PATENT ABSTRACT
The device comprising an arm joint wrinkle simulator, wherein when the arm joint angle value represents a first angle value, a first wrinkle image of the fabric covering the arm joint is generated on or near the arm joint, when the arm joint angle value represents a second angle value, a second wrinkle image of the fabric covering the arm joint is generated on or near the arm joint, and when the arm joint angle value represents a third angle value, the fabric covering the arm joint with no wrinkle image is generated on or near the arm joint.

PATENT DESCRIPTION
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 13/165,820 filed on 2011 Jun. 22, which is a continuation of U.S. Ser. No. 12/016,999 filed on 2008 Jan. 19, now U.S. Pat. No. 7,983,882, which is a continuation of U.S. Ser. No. 10/065,923 filed on 2002 Nov. 30, now U.S. Pat. No. 7,386,429, which claims the benefit of U.S. Provisional Application No. 60/337,949, filed 2001 Dec. 7, all of which are hereby incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF INVENTION 
     The invention relates to a simulation software and more particularly to a simulation software which displays human beings on monitors, LCDs, screens, and other display means in a realistic fashion. 
     Lately simulation software is being used in video games, military training devices, and other types of devices which implement virtual reality. These devices are designed to display various types of objects which exist in the real world, however, the movement of a human being displayed thereon gives a sense of awkwardness to the users thereof since these devices do not reflect the movement of a human being in the real world in a precise manner. One reason which gives such sense of awkwardness is that the clothe worn by a human being does not wrinkle at all when he/she bends his/her limbs.  FIG. 1   a  and  FIG. 1   b  illustrate the method of displaying an arm of a human being by utilizing the prior art. As described in  FIG. 1   a , arm AR of a human being is composed of hand HD, lower arm LA, joint JT, and upper arm UA. Assuming that arm UA is covered by fabric FB, i.e., the human being is wearing a clothe which covers his/her arms. When arm AR is stretched as described in  FIG. 1   a  and joint JT is not bent, wrinkle does not occur on or near joint JT. When arm AR is bent as described in  FIG. 1   b , however, due to the nature of fabric FB one or more of wrinkles occur on or near joint JT in the real world. Prior art has not yet described the movement of limbs in such a way thereby gives a sense of awkwardness to the users since no wrinkles are shown. Another reason which gives a sense of awkwardness to the users is that the prior art has ignored to display the muscle movement of the limbs of the human beings. When arm AR is bent as described in  FIG. 1   b , the muscles of upper arm UA bulge in the real world, however, the prior art has not yet described the muscle movement in such a way. 
     U.S. Pat. No. 6,317,125 introduces a video object generation method (100) for converting a model (102) such that a tessellation operation (164) can create a realistic character in real time during game play. According to this prior art, a shelling and slicing operation (106) produces data strings (140) describing a plurality of slices (110) of the model (102). An assign body parts and edit strings operation (130) places cuts (134) on the model (102) and an apply influences operation (144) establishes the influence on each of a plurality of points (142) from a plurality of bones (148) of a skeleton (146). In real time operations (162) a tessellation operation (164) creates a triangle mesh (165) appropriate to the position and importance of the character in game space, and a properly bent character is displayed in a display operation (168). This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,317,130 introduces apparatus and method to enable an animation character object, which is pictorially deformed by computer graphics techniques to visually represent human body or animal or the like in the form of a caricature or model, to offer precise and more natural motions at its selected constituent portions that have inherently no joints and no bones by giving thereto joints and skeletons. According to this prior art, apparatus and method for generating skeleton-based animation images in accordance with the principles of the invention include solving means as follows. A face section of a cubic character object is provided with auxiliary skeletons as vertically coupled together. Skeletons are provided which extend from respective endpoints of such auxiliary skeletons and are coupled defining an umbrella shape as a whole. These skeletons are associated with models each consisting of an ensemble of polygons for rendering the character deformable by changing rotation amount of each skeleton. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,310,619 introduces a three-dimensional, virtual reality, tissue specific model of a human or animal body which provides a high level of user-interactivity. According to this prior art, the model functions can be analyzed and user-modified on a tissue-by-tissue basis, thereby allowing modeling of a wide variety of normal and abnormal tissue attributes and corresponding study thereof. The model can be user-modified through a keyboard, or other VR tools such as a haptic interface. The haptic interface can modify the model to correspond to the tissue attributes of a user, and can provide sensory output corresponding to the interaction of the model to a prescripted scene. A three-dimensional, virtual reality, tissue specific model of a human or animal body which provides a high level of user-interactivity. The model functions can be analyzed and user-modified on a tissue-by-tissue basis, thereby allowing modeling of a wide variety of normal and abnormal tissue attributes and corresponding study thereof. The model can be user-modified through a keyboard, or other VR tools such as a haptic interface. The haptic interface can modify the model to correspond to the tissue attributes of a user, and can provide sensory output corresponding to the interaction of the model to a prescripted scene. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 5,625,577 introduces a motion analyzing method which analyzes and displays motions of a human being or an animal using a computer in an interactive manner without requiring trial and error or without depending on intuition of an analyst. According to this prior art, a human body or an animal body is divided into a plurality of segments connected by joints, each of the segments acting as a minimal unit of motion. Data for modeling the human or animal body on the basis of physical constraints and the inherent nature of each of the segments is maintained in a database. Motions are input to be analyzed and the input motions are analyzed using inverse dynamics. The resultant movements and the center of gravity of each of the segments, the force and torque exerted on each of the joints, the movement and the center of gravity of the whole body, and the forces and torques exerted on the centers of gravity are superimposed on the human or animal body model of the database and are displayed on a screen. The new motions thus displayed can be used for the teaching of new skills in the industrial or performing arts, in sports, or in animal training. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,215,500 introduces methods and systems for compressing and decompressing 3-D geometry data which includes regularly tiled surface portions. According to this prior art, one compression method includes representing a surface portion as a “vertex raster”, which comprises specifying an extent value and encoding the vertex parameter values of vertices within the surface portion. The extent of the surface portion specifies the arrangement of vertices within the surface portion, and allows the vertices to be properly assembled into drawing primitives during decompression. The encoded vertex parameter values may be encoded globally (by setting initial values and corresponding delta values), locally (on a per-vertex basis), or using a combination of these techniques. Absolute, delta encoding, or delta-delta encoding may be utilized for these parameter values. Vertex parameters which may be encoded in this manner include position, color, normals, z-displacement values, texture map coordinates, and surface material properties. Additionally, connectivity information may also be encoded using this compression method by specifying quad split bits and half-resolution edges. Quad split bits are used to tessellate a quadrilateral formed by neighboring vertices of a surface portion according to the direction of the strongest color change. Half-resolution edges are utilized to gradually shift from an area of high resolution to an adjacent surface portion represented in lower resolution. For graphical objects which include a plurality of adjacent surface portions, a step command is disclosed which allows data from one surface portion to be advantageously reused. Decompression of a vertex raster representation may comprise decoding the extent value, global parameter values, and a per-vertex stream of local parameter values. