FEMMass

Finite-element mass (inertia and body force)

Templates:

Vec1d,Edge
Vec1d,QuadraticEdge

Target: Sofa.Component.Mass

namespace: sofa::component::mass

parents:

Mass
TopologyAccessor

Data

Name	Description	Default value
name	object name	unnamed
printLog	if true, emits extra messages at runtime.	0
tags	list of the subsets the object belongs to
bbox	this object bounding box
componentState	The state of the component among (Dirty, Valid, Undefined, Loading, Invalid).	Undefined
listening	if true, handle the events, otherwise ignore the events	0
rayleighStiffness	Rayleigh damping - stiffness matrix coefficient	0
separateGravity	add separately gravity to velocity computation	0
rayleighMass	Rayleigh damping - mass matrix coefficient	0
lumping	If true, the mass matrix is lumped, meaning the mass matrix is approximated to a diagonal matrix (summing all mass values of a line on the diagonal)

Links

Name	Description	Destination type name
context	Graph Node containing this object (or BaseContext::getDefault() if no graph is used)	BaseContext
slaves	Sub-objects used internally by this object	BaseComponent
master	nullptr for regular objects, or master object for which this object is one sub-objects	BaseComponent
mechanicalStates	List of mechanical states to which this component is associated	BaseMechanicalState
mstate	MechanicalState used by this component	MechanicalState<Vec1d>
topology	Link to a topology	BaseMeshTopology
nodalMassDensity	Link to nodal mass density	NodalMassDensity<d>

Vec2d,Edge...

Templates:

Vec2d,Edge
Vec2d,Quad
Vec2d,QuadraticEdge
Vec2d,QuadraticQuad
Vec2d,QuadraticTriangle
Vec2d,Triangle

Target: Sofa.Component.Mass

namespace: sofa::component::mass

parents:

Mass
TopologyAccessor

Data

Name	Description	Default value
name	object name	unnamed
printLog	if true, emits extra messages at runtime.	0
tags	list of the subsets the object belongs to
bbox	this object bounding box
componentState	The state of the component among (Dirty, Valid, Undefined, Loading, Invalid).	Undefined
listening	if true, handle the events, otherwise ignore the events	0
rayleighStiffness	Rayleigh damping - stiffness matrix coefficient	0
separateGravity	add separately gravity to velocity computation	0
rayleighMass	Rayleigh damping - mass matrix coefficient	0
lumping	If true, the mass matrix is lumped, meaning the mass matrix is approximated to a diagonal matrix (summing all mass values of a line on the diagonal)

Links

Name	Description	Destination type name
context	Graph Node containing this object (or BaseContext::getDefault() if no graph is used)	BaseContext
slaves	Sub-objects used internally by this object	BaseComponent
master	nullptr for regular objects, or master object for which this object is one sub-objects	BaseComponent
mechanicalStates	List of mechanical states to which this component is associated	BaseMechanicalState
mstate	MechanicalState used by this component	MechanicalState<Vec2d>
topology	Link to a topology	BaseMeshTopology
nodalMassDensity	Link to nodal mass density	NodalMassDensity<d>

Vec3d,Edge...

Templates:

Vec3d,Edge
Vec3d,Hexahedron
Vec3d,Prism
Vec3d,Pyramid
Vec3d,Quad
Vec3d,QuadraticEdge
Vec3d,QuadraticHexahedron
Vec3d,QuadraticQuad
Vec3d,QuadraticTetrahedron
Vec3d,QuadraticTriangle
Vec3d,Tetrahedron
Vec3d,Triangle

Target: Sofa.Component.Mass

namespace: sofa::component::mass

parents:

Mass
TopologyAccessor

Data

Name	Description	Default value
name	object name	unnamed
printLog	if true, emits extra messages at runtime.	0
tags	list of the subsets the object belongs to
bbox	this object bounding box
componentState	The state of the component among (Dirty, Valid, Undefined, Loading, Invalid).	Undefined
listening	if true, handle the events, otherwise ignore the events	0
rayleighStiffness	Rayleigh damping - stiffness matrix coefficient	0
separateGravity	add separately gravity to velocity computation	0
rayleighMass	Rayleigh damping - mass matrix coefficient	0
lumping	If true, the mass matrix is lumped, meaning the mass matrix is approximated to a diagonal matrix (summing all mass values of a line on the diagonal)

Links

Name	Description	Destination type name
context	Graph Node containing this object (or BaseContext::getDefault() if no graph is used)	BaseContext
slaves	Sub-objects used internally by this object	BaseComponent
master	nullptr for regular objects, or master object for which this object is one sub-objects	BaseComponent
mechanicalStates	List of mechanical states to which this component is associated	BaseMechanicalState
mstate	MechanicalState used by this component	MechanicalState<Vec3d>
topology	Link to a topology	BaseMeshTopology
nodalMassDensity	Link to nodal mass density	NodalMassDensity<d>

