EulerExplicitIntegrationScheme

A simple explicit time integrator.

Target: Sofa.Component.IntegrationScheme.Forward

namespace: sofa::component::integrationscheme::forward

parents:

• ExplicitIntegrationScheme

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
symplectic	If true (default), the velocities are updated before the positions and the method is symplectic, more robust. If false, the positions are updated before the velocities (standard Euler, less robust).	1
threadSafeVisitor	If true, do not use realloc and free visitors in fwdInteractionForceField.	0

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
linearSolver	Linear IntegrationScheme used by this component	LinearSolver

Examples

EulerExplicitIntegrationScheme.scn

XMLPython

<!--
This scene shows an example of a forward Euler integration scheme.
This is the variant of the component EulerExplicitIntegrationScheme where the Data
'symplectic' is set to false (true by default).
In this example, the mass is not diagonal. Since it cannot be inverted
trivially, it requires a linear solver, here SparseLDLSolver.
-->

<Node name="root" gravity="0 -9.81 0" dt="0.00001">
    <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.IO.Mesh"/> <!-- Needed to use components [MeshOBJLoader] -->
    <RequiredPlugin pluginName="Sofa.Component.LinearSolver.Direct"/> <!-- Needed to use components [SparseLDLSolver] -->
    <RequiredPlugin pluginName="Sofa.Component.Mapping.Linear"/> <!-- Needed to use components [IdentityMapping] -->
    <RequiredPlugin pluginName="Sofa.Component.Mass"/> <!-- Needed to use components [MeshMatrixMass] -->
    <RequiredPlugin pluginName="Sofa.Component.IntegrationScheme.Forward"/> <!-- Needed to use components [EulerExplicitIntegrationScheme] -->
    <RequiredPlugin pluginName="Sofa.Component.SolidMechanics.Spring"/> <!-- Needed to use components [MeshSpringForceField] -->
    <RequiredPlugin pluginName="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
    <RequiredPlugin pluginName="Sofa.Component.Topology.Container.Dynamic"/> <!-- Needed to use components [HexahedronSetGeometryAlgorithms 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] -->
    <DefaultAnimationLoop/>

    <VisualStyle displayFlags="showBehaviorModels showForceFields" />

    <Node name="DeformableObject">

        <EulerExplicitIntegrationScheme name="odeExplicitSolver" symplectic="false"/>
        <SparseLDLSolver />

        <MechanicalObject name="dofs"/>

        <RegularGridTopology name="topology" nx="4" ny="4" nz="11" xmin="-1.5" xmax="1.5" ymin="-1.5" ymax="1.5" zmin="0" zmax="10" />
        <HexahedronSetGeometryAlgorithms/>
        <MeshMatrixMass totalMass="15"/>

        <BoxROI box="-1.5 -1.5 0 1.5 1.5 0.0001" name="box"/>
        <FixedProjectiveConstraint indices="@box.indices" />
        <MeshSpringForceField stiffness="3E2"/>

        <Node name="visual">
            <QuadSetTopologyContainer  name="Container" />
            <QuadSetTopologyModifier/>
            <Hexa2QuadTopologicalMapping input="@../topology" output="@Container" />
            <OglModel name="Visual" color="yellow" quads="@Container.quads" />
            <IdentityMapping input="@../dofs" output="@Visual" />
        </Node>

    </Node>

    <Node name="floor-visual">
        <MeshOBJLoader name="meshLoader" filename="mesh/floorFlat.obj" scale3d="0.5 0.5 0.5"/>
        <OglModel src="@meshLoader" dy="-8" dz="10"/>
        <OglModel src="@meshLoader" rx="90" dy="2"/>
    </Node>
</Node>

def createScene(root_node):

   root = root_node.addChild('root', gravity="0 -9.81 0", dt="0.00001")