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,204,860 introduces a system that defines a wire curve deformation primitive with a free-form parametric curve associated with the closest points to the curve on a surface of a model. According to this prior art, the wire curve includes a radius influence defining the points on the object which will be deformed. A scale factor determines the amplitude of the scaling or point movement that is caused by the wire curve. A blending function of the wire curve defines the transition form deformed regions of the object to undeformed regions of the object. The wire curve can have associated with it holder curves defining the domain of deformation about an object caused by one or more wires. A holder curve holds the points of the object in place. Locators are used to define different parameters values along the wire curve. Changes in parameter values around the locators are accomplished by interpolation. Deforming includes preprocessing steps as well as deformation stage operations. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,144,385 introduces a character animation system executing on a computer. According to this prior art, the system provides a simple, efficient and powerful user interface that allows the user to specify complex animations of multi-legged characters by placing footprints on a surface. A compiler automatically generates a natural looking animation based on the footprints. Motions such as walking, running, jumping, etc. are easily animated depending on the way footprints are placed. The user is able to create new footprint patterns and modify existing patterns. Footprint blocks on a timeline are used to specify the time duration that each foot is in contact with a footprint. The user may specify keyframes in the animation sequence that allow more complicated body movements to be incorporated with the footprint based animation. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,088,034 introduces a method and apparatus wherein three-dimensional compressed geometry is decompressed with a unit having an input FIFO receiving compressed data bits and outputting to an input block state machine and an input block, whose outputs are coupled to a barrel shifter unit. According to this prior art, input block output also is input to Huffman tables that output to the state machine. The state machine output also is coupled to a data path controller whose output is coupled to a tag decoder, and to a normal processor receiving output from the barrel shifter unit. The decompressor unit also includes a position/color processor that receives output from the barrel shifter unit. Outputs from the normal processor and position/color processor are multiplexed to a format converter. For instructions in the data stream that generate output to the format converter, the decompression unit generates a tag sent to the tag decoder in parallel with bits for normals that are sent to the format converter. The decompressed stream of triangle data may then be passed to a traditional rendering pipeline, where it can be processed in full floating point accuracy, and thereafter displayed or otherwise used. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,064,390 introduces an apparatus and method for representing expression in a tissue-like system that may include a human face, where the system is particularized to a specified individual. According to this prior art, a graphical representation generator implemented in a computer determines a representation, in terms of a finite-element model, of the surface of the tissue of the system, providing a graphic output defining the surface in world coordinates. An expressive detail generator, including a wrinkle generator, modifies the surface determined by the graphical representation generator before the surface has been mapped into world coordinates in accordance with three-dimensional features of the tissue-like system of a particular subject. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 5,850,222 introduces a computer system for displaying clothing on a rendered image of a human body referred to as a virtual dressing room system (“VDRS”). According to this prior art, the VDRS receives a series of contour lines defining the three-dimensional shape of the human body. A contour line is a series of points that defines the perimeter of the body in a horizontal plane. The VDRS also receives a sequence of points defining the two-dimensional shape of the clothing. The VDRS also scales the sequence of points defining the two-dimensional shape of the clothing to the approximate width of a portion of the human body over which the clothing is worn. For each point of the two-dimensional shape, the VDRS identifies a corresponding point on a contour line, and adjusts the point of the two-dimensional shape of the clothing to correspond to the identified point. The VDRS renders the shape of the human body on a display device, and lenders the scaled and adjusted two-dimensional shape of the clothing on the display device to effect the display of the human body wearing the clothing. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 5,802,220 introduces a system which tracks human head and facial features over time by analyzing a sequence of images. According to this prior art, the system provides descriptions of motion of both head and facial features between two image frames. These descriptions of motion are further analyzed by the system to recognize facial movement and expression. The system analyzes motion between two images using parameterized models of image motion. Initially, a first image in a sequence of images is segmented into a face region and a plurality of facial feature regions. A planar model is used to recover motion parameters that estimate motion between the segmented face region in the first image and a second image in the sequence of images. The second image is warped or shifted back towards the first image using the estimated motion parameters of the planar model, in order to model the facial features relative to the first image. An affine model and an affine model with curvature are used to recover motion parameters that estimate the image motion between the segmented facial feature regions and the warped second image. The recovered motion parameters of the facial feature regions represent the relative motions of the facial features between the first image and the warped image. The face region in the second image is tracked using the recovered motion parameters of the face region. The facial feature regions in the second image are tracked using both the recovered motion parameters for the face region and the motion parameters for the facial feature regions. The parameters describing the motion of the face and facial features are filtered to derive mid-level predicates that define facial gestures occurring between the two images. These mid-level predicates are evaluated over time to determine facial expression and gestures occurring in the image sequence. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 5,687,737 introduces an optimal electrophysiologic mapping system for map-directed arrhythmia surgery and cardiac research allows rapid and accurate interpretation of cardiac activation sequences. According to this prior art, the system can display activation or potential distribution data on an anatomically accurate 3-D model of the heart and allows fast, interactive control of viewing characteristics, including control of which cardiac surfaces are displayed, control of virtual lighting, rotational control of the displayed image, etc. The system employs two computer programs, GETPIC3 and MAP3, and runs on a Silicon Graphics workstation capable of rapid graphics calculations and displays. The system utilizes 3-D models of epicardial and endocardial surfaces created with the GETPIC3 program from a sequence of 2-D images of a heart. The individual surfaces are triangulated and may be smoothed using a spline function. The MAP3 program displays activation times either as static isochronous maps or as dynamic time-since-last-activation maps. In the latter case, surface color denotes the time elapsed since a particular area activated. Potential distribution data may also be displayed dynamically. A mouse allows the system operator to control real-time rotation of the model in three dimensions, and any surface can be hidden interactively for better viewing of the data. Control is also provided over the starting, stopping, reversing, and repeating of data, as well as over the frame rate for dynamic displays. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 5,504,845 introduces a three dimensional image of a solid form which is presented to an operator by means of a stereoscopic display. According to this prior art, the operator defines a panel on the surface of the form with a set of bounding seam lines. A polygonal mesh is generated between the seam lines and is manipulated in three dimensions by the operator to achieve a desired surface appearance, including wrinkles, folds, pleats and other details. Manipulation of the mesh is constrained by the mechanical properties of the surface material or fabric being modelled. Surface texture and shading are then mapped onto the mesh to fully render the surface appearance in three dimensions. