1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/******************************************************************************
* SOFA, Simulation Open-Framework Architecture, version 1.0 beta 4 *
* (c) 2006-2009 MGH, INRIA, USTL, UJF, CNRS *
* *
* This library is free software; you can redistribute it and/or modify it *
* under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation; either version 2.1 of the License, or (at *
* your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, but WITHOUT *
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or *
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License *
* for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this library; if not, write to the Free Software Foundation, *
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
*******************************************************************************
* SOFA :: Modules *
* *
* Authors: The SOFA Team and external contributors (see Authors.txt) *
* *
* Contact information: contact@sofa-framework.org *
******************************************************************************/
#ifndef SOFA_COMPONENT_FORCEFIELD_TRIANGLEFEMFORCEFIELD_H
#define SOFA_COMPONENT_FORCEFIELD_TRIANGLEFEMFORCEFIELD_H
#if !defined(__GNUC__) || (__GNUC__ > 3 || (_GNUC__ == 3 && __GNUC_MINOR__ > 3))
#pragma once
#endif
#include <sofa/core/componentmodel/behavior/ForceField.h>
#include <sofa/core/componentmodel/topology/BaseMeshTopology.h>
#include <sofa/defaulttype/Vec.h>
#include <sofa/defaulttype/Mat.h>
// corotational triangle from
// @InProceedings{NPF05,
// author = "Nesme, Matthieu and Payan, Yohan and Faure, Fran\c{c}ois",
// title = "Efficient, Physically Plausible Finite Elements",
// booktitle = "Eurographics (short papers)",
// month = "august",
// year = "2005",
// editor = "J. Dingliana and F. Ganovelli",
// keywords = "animation, physical model, elasticity, finite elements",
// url = "http://www-evasion.imag.fr/Publications/2005/NPF05"
// }
namespace sofa
{
namespace component
{
namespace forcefield
{
using namespace sofa::defaulttype;
template<class DataTypes>
class TriangleFEMForceField : public core::componentmodel::behavior::ForceField<DataTypes>, public virtual core::objectmodel::BaseObject
{
public:
typedef core::componentmodel::behavior::ForceField<DataTypes> Inherited;
typedef typename DataTypes::VecCoord VecCoord;
typedef typename DataTypes::VecDeriv VecDeriv;
typedef typename DataTypes::Coord Coord ;
typedef typename DataTypes::Deriv Deriv ;
typedef typename Coord::value_type Real ;
typedef sofa::core::componentmodel::topology::BaseMeshTopology::index_type Index;
typedef sofa::core::componentmodel::topology::BaseMeshTopology::Triangle Element;
typedef sofa::core::componentmodel::topology::BaseMeshTopology::SeqTriangles VecElement;
static const int SMALL = 1; ///< Symbol of small displacements triangle solver
static const int LARGE = 0; ///< Symbol of large displacements triangle solver
protected:
// component::MechanicalObject<DataTypes>* _object;
typedef Vec<6, Real> Displacement; ///< the displacement vector
typedef Mat<3, 3, Real> MaterialStiffness; ///< the matrix of material stiffness
typedef sofa::helper::vector<MaterialStiffness> VecMaterialStiffness; ///< a vector of material stiffness matrices
VecMaterialStiffness _materialsStiffnesses; ///< the material stiffness matrices vector
typedef Mat<6, 3, Real> StrainDisplacement; ///< the strain-displacement matrix
typedef sofa::helper::vector<StrainDisplacement> VecStrainDisplacement; ///< a vector of strain-displacement matrices
VecStrainDisplacement _strainDisplacements; ///< the strain-displacement matrices vector
typedef Mat<3, 3, Real > Transformation; ///< matrix for rigid transformations like rotations
sofa::core::componentmodel::topology::BaseMeshTopology* _mesh;
const VecElement *_indexedElements;
Data< VecCoord > _initialPoints; ///< the intial positions of the points
// int _method; ///< the computation method of the displacements
// Real _poissonRatio;
// Real _youngModulus;
// Real _dampingRatio;
public:
TriangleFEMForceField();
//virtual const char* getTypeName() const { return "TriangleFEMForceField"; }
virtual ~TriangleFEMForceField();
virtual void init();
virtual void reinit();
virtual void addForce (VecDeriv& f, const VecCoord& x, const VecDeriv& v);
virtual void addDForce (VecDeriv& df, const VecDeriv& dx);
virtual double getPotentialEnergy(const VecCoord& x);
void draw();
int method;
Data<std::string> f_method;
Data<Real> f_poisson;
Data<Real> f_young;
Data<Real> f_damping;
Real getPoisson() { return f_poisson.getValue(); }
void setPoisson(Real val) { f_poisson.setValue(val); }
Real getYoung() { return f_young.getValue(); }
void setYoung(Real val) { f_young.setValue(val); }
Real getDamping() { return f_damping.getValue(); }
void setDamping(Real val) { f_damping.setValue(val); }
int getMethod() { return method; }
void setMethod(int val) { method = val; }
// component::MechanicalObject<DataTypes>* getObject()
// {
// return _object;
// }
protected :
/// f += Kx where K is the stiffness matrix and x a displacement
virtual void applyStiffness( VecCoord& f, Real h, const VecCoord& x );
void computeStrainDisplacement( StrainDisplacement &J, Coord a, Coord b, Coord c);
void computeMaterialStiffnesses();
void computeForce( Displacement &F, const Displacement &Depl, const MaterialStiffness &K, const StrainDisplacement &J );
////////////// small displacements method
void initSmall();
void accumulateForceSmall( VecCoord& f, const VecCoord & p, Index elementIndex, bool implicit = false );
void accumulateDampingSmall( VecCoord& f, Index elementIndex );
void applyStiffnessSmall( VecCoord& f, Real h, const VecCoord& x );
////////////// large displacements method
sofa::helper::vector< helper::fixed_array <Coord, 3> > _rotatedInitialElements; ///< The initials positions in its frame
sofa::helper::vector< Transformation > _rotations;
void initLarge();
void computeRotationLarge( Transformation &r, const VecCoord &p, const Index &a, const Index &b, const Index &c);
void accumulateForceLarge( VecCoord& f, const VecCoord & p, Index elementIndex, bool implicit=false );
void accumulateDampingLarge( VecCoord& f, Index elementIndex );
void applyStiffnessLarge( VecCoord& f, Real h, const VecCoord& x );
};
} // namespace forcefield
} // namespace component
} // namespace sofa
#endif
|
