Immediate buckling model, hysteresis model, and cloth simulation method based on the invented models, and computer-readable media storing a program which executes the invented simulation method

Abstract

A method of simulating the movement of cloth and a computer-readable medium storing a program which executes the method of simulating the movement of cloth, wherein cloth deformation by compressive force is simulated by an immediate buckling model when the compressive force is applied to two extremities of a deformation unit which models the cloth, cloth deformation by stretching is simulated by a spring model, and hysteresis phenomenon of cloth is simulated by using spring-slips for modeling. The immediate buckling model is based on a model of the present invention in which a deformation unit is not contracted by compressive force and generates an immediate bending deformation. As for the compressive force and stretching, simulation is implemented by separate models, hysteresis phenomenon of cloth is simulated by use of spring-clips for modeling, whereby cloth characteristics can be well reflected and the buckling instability of cloth caused by compressive force can be solved, thereby increasing the simulation speed.

1 . A method of simulating the movement of cloth, the method comprising a step of using an immediate buckling model, wherein the deformation unit which represents the part of the cloth of interest is bent immediately without contraction when compressive force is applied to two extremities of said deformation unit.  
     
     
         2 . A method of simulating the movement of cloth, the method comprising a step of estimating the shape of said deformation unit upon application of compressive force as a function of the distance between two extremities of said deformation unit.  
     
     
         3 . A method of simulating the movement of cloth, the method comprising a step of calculating the bending deformation energy stored in said deformation unit by estimating the shape of the deformation unit according to the method defined in  claim 2 .  
     
     
         4 . Means for modeling hysteresis characteristics between bending moment and curvature of cloth, wherein the means uses n slip units and n+1 springs, wherein each slip unit makes a serial connection with a spring unit resulting in n pairs of spring-slip units, and said n pairs of spring-slip units and the remaining spring are connected in parallel.  
     
     
         5 . The means as defined in  claim 4 , wherein, by taking said number n to infinity, the means approximates the moment-curvature relationship with piece-wise second degree polynomial functions.  
     
     
         6 . The method as defined in  claim 2 , wherein the estimating step further comprises the steps of: estimating the curvature of said deformation unit as a function of distance between two extremities of said deformation unit; and estimating the shape of the bending deformation from the estimated curvature.  
     
     
         7 . The method as defined in  claim 3 , the method further comprising the steps of: differentiating the bending deformation energy to obtain the force vector at the two extremities of the deformation unit; and obtaining the Jacobian matrix of the force vector, wherein the Jacobian matrix is an element for simulating the bending deformation of cloth.  
     
     
         8 . The method as defined in  claim 7 , wherein terms having negative eigenvalues are dropped from the Jacobian matrix.  
     
     
         9 . The method of simulating the movement of cloth, wherein a hysteresis characteristic between the curvature and bending moment is obtained by the means defined in  claim 4  or  claim 5 .  
     
     
         10 . The method as defined in any one of claims  1 ,  2 ,  3 ,  6 ,  7  and  8 , wherein the deformation unit comprises a plurality of adjacent particles when cloth is modeled as a particle model.  
     
     
         11 . A computer-readable medium storing a program which executes a method of simulating the movement of cloth, wherein the method comprising a step of using an immediate buckling model, wherein the deformation unit which represents the part of the cloth of interest is bent immediately without contraction when compressive force is applied to two extremities of said deformation unit.  
     
     
         12 . A computer-readable medium storing a program which executes a method of simulating the movement of cloth, the method comprising a step of estimating the shape of said deformation unit upon application of compressive force as a function of the distance between two extremities of said deformation unit.  
     
     
         13 . A computer-readable medium storing a program which executes a method of simulating the movement of cloth, the method comprising a step of calculating the bending deformation energy stored in said deformation unit by estimating the shape of the deformation unit according to the method defined in  claim 12 .  
     
     
         14 . The medium as defined in  claim 12 , wherein the estimating step further comprises the steps of: estimating the curvature of said deformation unit as a function of distance between two extremities of said deformation unit; and estimating the shape of the bending deformation from the estimated curvature.  
     
     
         15 . The medium as defined in  claim 13 , wherein the method further comprising the steps of: differentiating the bending deformation energy to obtain the force vector at the two extremities of the deformation unit; and obtaining the Jacobian matrix of the force vector, wherein the Jacobian matrix is an element for simulating the bending deformation of cloth.  
     
     
         16 . The medium as defined in  claim 15 , wherein terms having negative eigenvalues are dropped from the Jacobian matrix.  
     
     
         17 . The computer-readable medium storing a program which executes a method of simulating the movement of cloth, wherein a hysteresis characteristic between the curvature and bending moment is obtained by the means defined in  claim 4  or  claim 5 .  
     
     
         18 . The medium as defined in any one of claims  11 ,  12 ,  13 ,  14 ,  15  and  16 , wherein said deformation unit comprises a plurality of adjacent particles when the cloth is modeled as a particle model.  
     
     
         19 . A method of simulating the movement of cloth, the method comprising the steps of: 
 estimating the shape of bending deformation occurring on deformation  2 , unit which represents the part of the cloth of interest by using an immediate buckling model wherein the deformation unit is bent immediately without contraction when compressive force is applied to two extremities of said deformation unit;    obtaining bending deformation energy accumulated on said deformation unit by estimating the shape of said deformation unit; and    simulating the bending deformation of cloth by using the bending deformation energy.    
     
     
         20 . A computer-readable medium storing a program which executes a method of simulating movement of cloth, wherein the method comprises the steps of: 
 estimating the shape of bending deformation occurring on deformation unit which represents the part of the cloth of interest by using an immediate buckling model wherein the deformation unit is bent immediately without contraction when compressive force is applied to two extremities of said deformation unit;    obtaining bending deformation energy accumulated on said deformation unit by estimating the shape of said deformation unit; and    simulating the bending deformation of cloth by using the bending deformation energy.