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 5,267,154 introduces a biological image formation aiding system and a biological image forming method which are provided in which three-dimensional data corresponding to a standard shape of a biological article, standard motion thereof, and a standard material feeling of an outer surface of the biological article are prepared, and a realistic three-dimensional synthesized image of an entire biological article with individuality can be formed simply. According to this prior art, the system includes a shape data storage for storing data corresponding to a three-dimensional shape of a biological image; a motion data storage for storing data corresponding to three-dimensional motion of the biological image, a material feeling data storage for storing data corresponding to a three-dimensional material feeling of an outer surface of the biological image; editing/processing units capable of modifying at least one of the data corresponding to the three-dimensional shape of the biological image, the three-dimensional data corresponding to the motion of the biological image, and the data corresponding to the three-dimensional material feeling of the outer surface of the biological image in accordance with a producer&#39;s intent; and an output unit responsive to the outputs of the editing/processing unit for synthesizing the data corresponding to the three-dimensional biological image, the data corresponding to the three-dimensional motion of the biological image, and the data corresponding to the three-dimensional material feeling of the outer surface of the biological image after modification with each other to provide synthesized three-dimensional data for a biological image to be produced. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,326,967 introduces an image creating apparatus which displays a plurality of identical game-element images in predetermined colors on an image display unit by pasting textures on polygons provided in a virtual three-dimensional space. According to this prior art, the image creating apparatus includes a polygon-data storage unit for storing the coordinates of N (integer not less than 2) sets of polygons constituting the element images so that N game elements are arranged and displayed on the display unit; a texture-selection-data storage unit for selecting one set of the textures which corresponds to one of the characters; a color-data storage unit for storing, as a basic color, a first color determined for the one set of the textures; a color-data setting unit for setting a second color; and a composite-color setting unit for setting composite colors for the textures to be pasted on N sets of polygons, the composite colors being obtained by mixing the first color and the second color at different ratios. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,322,448 introduces a image processing device for games which is a device whereby a prescribed number of models (characters) are set up in virtual space, these models are controlled such that they move in prescribed directions in the virtual space, and images of this virtual space from a virtual viewpoint are displayed on means for display. According to this prior art, in order to display the movement of the models that are arranged in virtual space more realistically, in one construction thereof, this device is provided with means for image processing that apply virtual centripetal force to the models. Furthermore, in order to display the movement of the models more realistically and to heighten the dramatic effect, in one construction thereof, this device is equipped with means for processing residual image presentation in order to represent the track of movement of a model as residual images. This means for processing is equipped with means for storage that store without modification motion data of the model prior to the current motion and with means for display control that display this stored data together with the current motion data. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     U.S. Pat. No. 6,320,988 introduces a method of transforming the shape of a skeleton model, wherein this method can easily handle a skeleton model of a multiple-branching structure and enables the easy setting of complicated restrictive conditions. According to this prior art, node coordinates and arc-normal vectors are used as basic variables. Basic equations, which comprise an equation defining the length of an arc and which use basic variables as unknowns, and an evaluation expression for uniquely specifying a solution that satisfies these basic equations are modified, based on data such as mouse input. A solution for the basic variables that satisfies the basic equations and minimizes the value of the evaluation expression is obtained, and the shape of the skeleton model is transformed accordingly. The evaluation expression is used to set minimization of the sum-of-squares of arc-to-arc angles, rubber-banding, dampers, and inertia. The basic equations and the evaluation expression are updated in synchronization with the end of a loop. A spring restriction can be set, and the use of a restrictive condition in the next loop of the calculations can be determined from whether or not the restrictive condition was used in the previous loop, and whether or not an object has passed a boundary. This prior art introduces the concept of producing realistic images, however, does not explain nor imply the present invention, i.e., the method to simulate the upper arm of a human being in a realistic manner. 
     SUMMARY OF INVENTION 
     It is an object of the present invention to provide the method to simulate the upper arm of a human being in a realistic manner. 
     Still another object is to overcome the aforementioned shortcomings associated with the prior art. 
     Further objects, features, and advantages of the present invention over the prior art will become apparent from the detailed description which follows, when considered with the attached figures. 
     The present invention introduces a simulation software capable of displaying a human being comprising a plurality of limbs, each of said plurality of limbs comprises a first part and a second part and is also capable of displaying one or more of wrinkles on or near the joint of said first part and the second part wherein said first part and said second part is connected, the angle produced by said first part and said second part is variable, and the more the value of said angle decreases the more the amount and/or the height of said wrinkles increases thereby enabling said simulation software to display the movement of said human being and the movement of said first and said second part in a realistic manner. 
     The present invention further introduces a simulation software capable of displaying a human being comprising of a plurality of limbs and each of said plurality of limbs comprises a first part and a second part wherein said first part and said second part is connected, the angle produced by said first part and said second part is variable, and the more the value of said angle decreases the more the thickness of said first part increases thereby enabling said simulation software to display the movement of said human being and the movement of said first and said second part in a realistic manner. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other aspects, features, and advantages of the invention will be better understood by reading the following more particular description of the invention, presented in conjunction with the following drawings, wherein: 
         FIG. 1   a  is a simplified illustration illustrating the method to display the arm of a human being by utilizing the prior art. 
         FIG. 1   b  is a simplified illustration illustrating the method to display the arm of a human being by utilizing the prior art. 
         FIG. 2  is a block diagram illustration of the computer which performs the present invention. 
         FIG. 3  is a simplified illustration of the area included in the RAM. 
         FIG. 4  is a simplified illustration illustrating the concept of the present invention. 
         FIG. 5  is a simplified illustration illustrating one method of generating wrinkles. 
         FIG. 6  is a simplified illustration illustrating another method of generating wrinkles. 
         FIG. 7  is a simplified illustration of the area included in the RAM. 
         FIG. 8  is a simplified illustration of the content included in the RAM illustrated in  FIG. 7 . 
         FIG. 9   a  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 9   b  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 9   c  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 9   d  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 9   e  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 10  is a simplified illustration of the area included in the RAM. 
         FIG. 11  is a flowchart illustrating the operation of the wrinkle generating software. 
         FIG. 12   a  is a simplified illustration of an exemplary embodiment to produce wrinkles. 
         FIG. 12   b  is a simplified illustration of an exemplary embodiment to produce wrinkles. 
         FIG. 12   c  is a simplified illustration of an exemplary embodiment to produce wrinkles. 
         FIG. 12   d  is a simplified illustration of an exemplary embodiment to produce wrinkles. 
         FIG. 13  is a simplified illustration of the area included in the RAM. 
         FIG. 14  is a simplified illustration of the content included in the RAM illustrated in  FIG. 13 . 
         FIG. 15   a  is a simplified illustration of the method to display a wrinkle on the monitor. 
         FIG. 15   b  is a simplified illustration of the method to display a wrinkle on the monitor. 
         FIG. 15   c  is a simplified illustration of the method to display a wrinkle on the monitor. 
         FIG. 15   d  is a simplified illustration of the method to display a wrinkle on the monitor. 
