CorotationalFEMForceField

Hooke's law using the corotational approach

Templates:

• Vec2d,Edge
• Vec2d,Quad
• Vec2d,Triangle

Target: Sofa.Component.SolidMechanics.FEM.Elastic

namespace: sofa::component::solidmechanics::fem::elastic

parents:

• BaseElementLinearFEMForceField
• FEMForceField

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
nbThreads	If not yet initialized, the main task scheduler is initialized with this number of threads. 0 corresponds to the number of available cores on the CPU. -n (minus) corresponds to the number of available cores on the CPU minus the provided number.	0
taskSchedulerType	Type of task scheduler to use.	_default
poissonRatio	FEM Poisson Ratio in Hooke's law [0,0.5[	0.45
youngModulus	FEM Young's Modulus in Hooke's law	5000
elementStiffness	List of stiffness matrices per element
rotationMethod	The method used to compute the element rotations. - stable_polar: Stable polar decomposition - polar: Polar decomposition - identity: Identity rotation. Equivalent to the linear small strain FEM.
Multithreading
computeForceStrategy	The compute strategy used to compute the forces. - parallel: The algorithm is executed in parallel - sequenced: The algorithm is executed sequentially
computeForceDerivStrategy	The compute strategy used to compute the forces derivatives. - parallel: The algorithm is executed in parallel - sequenced: The algorithm is executed sequentially
Visualization
elementSpace	When rendering, the space between elements	0.125

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

Vec3d,Edge...

Templates:

• Vec3d,Edge
• Vec3d,Prism
• Vec3d,Quad

Target: Sofa.Component.SolidMechanics.FEM.Elastic

namespace: sofa::component::solidmechanics::fem::elastic

parents:

• BaseElementLinearFEMForceField
• FEMForceField

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
nbThreads	If not yet initialized, the main task scheduler is initialized with this number of threads. 0 corresponds to the number of available cores on the CPU. -n (minus) corresponds to the number of available cores on the CPU minus the provided number.	0
taskSchedulerType	Type of task scheduler to use.	_default
poissonRatio	FEM Poisson Ratio in Hooke's law [0,0.5[	0.45
youngModulus	FEM Young's Modulus in Hooke's law	5000
elementStiffness	List of stiffness matrices per element
rotationMethod	The method used to compute the element rotations. - stable_polar: Stable polar decomposition - polar: Polar decomposition - identity: Identity rotation. Equivalent to the linear small strain FEM.
Multithreading
computeForceStrategy	The compute strategy used to compute the forces. - parallel: The algorithm is executed in parallel - sequenced: The algorithm is executed sequentially
computeForceDerivStrategy	The compute strategy used to compute the forces derivatives. - parallel: The algorithm is executed in parallel - sequenced: The algorithm is executed sequentially
Visualization
elementSpace	When rendering, the space between elements	0.125

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

Vec3d,Hexahedron

Templates:

• Vec3d,Hexahedron

Target: Sofa.Component.SolidMechanics.FEM.Elastic

namespace: sofa::component::solidmechanics::fem::elastic

parents:

• BaseElementLinearFEMForceField
• FEMForceField

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
nbThreads	If not yet initialized, the main task scheduler is initialized with this number of threads. 0 corresponds to the number of available cores on the CPU. -n (minus) corresponds to the number of available cores on the CPU minus the provided number.	0
taskSchedulerType	Type of task scheduler to use.	_default
poissonRatio	FEM Poisson Ratio in Hooke's law [0,0.5[	0.45
youngModulus	FEM Young's Modulus in Hooke's law	5000
elementStiffness	List of stiffness matrices per element
rotationMethod	The method used to compute the element rotations. - stable_polar: Stable polar decomposition - polar: Polar decomposition - identity: Identity rotation. Equivalent to the linear small strain FEM. - hexahedron: Compute the rotation based on two average edges in the hexahedron
Multithreading
computeForceStrategy	The compute strategy used to compute the forces. - parallel: The algorithm is executed in parallel - sequenced: The algorithm is executed sequentially
computeForceDerivStrategy	The compute strategy used to compute the forces derivatives. - parallel: The algorithm is executed in parallel - sequenced: The algorithm is executed sequentially
Visualization
elementSpace	When rendering, the space between elements	0.125

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

Vec3d,Tetrahedron...

