 81, 101, 89, 66, 124, 144, 133, 146, 134, 148, 80, 75, 108, 28]. As discussed above, all human faces possess the same physiological organization of bones, muscles and skin. People smile in the same way contracting the big zygomatic and the lips corner elevator. Nevertheless, all faces are different. The complexity of facial animation is due mainly to the ....

....Furthermore, cutting surface parts may be easily achieved due to the local nature of simplex meshes: muscles attached to both skin and skull adjust the shape to the reconstructed skull. Splines For very smooth surface, a variety of spline based surface patch methods can be used. ffl B splines: [98] The face is modeled using B splines. Deformations are performed by moving groups of controls points. ffl Cardinal splines springs: 138] A cardinal spline representation is coupled with a spring network. Muscle deformations are generated by applying forces to the spring network. For each rest ....

M. Nahas, H. Huitric, and M. Saintourens. Animation of a B-spline figure. The Visual Computer, 3(5):272--276, March 1988.

.... tissue with dynamic simulation of muscle movements, considerable realism in creating subtle facial actions may be achieved [Terzopoulos and Waters, 1991] Automatic lip synchronization is included into animation systems by a multi layer approach [Kalra et al. 1991] or by adding speech parameters [Nahas et al. 1988], Hill et al. 1988] A correspondence between each speech unit and a basic lip shape is established. Of particular relevance is the model of coarticulation proposed by [Cohen and Massaro, 1993] It uses overlapping dominance functions. These functions specify for each viseme how close the lips ....

....live animation [Williams, 1990] Terzopoulos and Waters, 1991] Essa and Pentland, 1994] The computed movement information is interpreted as muscle contractions and is given as input to the animation system. Texture mapping is used to enhance the realism of features and skin tone of the model [Nahas et al. 1988], Williams, 1990] Kurihara and Arai, 1991] The consideration of wrinkles and of aging effects [Viaud and Yahia, 1992] adds much to the rendering of facial skin and expressions. 1.1 The Approach Our main goal is to look at coordinated motion during a conversation. To do so, we need to ....

Nahas, M., Huitric, H., and Saintourens, M. (1988). Animation of b-spline figures. The Visual Computer, 3:272--276.

....traditional splines is that only a single level of detail can be chosen. Areas of low detail (back of the head, sides of the cheeks) are over represented, and areas of high detail may not have the required amount of curvature (thus in their 1988 model there are no nostrils and the lips look blurry[6]) Texture maps conceal some of these sins and introduce others of their own. y Emphasis was applied by this author. 4 CAROL LEON YUN WANG 9. Puppetry and Performance deGraf Wahrman have a model made from 2000 polygons. When Mike Normal speaks, the phonemes that it can utter were each ....

M. Nahas, H. Huitric, and M. Saintourens, Animation of a B-spline figure, The Visual Computer 3 (1988), no. 5, 272--276.

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M. Nahas, H. Huitric, and M. Saintourens. Animation of a B-Spline figure. The Visual Computer, (3):272--276, 1988.

No context found.

M. Nahas, H. Huitric, and M. Saintourens. Animation of a B-Spline Figure. The Visual Computer, 3(5):272--276, March 1988.

No context found.

M. Nahas, H. Huitric, and M. Saintourens. Animation of a B-Spline Figure. The Visual Computer, 3(5):272--276, March 1988.

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