         FIG. 15   e  is a simplified illustration of the method to display a wrinkle on the monitor. 
         FIG. 16  is a simplified illustration of the area included in the RAM. 
         FIG. 17  is a flowchart illustrating the operation of the wrinkle generating software. 
         FIG. 18   a  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 18   b  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 18   c  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 18   d  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 18   e  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 19  is a simplified illustration of the area included in the RAM. 
         FIG. 20  is a simplified illustration of the content included in the RAM illustrated in  FIG. 20 . 
         FIG. 21   a  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 21   b  is a simplified illustration of the method to display wrinkles on the monitor. 
         FIG. 21   c  is a simplified illustration of the method to display wrinkles on the monitor. 
         FIG. 21   d  is a simplified illustration of the method to display wrinkles on the monitor. 
         FIG. 21   e  is a simplified illustration of the method to display wrinkles on the monitor. 
         FIG. 22  is a simplified illustration of the area included in the RAM. 
         FIG. 23  is a flowchart illustrating the operation of the wrinkle generating software. 
         FIG. 24   a  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 24   b  is a simplified illustration of the method to display wrinkles on the monitor. 
         FIG. 24   c  is a simplified illustration of the method to display wrinkles on the monitor. 
         FIG. 24   d  is a simplified illustration of the method to display wrinkles on the monitor. 
         FIG. 24   e  is a simplified illustration of the method to display wrinkles on the monitor. 
         FIG. 25  is a simplified illustration of the area included in the RAM. 
         FIG. 26  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 27  is a simplified illustration of the method to display muscle movement. 
         FIG. 28  is a simplified illustration of the area included in the RAM. 
         FIG. 29  is a simplified illustration of the data stored in the RAM. 
         FIG. 30   a  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 30   b  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 30   c  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 30   d  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 30   e  is a simplified illustration of the method to display the arm on the monitor. 
         FIG. 31  is a flowchart illustration of illustrating the operation of the muscle movement generating software. 
         FIG. 32   a  is a simplified illustration of the method to display the muscle movement on the monitor. 
         FIG. 32   b  is a simplified illustration of the method to display the muscle movement on the monitor. 
         FIG. 32   c  is a simplified illustration of the method to display the muscle movement on the monitor. 
         FIG. 32   d  is a simplified illustration of the method to display the muscle movement on the monitor. 
         FIG. 32   e  is a simplified illustration of the method to display the muscle movement on the monitor. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is of the best presently contemplated mode of carrying out the present invention. This description is not to be taken in a limiting sense but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined by referencing the appended claims. 
       FIG. 2  illustrates the details of computer  200  which performs the present invention. CPU  211  controls and administers the overall function and operation of computer  200 . CPU  211  uses RAM  206  to temporarily store data and/or to perform calculation to perform its function. Video generator  202  generates analog and/or digital video signals which are displayed on monitor  201 . Sound generator  205  generates analog and/or digital video signals which are transferred to speaker  204 . HDD  207  stores data and/or programs which are necessary to perform the present invention. Interface  208  is an interface between computer  200  and a server which enables computer  200  to send and receive digital data with the server. Input signals are input by input device  210 , such as keyboard and joystick, and the signals are transferred via input interface  209  and data bus  203  to CPU  211 . Computer  200  can have the same or a similar structure to the computers which are described in FIG. 1 of the U.S. Pat. No. 5,870,101, FIG. 2 of the U.S. Pat. No. 6,157,384, FIG. 1 of the U.S. Pat. No. 5,774,125, FIG. 1 of the U.S. Pat. No. 5,375,206, and/or FIG. 1 of the U.S. Pat. No. 5,925,127. Overall, computer  200  has the capability of displaying three-dimensional objects on monitor  201  by utilizing the texture mapping method or only by polygons. Video Generator  202  takes the major role in displaying the three-dimensional objects. 
     As illustrated in  FIG. 3 , RAM  206  ( FIG. 2 ) includes area  301 . Area  301  stores a wrinkle generating software which is designated to generate wrinkles as described in details hereinafter. 
       FIG. 4  illustrates the concept of the present invention. As described in  FIG. 4 , arm AR of an object (human being) consists of hand HD, lower arm LA, joint JT, and upper arm UA. Assuming that arm UA is covered by fabric FB, i.e., the object is wearing a suit of clothes which covers his/her arms. When arm AR is bent, wrinkles  400  is generated on or near joint JT by the wrinkle generating software stored in area  301  ( FIG. 3 ) of RAM  206  ( FIG. 2 ). 
       FIG. 5  illustrates the method of generating wrinkles. The most convenient way to generate wrinkles is to paste a texture describing wrinkles on a piece of polygon by the method so-called the “texture mapping.” The details of such method are explained in the patents described hereinbefore. The method of “texture mapping” is not explained in this patent specification in details since such method itself is not the object of the present invention. As illustrated in  FIG. 5 , texture  501  which is applied on or near joint JT ( FIG. 4 ) has a pattern consisting of a plurality of plateaus and valleys. Plateaus  502 ,  519 , and  505  represent the highest portion of the wrinkles displayed and valley  503  and  504  represent the space between the wrinkles. For purposes of designing texture  501 , plateaus  502 ,  519 , and  505  are displayed with lighter colors, and valley  503  and  504  are displayed with darker colors compared to these plateaus. 
       FIG. 6  illustrates another method of generating wrinkles. A plurality of polygons in this embodiment are used to generate wrinkles. Namely polygons P 1  and P 2 , P 3  and P 4 , P 5  and P 6  represent wrinkle respectively. More precisely the connected portion of polygons P 1  and P 2  represents plateau  502 , the connected portion of polygons P 2  and P 3  represents valley  503 , the connected portion of polygons P 3  and P 4  represents plateau  519 , the connected portion of polygons P 4  and P 5  represents valley  504 , and the connected portion of polygons P 5  and P 6  represents plateau  505  in  FIG. 5 . 
       FIG. 7  through  FIG. 12   d  illustrate the method of determining the amount of wrinkles that should be displayed on monitor  201  ( FIG. 2 ). 
     As illustrated in  FIG. 7 , RAM  206  ( FIG. 2 ) includes area  302 . Area  302  stores a plurality of data which are necessary to produce a plurality of wrinkles. 
       FIG. 8  illustrates the content of area  302  ( FIG. 7 ) of RAM  206  ( FIG. 2 ). Area  302  includes two types of data, i.e., the data representing the angle of joint JT ( FIG. 4 ) produced by upper arm UA ( FIG. 4 ) and lower arm LA ( FIG. 4 ), and the data representing the amount of wrinkles displayed. In the example described in  FIG. 8 , the amount of wrinkles displayed is 0 when the angle of joint JT produced by upper arm UA and lower arm LA is 180 degrees. However, the amount of the wrinkles increases as the angle of joint JT produced by upper arm UA and lower arm LA decreases. In the present example, the amount of wrinkle displayed is 1 when the angle is less than 180 degrees and 160 degrees or more; the amount of wrinkles displayed is 2 when the angle is less than 160 degrees and 135 degrees or more; the amount of wrinkles displayed is 3 when the angle is less than 135 degrees and 110 degrees or more; and the amount of wrinkles displayed is 4 when the angle is less than 110 degrees and 20 degrees or more. 