Examples

FEMMass_lumping.scn

XMLPython

<?xml version="1.0"?>
<Node name="root" dt="0.01" gravity="0 -9.81 0">

    <Node name="plugins">
        <RequiredPlugin pluginName="Sofa.Component.Constraint.Projective"/> <!-- Needed to use components [FixedProjectiveConstraint] -->
        <RequiredPlugin pluginName="Sofa.Component.Engine.Select"/> <!-- Needed to use components [BoxROI] -->
        <RequiredPlugin pluginName="Sofa.Component.LinearSolver.Direct"/> <!-- Needed to use components [SparseLDLSolver] -->
        <RequiredPlugin pluginName="Sofa.Component.LinearSolver.Iterative"/> <!-- Needed to use components [CGLinearSolver] -->
        <RequiredPlugin pluginName="Sofa.Component.LinearSolver.Ordering"/> <!-- Needed to use components [NaturalOrderingMethod] -->
        <RequiredPlugin pluginName="Sofa.Component.LinearSystem"/> <!-- Needed to use components [ConstantSparsityPatternSystem] -->
        <RequiredPlugin pluginName="Sofa.Component.Mass"/> <!-- Needed to use components [MeshMatrixMass] -->
        <RequiredPlugin pluginName="Sofa.Component.ODESolver.Backward"/> <!-- Needed to use components [EulerImplicitSolver] -->
        <RequiredPlugin pluginName="Sofa.Component.SolidMechanics.FEM.Elastic"/>
        <RequiredPlugin pluginName="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
        <RequiredPlugin pluginName="Sofa.Component.Topology.Container.Dynamic"/> <!-- Needed to use components [TetrahedronSetGeometryAlgorithms,TetrahedronSetTopologyContainer,TetrahedronSetTopologyModifier] -->
        <RequiredPlugin pluginName="Sofa.Component.Topology.Container.Grid"/> <!-- Needed to use components [RegularGridTopology] -->
        <RequiredPlugin pluginName="Sofa.Component.Topology.Mapping"/> <!-- Needed to use components [Hexa2TetraTopologicalMapping] -->
        <RequiredPlugin pluginName="Sofa.Component.Visual"/> <!-- Needed to use components [LineAxis,VisualGrid,VisualStyle] -->
        <RequiredPlugin pluginName="Sofa.GL.Component.Rendering3D"/> <!-- Needed to use components [OglSceneFrame] -->
    </Node>

    <DefaultAnimationLoop parallelODESolving="true"/>
    <VisualStyle displayFlags="showBehaviorModels showForceFields" />

    <VisualGrid size="0.1"/>
    <LineAxis size="0.1"/>
    <OglSceneFrame/>

    <Node name="consistent">
        <Visual3DText text="consistent mass" position="-0.09 0.03 0" scale="0.01" color="teal"/>
        <EulerImplicitSolver name="backward_Euler" rayleighStiffness="0.1" rayleighMass="0.1" />

        <ConstantSparsityPatternSystem template="CompressedRowSparseMatrix" name="A" checkIndices="false"/>
        <NaturalOrderingMethod/>
        <SparseLDLSolver name="linear_solver" template="CompressedRowSparseMatrix"/>

        <RegularGridTopology name="grid" min="-0.03 -0.01 0" max="-0.01 0.01 0.2" n="5 5 30"/>
        <MechanicalObject template="Vec3" name="state" showObject="true"/>

        <NodalMassDensity property="1100"/>
        <FEMMass template="Vec3,Hexahedron" lumping="false"/>

        <CorotationalFEMForceField name="FEM" template="Vec3,Hexahedron"
                                   youngModulus="1e5" poissonRatio="0.45" topology="@grid"
                                   computeForceStrategy="sequenced" computeForceDerivStrategy="sequenced"/>

        <BoxROI template="Vec3" name="box_roi" box="-0.031 -0.011 -0.0001   -0.009 0.011 0.0001" drawBoxes="1" />
        <FixedProjectiveConstraint template="Vec3" indices="@box_roi.indices" />
    </Node>

    <Node name="lumped">
        <Visual3DText text="lumped mass" position="0.01 0.03 0" scale="0.01" color="orange"/>
        <EulerImplicitSolver name="backward_Euler" rayleighStiffness="0.1" rayleighMass="0.1" />

        <ConstantSparsityPatternSystem template="CompressedRowSparseMatrix" name="A" checkIndices="false"/>
        <NaturalOrderingMethod/>
        <SparseLDLSolver name="linear_solver" template="CompressedRowSparseMatrix"/>

        <RegularGridTopology name="grid" min="0.01 -0.01 0" max="0.03 0.01 0.2" n="5 5 30"/>
        <MechanicalObject template="Vec3" name="state" showObject="true"/>