Templates:

• Vec3d,Tetrahedron
• Vec3d,Triangle

Target: Sofa.Component.SolidMechanics.FEM.Elastic

namespace: sofa::component::solidmechanics::fem::elastic

parents:

• BaseElementLinearFEMForceField
• FEMForceField

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
nbThreads	If not yet initialized, the main task scheduler is initialized with this number of threads. 0 corresponds to the number of available cores on the CPU. -n (minus) corresponds to the number of available cores on the CPU minus the provided number.	0
taskSchedulerType	Type of task scheduler to use.	_default
poissonRatio	FEM Poisson Ratio in Hooke's law [0,0.5[	0.45
youngModulus	FEM Young's Modulus in Hooke's law	5000
elementStiffness	List of stiffness matrices per element
rotationMethod	The method used to compute the element rotations. - stable_polar: Stable polar decomposition - polar: Polar decomposition - identity: Identity rotation. Equivalent to the linear small strain FEM. - triangle: Compute the rotation based on the Gram-Schmidt frame alignment
Multithreading
computeForceStrategy	The compute strategy used to compute the forces. - parallel: The algorithm is executed in parallel - sequenced: The algorithm is executed sequentially
computeForceDerivStrategy	The compute strategy used to compute the forces derivatives. - parallel: The algorithm is executed in parallel - sequenced: The algorithm is executed sequentially
Visualization
elementSpace	When rendering, the space between elements	0.125

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

Examples

CorotationalFEMForceField_tetra_cpu_gpu.scn

XMLPython

<?xml version="1.0" ?>
<Node name="root" gravity="0 -9 0" dt="0.02">
    <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.Iterative"/> <!-- Needed to use components [CGLinearSolver] -->  
    <RequiredPlugin pluginName="Sofa.Component.Mapping.Linear"/> <!-- Needed to use components [IdentityMapping] -->  
    <RequiredPlugin pluginName="Sofa.Component.Mass"/> <!-- Needed to use components [DiagonalMass] -->  
    <RequiredPlugin pluginName="Sofa.Component.ODESolver.Backward"/> <!-- Needed to use components [EulerImplicitSolver] -->  
    <RequiredPlugin pluginName="Sofa.Component.SolidMechanics.FEM.Elastic"/> <!-- Needed to use components [TetrahedronCorotationalFEMForceField] -->  
    <RequiredPlugin pluginName="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->  
    <RequiredPlugin pluginName="Sofa.Component.Topology.Container.Dynamic"/> <!-- Needed to use components [HexahedronSetTopologyContainer,HexahedronSetTopologyModifier,QuadSetTopologyContainer,QuadSetTopologyModifier] -->  
    <RequiredPlugin pluginName="Sofa.Component.Topology.Container.Grid"/> <!-- Needed to use components [RegularGridTopology] -->  
    <RequiredPlugin pluginName="Sofa.Component.Topology.Mapping"/> <!-- Needed to use components [Hexa2QuadTopologicalMapping] -->  
    <RequiredPlugin pluginName="Sofa.Component.Visual"/> <!-- Needed to use components [VisualStyle] -->  
    <RequiredPlugin pluginName="Sofa.GL.Component.Rendering3D"/> <!-- Needed to use components [OglModel] -->
    <RequiredPlugin pluginName="SofaCUDA"/> <!-- Needed to use components [OglModel] -->

    <VisualStyle displayFlags="showBehaviorModels showVisual" />

    <DefaultAnimationLoop />
    <DefaultVisualManagerLoop />

    <Node name="TetrahedronCorotationalFEMForceField-GPU-Green">
        <Node name="Beam">
            <RegularGridTopology name="grid" n="40 10 10" min="0 6 -2" max="16 10 2" />
            <TetrahedronSetTopologyContainer name="BeamTopo" />
            <TetrahedronSetTopologyModifier name="Modifier" />

            <Hexa2TetraTopologicalMapping input="@grid" output="@BeamTopo" />
        </Node>

        <Node name="Simulated">
            <EulerImplicitSolver name="cg_odesolver" rayleighStiffness="0.1" rayleighMass="0.1" />
            <CGLinearSolver iterations="20" name="linear solver" tolerance="1.0e-12" threshold="1.0e-12" />