       FIG. 9   a  through  FIG. 9   e  illustrate how arm AR is displayed on monitor  201  ( FIG. 2 ) in accordance with the data stored in area  302  ( FIG. 7 ) of RAM  206  ( FIG. 2 ). Assuming that arm AR is covered with fabric FB. When arm AR is stretched as described in  FIG. 9   a  and the angle of joint JT ( FIG. 4 ) produced by lower arm LA and upper arm UA is 180 degrees, no wrinkles are shown on or near joint JT. As described in  FIG. 9   b , when arm AR is slightly bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 180 degrees and 160 degrees or more one wrinkle, i.e., wrinkle  401  is displayed on or near joint JT. As described in  FIG. 9   c , when arm AR is further bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 160 degrees and 135 degrees or more, two wrinkles, i.e., wrinkles  401  and  402  are displayed on or near joint JT. As described in  FIG. 9   d , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 135 degrees and 110 degrees or more, three wrinkles, i.e., wrinkles  401 ,  402 , and  403  are displayed on or near joint JT. As described in  FIG. 9   e , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 110 degrees and 20 degrees or more, four wrinkles, i.e., wrinkles  401 ,  402 ,  403  and  404  are displayed on or near joint JT. 
       FIG. 10  illustrates a plurality of texture utilized to display wrinkles on monitor  201  ( FIG. 2 ). As illustrated in  FIG. 10 , RAM  206  ( FIG. 2 ) includes area  303 . Area  303  stores a plurality of textures which are pasted on polygons, i.e., textures Tx  506 , Tx  507 , Tx  508 , and Tx  509 . Tx  506  includes one wrinkle, i.e., wrinkle  401  illustrated in  FIG. 9   b ; Tx  507  includes two wrinkles, i.e., wrinkles  401  and  402  illustrated in  FIG. 9   c ; Tx  508  includes three wrinkles, i.e., wrinkles  401 ,  402 , and  403  illustrated in  FIG. 9   d ; and Tx  509  includes four wrinkles, i.e., wrinkles  401 ,  402 ,  403 , and  404  illustrated in  FIG. 9   e.    
       FIG. 11  illustrates the operation of the wrinkle generating software stored in area  301  ( FIG. 3 ) of RAM  206  ( FIG. 2 ). First of all, CPU  211  ( FIG. 2 ) calculates the angle of joint JT produced by lower arm LA and upper arm UA. If the angle is 180 degrees (S 1   a ), CPU  211  does not access area  303  ( FIG. 10 ) of RAM  206  (S 2   a ). If the angle is less than 180 degrees and 160 degrees or more (S 1   b ), CPU  211  retrieves Tx  506  from area  303  of RAM  206  (S 2   b ). In the same manner, if the angle is less than 160 degrees and 135 degrees or more (S 1   c ), CPU  211  retrieves Tx  507  from area  303  of RAM  206  (S 2   c ); if the angle is less than 135 degrees and 110 degrees or more (S 1   d ), CPU  211  retrieves Tx  508  from area  303  of RAM  206  (S 2   d ); and if the angle is less than 110 degrees and 20 degrees or more (S 1   e ), CPU  211  retrieves Tx  509  from area  303  of RAM  206  (S 2   e ). 
     Instead of pasting textures to polygons in order to display wrinkles, a plurality of polygons may be used to produce wrinkles as described in  FIG. 12   a  through  FIG. 12   d . One wrinkle can be produced by one set of two polygons, i.e., P 7  and P 8  as described in  FIG. 12   a . Two wrinkles can be produced by two sets of two polygons, i.e., P 7  and P 8 , and P 9  and P 10  as described in  FIG. 12   b . Three wrinkles can be produced by three sets of two polygons, i.e., P 7  and P 8 , P 9  and P 10 , and P 11  and P 12  as described in  FIG. 12   c . Four wrinkles can be produced by four sets of two polygons, i.e., P 7  and P 8 , P 9  and P 10 , P 11  and P 12 , and P 13  and P 14  as described in  FIG. 12   d . The operation of the wrinkle generating software stored in area  301  ( FIG. 3 ) of RAM  206  ( FIG. 2 ) in this embodiment is similar to the one described in  FIG. 11 . Such operation is not shown in the drawings. First of all, CPU  211  ( FIG. 2 ) calculates the angle of joint JT produced by lower arm LA and upper arm UA. If the angle is 180 degrees CPU  211  does not produce any wrinkles by polygons. If the angle is less than 180 degrees and 160 degrees or more, CPU  211  produces polygons P 7  and P 8  to display one wrinkle as illustrated in  FIG. 12   a . In the same manner, if the angle is less than 160 degrees and 135 degrees or more, CPU  211  produces polygons P 7 , P 8 , P 9 , and P 10  to display two wrinkles as illustrated in  FIG. 12   b ; if the angle is less than 135 degrees and 110 degrees or more, CPU  211  produces polygons P 7 , P 8 , P 9 , P 10 , P 11 , and P 12  to display three wrinkles as illustrated in  FIG. 12   c ; and if the angle is less than 110 degrees and 20 degrees or more, CPU  211  produces polygons P 7 , P 8 , P 9 , P 10 , P 11 , P 12 , P 13 , and P 14  to display four wrinkles as illustrated in  FIG. 12   d.    
       FIG. 13  through  FIG. 18   d  illustrate the method of determining the height of the wrinkles that should be displayed on monitor  201  ( FIG. 2 ). 
     As illustrated in  FIG. 13 , RAM  206  ( FIG. 2 ) includes area  304 . Area  304  stores a plurality of data which are necessary to determine the height of the wrinkles. 
       FIG. 14  illustrates the content of area  304  ( FIG. 13 ) of RAM  206  ( FIG. 2 ). As illustrated in  FIG. 14 , area  304  includes two types of data, i.e., the data representing the angle of joint JT ( FIG. 4 ) produced by upper arm UA ( FIG. 4 ) and lower arm LA ( FIG. 4 ), and the data representing the height of wrinkles displayed. For example, the height of the wrinkle displayed is 0 when the angle of joint JT produced by upper arm UA and lower arm LA is 180 degrees. However, the height of the wrinkle increases as the angle of joint JT produced by upper arm UA and lower arm LA decreases. In the example explained in  FIG. 14 , the height of the wrinkle displayed is 1 when the angle is less than 180 degrees and 160 degrees or more; the height of the wrinkle displayed is 2 when the angle is less than 160 degrees and 135 degrees or more; the height of the wrinkle displayed is 3 when the angle is less than 135 degrees and 110 degrees or more; and the height of the wrinkle displayed is 4 when the angle is less than 110 degrees and 20 degrees or more. 