        <NodalMassDensity property="1100"/>
        <FEMMass template="Vec3,Hexahedron" lumping="true"/>

        <CorotationalFEMForceField name="FEM" template="Vec3,Hexahedron"
                                   youngModulus="1e5" poissonRatio="0.45" topology="@grid"
                                   computeForceStrategy="sequenced" computeForceDerivStrategy="sequenced"/>

        <BoxROI template="Vec3" name="box_roi" box="0.009 -0.011 -0.0001   0.031 0.011 0.0001" drawBoxes="1" />
        <FixedProjectiveConstraint template="Vec3" indices="@box_roi.indices" />
    </Node>
</Node>

def createScene(root_node):

   root = root_node.addChild('root', dt="0.01", gravity="0 -9.81 0")

   plugins = root.addChild('plugins')

   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.Constraint.Projective")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.Engine.Select")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.LinearSolver.Direct")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.LinearSolver.Iterative")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.LinearSolver.Ordering")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.LinearSystem")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.Mass")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.ODESolver.Backward")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.SolidMechanics.FEM.Elastic")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.StateContainer")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.Topology.Container.Dynamic")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.Topology.Container.Grid")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.Topology.Mapping")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.Component.Visual")
   plugins.addObject('RequiredPlugin', pluginName="Sofa.GL.Component.Rendering3D")

   root.addObject('DefaultAnimationLoop', parallelODESolving="true")
   root.addObject('VisualStyle', displayFlags="showBehaviorModels showForceFields")
   root.addObject('VisualGrid', size="0.1")
   root.addObject('LineAxis', size="0.1")
   root.addObject('OglSceneFrame', )

   consistent = root.addChild('consistent')

   consistent.addObject('Visual3DText', text="consistent mass", position="-0.09 0.03 0", scale="0.01", color="teal")
   consistent.addObject('EulerImplicitSolver', name="backward_Euler", rayleighStiffness="0.1", rayleighMass="0.1")
   consistent.addObject('ConstantSparsityPatternSystem', template="CompressedRowSparseMatrix", name="A", checkIndices="false")
   consistent.addObject('NaturalOrderingMethod', )
   consistent.addObject('SparseLDLSolver', name="linear_solver", template="CompressedRowSparseMatrix")
   consistent.addObject('RegularGridTopology', name="grid", min="-0.03 -0.01 0", max="-0.01 0.01 0.2", n="5 5 30")
   consistent.addObject('MechanicalObject', template="Vec3", name="state", showObject="true")
   consistent.addObject('NodalMassDensity', property="1100")
   consistent.addObject('FEMMass', template="Vec3,Hexahedron", lumping="false")
   consistent.addObject('CorotationalFEMForceField', name="FEM", template="Vec3,Hexahedron", youngModulus="1e5", poissonRatio="0.45", topology="@grid", computeForceStrategy="sequenced", computeForceDerivStrategy="sequenced")
   consistent.addObject('BoxROI', template="Vec3", name="box_roi", box="-0.031 -0.011 -0.0001   -0.009 0.011 0.0001", drawBoxes="1")
   consistent.addObject('FixedProjectiveConstraint', template="Vec3", indices="@box_roi.indices")

   lumped = root.addChild('lumped')

   lumped.addObject('Visual3DText', text="lumped mass", position="0.01 0.03 0", scale="0.01", color="orange")
   lumped.addObject('EulerImplicitSolver', name="backward_Euler", rayleighStiffness="0.1", rayleighMass="0.1")
   lumped.addObject('ConstantSparsityPatternSystem', template="CompressedRowSparseMatrix", name="A", checkIndices="false")
   lumped.addObject('NaturalOrderingMethod', )
   lumped.addObject('SparseLDLSolver', name="linear_solver", template="CompressedRowSparseMatrix")
   lumped.addObject('RegularGridTopology', name="grid", min="0.01 -0.01 0", max="0.03 0.01 0.2", n="5 5 30")
   lumped.addObject('MechanicalObject', template="Vec3", name="state", showObject="true")
   lumped.addObject('NodalMassDensity', property="1100")
   lumped.addObject('FEMMass', template="Vec3,Hexahedron", lumping="true")
   lumped.addObject('CorotationalFEMForceField', name="FEM", template="Vec3,Hexahedron", youngModulus="1e5", poissonRatio="0.45", topology="@grid", computeForceStrategy="sequenced", computeForceDerivStrategy="sequenced")
   lumped.addObject('BoxROI', template="Vec3", name="box_roi", box="0.009 -0.011 -0.0001   0.031 0.011 0.0001", drawBoxes="1")
   lumped.addObject('FixedProjectiveConstraint', template="Vec3", indices="@box_roi.indices")