            <MechanicalObject position="@../Beam/grid.position" name="Volume" template="CudaVec3f"/>

            <TetrahedronSetTopologyContainer name="Container" src="@../Beam/BeamTopo"/>

            <DiagonalMass totalMass="50.0" />
            <BoxROI name="ROI1" box="-0.1 5 -3 0.1 11 3" drawBoxes="1" />

            <FixedProjectiveConstraint indices="@ROI1.indices" />
            <TetrahedronCorotationalFEMForceField name="FEM" template="CudaVec3f" youngModulus="2000" poissonRatio="0.3" />
            <Node name="surface">
                <TriangleSetTopologyContainer name="Container" />
                <TriangleSetTopologyModifier name="Modifier" />
                <TriangleSetGeometryAlgorithms template="CudaVec3f" name="GeomAlgo" />

                <Tetra2TriangleTopologicalMapping input="@../Container" output="@Container" />
                <Node name="Visu">
                    <OglModel name="Visual" color="green" />
                    <IdentityMapping input="@../../Volume" output="@Visual" />
                </Node>
            </Node>
        </Node>  
    </Node>


    <Node name="TetrahedronCorotationalFEMForceField-CPU-red">
        <Node name="Beam">
            <RegularGridTopology name="grid" n="40 10 10" min="0 6 -2" max="16 10 2" />
            <TetrahedronSetTopologyContainer name="BeamTopo" />
            <TetrahedronSetTopologyModifier name="Modifier" />

            <Hexa2TetraTopologicalMapping input="@grid" output="@BeamTopo" />
        </Node>

        <Node name="Simulated">
            <EulerImplicitSolver name="cg_odesolver" rayleighStiffness="0.1" rayleighMass="0.1" />
            <CGLinearSolver iterations="20" name="linear solver" tolerance="1.0e-12" threshold="1.0e-12" />

            <MechanicalObject position="@../Beam/grid.position" name="Volume" template="Vec3d"/>

            <TetrahedronSetTopologyContainer name="Container" src="@../Beam/BeamTopo"/>

            <DiagonalMass totalMass="50.0" />
            <BoxROI name="ROI1" box="-0.1 5 -3 0.1 11 3" drawBoxes="1" />

            <FixedProjectiveConstraint indices="@ROI1.indices" />
            <TetrahedronCorotationalFEMForceField name="FEM" youngModulus="2000" poissonRatio="0.3" />
            <Node name="surface">
                <TriangleSetTopologyContainer name="Container" />
                <TriangleSetTopologyModifier name="Modifier" />
                <TriangleSetGeometryAlgorithms template="Vec3d" name="GeomAlgo" />

                <Tetra2TriangleTopologicalMapping input="@../Container" output="@Container" />
                <Node name="Visu">
                    <OglModel name="Visual" color="red" />
                    <IdentityMapping input="@../../Volume" output="@Visual" />
                </Node>
            </Node>
        </Node> 
    </Node>
</Node>

def createScene(root_node):

   root = root_node.addChild('root', gravity="0 -9 0", dt="0.02")

   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Constraint.Projective")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Engine.Select")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.LinearSolver.Iterative")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Mapping.Linear")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Mass")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.ODESolver.Backward")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.SolidMechanics.FEM.Elastic")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.StateContainer")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Topology.Container.Dynamic")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Topology.Container.Grid")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Topology.Mapping")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Visual")
   root.addObject('RequiredPlugin', pluginName="Sofa.GL.Component.Rendering3D")
   root.addObject('RequiredPlugin', pluginName="SofaCUDA")
   root.addObject('VisualStyle', displayFlags="showBehaviorModels showVisual")
   root.addObject('DefaultAnimationLoop', )
   root.addObject('DefaultVisualManagerLoop', )

   tetrahedron_corotational_fem_force_field__gpu__green = root.addChild('TetrahedronCorotationalFEMForceField-GPU-Green')

   beam = TetrahedronCorotationalFEMForceField-GPU-Green.addChild('Beam')