       FIG. 15   a  through  FIG. 15   e  illustrate how arm AR is displayed on monitor  201  ( FIG. 2 ) in accordance with the data stored in area  304  ( FIG. 14 ) of RAM  206  ( FIG. 13 ). Assuming that arm AR is covered with fabric FB. When arm AR is stretched as described in  FIG. 15   a  and the angle of joint JT produced by lower arm LA and upper arm UA is 180 degrees, no wrinkles are shown on or near joint JT. As illustrated in  FIG. 15   b , when arm AR is slightly bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 180 degrees and 160 degrees or more, a small wrinkle, i.e., wrinkle  410  is displayed on monitor  201 . As illustrated in  FIG. 15   c , when arm AR is further bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 160 degrees and 135 degrees or more, a wrinkle larger than the one described in  FIG. 15   b  is displayed on monitor  201 . As illustrated in  FIG. 15   d , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 135 degrees and 110 degrees or more, a wrinkle larger than the one described in  FIG. 15   c  is displayed on monitor  201 . As illustrated in  FIG. 15   e , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 110 degrees and 20 degrees or more, a wrinkle larger than the one described in  FIG. 15   d  is displayed on monitor  201 . 
       FIG. 16  illustrates a plurality of textures utilized to display wrinkles on monitor  201  ( FIG. 2 ). As illustrated in  FIG. 16 , RAM  206  ( FIG. 2 ) includes area  305 . Area  305  stores a plurality of textures which are pasted on polygons, i.e., textures Tx  510 , Tx  511 , Tx  512 , and Tx  513 . Tx  510  includes an image of wrinkle  410  illustrated in  FIG. 15   b ; Tx  511  includes an image of a larger wrinkle  410  illustrated in  FIG. 15   c ; Tx  512  includes an image of wrinkle  410  illustrated in  FIG. 15   d ; and Tx  513  includes an image of wrinkle  410  illustrated in  FIG. 15   e.    
       FIG. 17  illustrates the operation of wrinkle generating software stored in area  301  ( FIG. 3 ) of RAM  206  ( FIG. 2 ). First of all, CPU  211  ( FIG. 2 ) calculates the angle of joint JT produced by lower arm LA and upper arm UA. If the angle is 180 degrees (S 1   a ), CPU  211  does not access area  305  ( FIG. 16 ) of RAM  206  ( FIG. 2 ) (S 2   a ). If the angle is less than 180 degrees and 160 degrees or more (S 1   b ), CPU  211  retrieves Tx  510  from area  305  ( FIG. 16 ) of RAM  206  (S 2   b ). In the same manner, if the angle is less than 160 degrees and 135 degrees or more (S 1   c ), CPU  211  retrieves Tx  511  from area  305  of RAM  206  (S 2   c ); if the angle is less than 135 degrees and 110 degrees or more (S 1   d ), CPU  211  retrieves Tx  512  from area  305  of RAM  206  (S 2   d ); and if the angle is less than 110 degrees and 20 degrees or more (S 1   e ), CPU  211  retrieves Tx  513  from area  305  of RAM  206  (S 2   e ). 
     Instead of pasting textures to polygons in order to display wrinkles, a plurality of polygons may be used to produce wrinkles as described in  FIG. 18   a  through  FIG. 18   e . Assuming that arm AR is covered with fabric FB. When arm AR is stretched as described in  FIG. 18   a  and the angle of joint JT produced by lower arm LA and upper arm UA is 180 degrees, no wrinkles are shown on or near joint JT. As illustrated in  FIG. 18   b , a small wrinkle  410  can be produced by two small polygons, i.e., P 16  and P 17 . As illustrated in  FIG. 18   c , a larger wrinkle  410  than the one described in  FIG. 18   b  can be produced by the same set of polygons, i.e., P 16  and P 17  by stretching them vertically. As illustrated in  FIG. 18   d , a larger wrinkle  410  than the one described in  FIG. 18   c  can be produced by the same set of polygons, i.e., P 16  and P 17  by further stretching them vertically. As illustrated in  FIG. 18   e , a larger wrinkle  410  than the one described in  FIG. 18   d  can be produced by the same set of polygons, i.e., P 16  and P 17  by even more stretching them vertically. The operation of the wrinkle generating software in this embodiment is similar to the one described in  FIG. 11 . Such operation is not shown in the drawings. First of all, CPU  211  ( FIG. 2 ) calculates the angle of joint JT produced by lower arm LA and upper arm UA. If the angle is 180 degrees, CPU  211  does not produce any wrinkles with polygons. If the angle is less than 180 degrees and 160 degrees or more, CPU  211  produces a small set of polygons P 16  and P 17  to display one wrinkle, wrinkle  410 , as illustrated in  FIG. 18   b . In the same manner, if the angle is less than 160 degrees and 135 degrees or more, CPU  211  stretches polygons P 16  and P 17  vertically and makes wrinkle  410  as illustrated in  FIG. 18   c ; if the angle is less than 135 degrees and 110 degrees or more, CPU  211  further stretches polygons P 16  and P 17  vertically and make wrinkle  410  as illustrated in  FIG. 18   d ; and if the angle is less than 110 degrees and 20 degrees or more, CPU  211  even more stretches polygons P 16  and P 17  vertically and make wrinkle  410  as illustrated in  FIG. 18   e.    
       FIG. 19  through  FIG. 24   e  illustrate the method of determining the amount and the height of wrinkles that should be displayed on monitor  201  ( FIG. 2 ). 
     As illustrated in  FIG. 19 , RAM  206  ( FIG. 2 ) includes area  306 . Area  306  stores a plurality of data which are necessary to determine the amount and the height of the wrinkles. 
       FIG. 20  illustrates the content of area  306  ( FIG. 19 ) of RAM  206  ( FIG. 2 ). As illustrated in  FIG. 20 , area  306  includes three types of data, i.e., the data representing the angle of joint JT ( FIG. 4 ) produced by upper arm UA ( FIG. 4 ) and lower arm LA ( FIG. 4 ), the data representing the amount of wrinkles displayed, and the data representing the height of wrinkles displayed. For example, the amount and the height of wrinkle displayed is 0 when the angle of joint JT produced by upper arm UA and lower arm LA is 180 degrees. However, the amount of the wrinkle displayed is 1 and the height of the wrinkle displayed is 1 when the angle is less than 180 degrees and 160 degrees or more; the amount of the wrinkle displayed is 1 and the height of wrinkle displayed is 2 when the angle is less than 160 degrees and 135 degrees or more; the amount of the wrinkles displayed is 3 and the height of the wrinkles displayed is 1, 2, and 1 respectively when the angle is less than 135 degrees and 110 degrees or more; and the amount of the wrinkles displayed is 5 and the height of the wrinkles displayed is 1, 2, 3, 2, and 1 respectively when the angle is less than 110 degrees and 20 degrees or more. 
       FIG. 21   a  through  FIG. 21   e  illustrate how arm AR is displayed on monitor  201  ( FIG. 2 ) in accordance with the data stored in area  306  ( FIG. 19 ) of RAM  206  ( FIG. 2 ). Assuming that arm AR is covered with fabric FB. When arm AR is stretched as described in  FIG. 21   a  and the angle of joint JT produced by lower arm LA and upper arm UA is 180 degrees, no wrinkles are shown on or near joint JT. As illustrated in  FIG. 21   b , when arm AR is slightly bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 180 degrees and 160 degrees or more, a small wrinkle, i.e., wrinkle  411  is displayed on monitor  201 . As illustrated in  FIG. 21   c , when arm AR is further bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 160 degrees and 135 degrees or more, wrinkle  411  which is larger than the one described in  FIG. 21   b  is displayed on monitor  201 . As illustrated in  FIG. 21   d , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 135 degrees and 110 degrees or more, wrinkle  411  as large as the one described in  FIG. 21   c  is displayed on monitor  201  and two small wrinkles, i.e., wrinkles  412  and  413  appear on left and right sides of wrinkle  411  respectively. As illustrated in  FIG. 21   e , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 110 degrees and 20 degrees or more, wrinkle  411  larger than the one described in  FIG. 21   d  is displayed on monitor  201  and wrinkles  412  and  413  as large as the one described in  FIG. 21   c  appear on both sides of wrinkle  411  respectively, and in addition small wrinkles  414  and  420  appear adjacent to wrinkles  412  and  413  respectively. 
       FIG. 22  illustrates a plurality of textures utilized to display wrinkles on monitor  201  ( FIG. 2 ). As illustrated in  FIG. 22 , RAM  206  ( FIG. 2 ) includes area  307 . Area  307  stores a plurality of textures which are pasted on polygons, i.e., textures Tx  515 , Tx  516 , Tx  517 , and Tx  518 . Tx  515  includes the image of wrinkle  411  illustrated in  FIG. 21   b ; Tx  516  includes the image of wrinkle  411  illustrated in  FIG. 21   c ; Tx  517  includes the image of wrinkles  411 ,  412 , and  413  illustrated in  FIG. 21   d ; and Tx  518  includes the image of wrinkles  411 ,  412 ,  413 ,  414 , and  420  illustrated in  FIG. 21   e.    
       FIG. 23  illustrates the operation of wrinkle generating software stored in area  301  ( FIG. 3 ) of RAM  206  ( FIG. 2 ). First of all, CPU  211  ( FIG. 2 ) calculates the angle of joint JT produced by lower arm LA and upper arm UA. If the angle is 180 degrees (S 1   a ), CPU  211  does not access area  307  ( FIG. 22 ) of RAM  206  (S 2   a ). If the angle is less than 180 degrees and 160 degrees or more (S 1   b ), CPU  211  retrieves Tx  515  from area  307  of RAM  206  (S 2   b ). In the same manner, if the angle is less than 160 degrees and 135 degrees or more (S 1   c ), CPU  211  retrieves Tx  516  from area  307  of RAM  206  (S 2   c ); if the angle is less than 135 degrees and 110 degrees or more (S 1   d ), CPU  211  retrieves Tx  517  from area  307  of RAM  206  (S 2   d ); and if the angle is less than 110 degrees and 20 degrees or more (S 1   e ), CPU  211  retrieves Tx  518  from area  307  of RAM  206  (S 2   e ). 
     Instead of pasting textures to polygons in order to display wrinkles, a plurality of polygons may be used to produce wrinkles as described in  FIG. 24   a  through  FIG. 24   e . Assuming that arm AR is covered with fabric FB. When arm AR is stretched as described in  FIG. 24   a  and the angle of joint JT produced by lower arm LA and upper arm UA is 180 degrees, no wrinkles are shown on or near joint JT. As illustrated in  FIG. 24   b , when arm AR is slightly bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 180 degrees and 160 degrees or more, a small wrinkle, i.e., wrinkle  411  is displayed on monitor  201  by a set of two polygons P 16  and P 17 . As illustrated in  FIG. 24   c , when arm AR is further bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 160 degrees and 135 degrees or more, wrinkle  411  which is larger than the one described in  FIG. 24   b  is displayed on monitor  201  by stretching the set of two polygons P 16  and P 17  vertically. As illustrated in  FIG. 24   d , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 135 degrees and 110 degrees or more, wrinkle  411  as large as the one described in  FIG. 24   c  is displayed on monitor  201  by the set of polygons P 16  and P 17  and two small wrinkles, i.e., wrinkles  412  and  413  appear on left and right sides of wrinkle  411  respectively. Wrinkle  412  is produced by the set of polygons P 18  and P 19 , and wrinkle  413  is produced by the set of polygons P 20  and P 21 . As illustrated in  FIG. 21   e , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 110 degrees and 20 degrees or more, wrinkle  411  larger than the one described in  FIG. 21   d  is displayed on monitor  201  by further stretching the set of polygons P 16  and P 17  vertically and wrinkles  412  and  413  as large as wrinkle  411  in  FIG. 21   d  appear on both sides of wrinkle  411  respectively. Here, wrinkles  412  and  413  are produced by the sets of P 18  and P 19 , and P 20  and P 21  respectively, and they are stretched to increase the height. Additional wrinkles  414  and  420  appear adjacent to wrinkles  412  and  413  respectively where wrinkle  414  and  420  are produced by the sets of P 22  and P 23 , and P 24  and P 25  respectively. The operation of the wrinkle generating software in this embodiment is similar to the one described in  FIG. 11 . Such operation is not shown in the drawings. First of all, CPU  211  ( FIG. 2 ) calculates the angle of joint JT produced by lower arm LA and upper arm UA. If the angle is 180 degrees, CPU  211  does not produce any wrinkles with polygons. If the angle is less than 180 degrees and 160 degrees or more, CPU  211  produces a small set of polygons P 16  and P 17  to display wrinkle  411  as illustrated in  FIG. 24   b . In the same manner, if the angle is less than 160 degrees and 135 degrees or more, CPU  211  stretches the polygons P 16  and P 17  vertically and make wrinkle  411  as illustrated in  FIG. 24   c ; if the angle is less than 135 degrees and 110 degrees or more, CPU  211  stretches the polygons P 16  and P 17  vertically and make wrinkle  411  as illustrated in  FIG. 24   d  and add two small wrinkles, i.e., wrinkle  412  and  413  by producing P 18  and P 19 , and P 20  and P 21  respectively; and if the angle is less than 110 degrees and 20 degrees or more, CPU  211  further stretches the polygons P 16  and P 17  vertically and make wrinkle  411  as illustrated in  FIG. 24   e . CPU  211  increases the height of wrinkles  412  and  413  by stretching the two sets of polygons P 18  and P 19 , and P 20  and P 21  respectively. In addition, CPU  211  adds two small wrinkles  414  and  420  adjacent to wrinkles  412  and  413  respectively by producing two sets of polygons P 22  and P 23 , and P 24  and P 25  respectively. 