   beam.addObject('RegularGridTopology', name="grid", n="40 10 10", min="0 6 -2", max="16 10 2")
   beam.addObject('TetrahedronSetTopologyContainer', name="BeamTopo")
   beam.addObject('TetrahedronSetTopologyModifier', name="Modifier")
   beam.addObject('Hexa2TetraTopologicalMapping', input="@grid", output="@BeamTopo")

   simulated = TetrahedronCorotationalFEMForceField-GPU-Green.addChild('Simulated')

   simulated.addObject('EulerImplicitSolver', name="cg_odesolver", rayleighStiffness="0.1", rayleighMass="0.1")
   simulated.addObject('CGLinearSolver', iterations="20", name="linear solver", tolerance="1.0e-12", threshold="1.0e-12")
   simulated.addObject('MechanicalObject', position="@../Beam/grid.position", name="Volume", template="CudaVec3f")
   simulated.addObject('TetrahedronSetTopologyContainer', name="Container", src="@../Beam/BeamTopo")
   simulated.addObject('DiagonalMass', totalMass="50.0")
   simulated.addObject('BoxROI', name="ROI1", box="-0.1 5 -3 0.1 11 3", drawBoxes="1")
   simulated.addObject('FixedProjectiveConstraint', indices="@ROI1.indices")
   simulated.addObject('TetrahedronCorotationalFEMForceField', name="FEM", template="CudaVec3f", youngModulus="2000", poissonRatio="0.3")

   surface = Simulated.addChild('surface')

   surface.addObject('TriangleSetTopologyContainer', name="Container")
   surface.addObject('TriangleSetTopologyModifier', name="Modifier")
   surface.addObject('TriangleSetGeometryAlgorithms', template="CudaVec3f", name="GeomAlgo")
   surface.addObject('Tetra2TriangleTopologicalMapping', input="@../Container", output="@Container")

   visu = surface.addChild('Visu')

   visu.addObject('OglModel', name="Visual", color="green")
   visu.addObject('IdentityMapping', input="@../../Volume", output="@Visual")

   tetrahedron_corotational_fem_force_field__cpu_red = root.addChild('TetrahedronCorotationalFEMForceField-CPU-red')

   beam = TetrahedronCorotationalFEMForceField-CPU-red.addChild('Beam')

   beam.addObject('RegularGridTopology', name="grid", n="40 10 10", min="0 6 -2", max="16 10 2")
   beam.addObject('TetrahedronSetTopologyContainer', name="BeamTopo")
   beam.addObject('TetrahedronSetTopologyModifier', name="Modifier")
   beam.addObject('Hexa2TetraTopologicalMapping', input="@grid", output="@BeamTopo")

   simulated = TetrahedronCorotationalFEMForceField-CPU-red.addChild('Simulated')

   simulated.addObject('EulerImplicitSolver', name="cg_odesolver", rayleighStiffness="0.1", rayleighMass="0.1")
   simulated.addObject('CGLinearSolver', iterations="20", name="linear solver", tolerance="1.0e-12", threshold="1.0e-12")
   simulated.addObject('MechanicalObject', position="@../Beam/grid.position", name="Volume", template="Vec3d")
   simulated.addObject('TetrahedronSetTopologyContainer', name="Container", src="@../Beam/BeamTopo")
   simulated.addObject('DiagonalMass', totalMass="50.0")
   simulated.addObject('BoxROI', name="ROI1", box="-0.1 5 -3 0.1 11 3", drawBoxes="1")
   simulated.addObject('FixedProjectiveConstraint', indices="@ROI1.indices")
   simulated.addObject('TetrahedronCorotationalFEMForceField', name="FEM", youngModulus="2000", poissonRatio="0.3")

   surface = Simulated.addChild('surface')

   surface.addObject('TriangleSetTopologyContainer', name="Container")
   surface.addObject('TriangleSetTopologyModifier', name="Modifier")
   surface.addObject('TriangleSetGeometryAlgorithms', template="Vec3d", name="GeomAlgo")
   surface.addObject('Tetra2TriangleTopologicalMapping', input="@../Container", output="@Container")

   visu = surface.addChild('Visu')

   visu.addObject('OglModel', name="Visual", color="red")
   visu.addObject('IdentityMapping', input="@../../Volume", output="@Visual")