       FIG. 25  through  FIG. 32   e  illustrate the method of determining the muscle movement of upper arm UA. 
       FIG. 25  illustrates the content of area  308  of RAM  206  ( FIG. 2 ). Area  308  stores the muscle movement generating software which administers the muscle movement of upper arm UA as described in details hereinafter. 
       FIG. 26  illustrates the concept of the present invention. As described in  FIG. 26 , arm AR of an object (human being) is composed of hand HD, lower arm LA, joint JT, and upper arm UA. When arm AR is bent, muscle M bulges and thereby increases the thickness of upper arm UA. 
       FIG. 27  illustrates the method of generating the muscle movement. The most convenient way to generate the muscle movement is to have the muscle M composed with a plurality of polygons. In the example described in  FIG. 27 , muscle M is composed of polygons P 42 , P 43 , P 44 , and P 45 . Polygons P 46  and P 47  are part of upper arm UA, but not part of muscle M. 
     As illustrated in  FIG. 28 , RAM  206  ( FIG. 2 ) includes area  309 . Area  309  stores a plurality of data which are necessary to produce the muscle movement of upper arm UA. 
       FIG. 29  illustrates the content of area  309  ( FIG. 28 ) of RAM  206 . Area  309  includes two types of data, i.e., the data representing the angle of joint JT ( FIG. 26 ) produced by upper arm UA ( FIG. 26 ) and lower arm LA ( FIG. 26 ), and the data representing the property of the muscle movement. The more the value of the muscle property increases the more the thickness of upper arm UA increases. For example, the value of the muscle property is 0 when the angle of joint JT produced by upper arm UA and lower arm LA is 180 degrees. The value of the muscle property increases as the angle of joint JT produced by upper arm UA and lower arm LA decreases. In the present example described in  FIG. 29 , the value of the muscle property is 1 when the angle is less than 180 degrees and 160 degrees or more; the value of the muscle property is 2 when the angle is less than 160 degrees and 135 degrees or more; the value of the muscle property is 3 when the angle is less than 135 degrees and 110 degrees or more; and the value of the muscle property is 4 when the angle is less than 110 degrees and 20 degrees or more. 
       FIG. 30   a  through  FIG. 30   e  illustrate how arm AR is displayed on monitor  201  ( FIG. 2 ) in accordance with the data stored in area  309  ( FIG. 28 ) of RAM  206  ( FIG. 2 ). When arm AR is stretched as described in  FIG. 30   a  and the angle of joint JT produced by lower arm LA and upper arm UA is 180 degrees, no muscle movement appears on upper arm UA. As described in  FIG. 30   b , when arm AR is slightly bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 180 degrees and 160 degrees or more, the muscle movement occurs and muscle M bulges. As described in  FIG. 30   c , when arm AR is further bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 160 degrees and 135 degrees or more, muscle M bulges more compared to the one shown in  FIG. 30   b . As described in  FIG. 30   d , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 135 degrees and 110 degrees or more, muscle M bulges more compared to the one shown in  FIG. 30   c . As described in  FIG. 30   e , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 110 degrees and 20 degrees or more, muscle M bulges more compared to the one shown in  FIG. 30   d.    
       FIG. 31  illustrates the operation of the muscle movement generating software stored in area  308  ( FIG. 25 ) of RAM  206  ( FIG. 2 ). First of all, CPU  211  ( FIG. 2 ) calculates the angle of joint JT produced by lower arm LA and upper arm UA. If the angle is 180 degrees (S 1   a ), CPU  211  retrieves the muscle property data from area  309  ( FIG. 29 ) of RAM  206  ( FIG. 2 ). Since the muscle property is 0, no muscle movement occurs and upper arm UA described in  FIG. 30   a  is shown (S 2   a ). If the angle is less than 180 degrees and 160 degrees or more (S 1   b ), CPU  211  retrieves the muscle property which is 1 and upper arm UA described in  FIG. 30   b  is shown (S 2   b ). In the same manner, if the angle is less than 160 degrees and 135 degrees or more (S 1   c ), CPU  211  retrieves the muscle property which is 2 and upper arm UA described in  FIG. 30   c  is shown (S 2   c ); if the angle is less than 135 degrees and 110 degrees or more (S 1   d ), CPU  211  retrieves the muscle property which is 3 and upper arm UA described in  FIG. 30   d  is shown (S 2   d ); and if the angle is less than 110 degrees and 20 degrees or more (S 1   e ), CPU  211  retrieves the muscle property which is 4 and upper arm UA described in  FIG. 30   e  is shown (S 2   e ). 
       FIG. 32   a  through  FIG. 32   e  illustrate how the polygons are utilized in displaying the muscle movement. 
     As illustrated in  FIG. 32   a , when arm AR is stretched and the angle of joint JT produced by lower arm LA and upper arm UA is 180 degrees, no muscle movement appears on upper arm UA and the polygons consisting of muscle M, i.e., P 27 , P 28 , and P 29  remains in a straight line or almost in a straight line. Polygons P 26  and P 30  are part of upper arm UA, however, does not compose muscle M. As described in  FIG. 32   b , when arm AR is slightly bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 180 degrees and 160 degrees or more, the muscle movement occurs and muscle M composed of polygons P 27 , P 28  and P 29  bulges. As described in  FIG. 32   c , when arm AR is further bent and the angle of joint JT produced by lower arm LA and upper arm UA is less than 160 degrees and 135 degrees or more, muscle M composed of polygons P 27 , P 28  and P 29  bulges more compared to the one shown in  FIG. 32   b . As described in  FIG. 32   d , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 135 degrees and 110 degrees or more, muscle M composed of polygons P 27 , P 28  and P 29  bulges more compared to the one shown in  FIG. 32   c . As described in  FIG. 32   e , when the angle of joint JT produced by lower arm LA and upper arm UA is less than 110 degrees and 20 degrees or more, muscle M bulges more compared to the one shown in  FIG. 32   d . Here, muscle M is composed of polygons P 27 , P 28  and P 29 , and new polygons P 31  and P 32  are inserted between P 27  and P 28 , and P 28  and P 29 , respectively. 
     Having thus described a presently preferred embodiment of the present invention, it will be understood by those skilled in the art that many changes in construction and circuitry and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the present invention. The disclosures and the description herein are intended to be illustrative and are not in any sense limiting of the invention, more preferably defined in scope by the following claims.