   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Constraint.Projective")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Engine.Select")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.IO.Mesh")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.LinearSolver.Direct")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Mapping.Linear")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Mass")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.IntegrationScheme.Forward")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.SolidMechanics.Spring")
   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('DefaultAnimationLoop', )
   root.addObject('VisualStyle', displayFlags="showBehaviorModels showForceFields")

   deformable_object = root.addChild('DeformableObject')

   deformable_object.addObject('EulerExplicitIntegrationScheme', name="odeExplicitSolver", symplectic="false")
   deformable_object.addObject('SparseLDLSolver', )
   deformable_object.addObject('MechanicalObject', name="dofs")
   deformable_object.addObject('RegularGridTopology', name="topology", nx="4", ny="4", nz="11", xmin="-1.5", xmax="1.5", ymin="-1.5", ymax="1.5", zmin="0", zmax="10")
   deformable_object.addObject('HexahedronSetGeometryAlgorithms', )
   deformable_object.addObject('MeshMatrixMass', totalMass="15")
   deformable_object.addObject('BoxROI', box="-1.5 -1.5 0 1.5 1.5 0.0001", name="box")
   deformable_object.addObject('FixedProjectiveConstraint', indices="@box.indices")
   deformable_object.addObject('MeshSpringForceField', stiffness="3E2")

   visual = DeformableObject.addChild('visual')

   visual.addObject('QuadSetTopologyContainer', name="Container")
   visual.addObject('QuadSetTopologyModifier', )
   visual.addObject('Hexa2QuadTopologicalMapping', input="@../topology", output="@Container")
   visual.addObject('OglModel', name="Visual", color="yellow", quads="@Container.quads")
   visual.addObject('IdentityMapping', input="@../dofs", output="@Visual")

   floor_visual = root.addChild('floor-visual')

   floor_visual.addObject('MeshOBJLoader', name="meshLoader", filename="mesh/floorFlat.obj", scale3d="0.5 0.5 0.5")
   floor_visual.addObject('OglModel', src="@meshLoader", dy="-8", dz="10")
   floor_visual.addObject('OglModel', src="@meshLoader", rx="90", dy="2")

EulerExplicitIntegrationScheme_diagonal.scn

XMLPython

<!--
This scene shows an example of a forward Euler integration scheme.
This is the variant of the component EulerExplicitIntegrationScheme where the Data
'symplectic' is set to false (true by default).
In this example, the mass is diagonal. Since it can be inverted
trivially, it does not require a linear solver.
-->

<Node name="root" gravity="0 -9.81 0" dt="0.00001">
    <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.IO.Mesh"/> <!-- Needed to use components [MeshOBJLoader] -->
    <RequiredPlugin pluginName="Sofa.Component.Mapping.Linear"/> <!-- Needed to use components [IdentityMapping] -->
    <RequiredPlugin pluginName="Sofa.Component.Mass"/> <!-- Needed to use components [UniformMass] -->
    <RequiredPlugin pluginName="Sofa.Component.IntegrationScheme.Forward"/> <!-- Needed to use components [EulerExplicitIntegrationScheme] -->
    <RequiredPlugin pluginName="Sofa.Component.SolidMechanics.Spring"/> <!-- Needed to use components [MeshSpringForceField] -->
    <RequiredPlugin pluginName="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
    <RequiredPlugin pluginName="Sofa.Component.Topology.Container.Dynamic"/> <!-- Needed to use components [HexahedronSetGeometryAlgorithms 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] -->
    <DefaultAnimationLoop/>
    <VisualStyle displayFlags="showBehaviorModels showForceFields" />

    <Node name="DeformableObject">

        <!-- Matrix system is diagonal because integration is explicit and Mass is diagonal -->
        <!-- No need for a LinearSolver -->
        <EulerExplicitIntegrationScheme name="odeExplicitSolver" symplectic="false"/>

        <MechanicalObject name="dofs"/>

        <RegularGridTopology name="topology" nx="4" ny="4" nz="11" xmin="-1.5" xmax="1.5" ymin="-1.5" ymax="1.5" zmin="0" zmax="10" />
        <HexahedronSetGeometryAlgorithms/>
        <UniformMass totalMass="15"/>

        <BoxROI box="-1.5 -1.5 0 1.5 1.5 0.0001" name="box"/>
        <FixedProjectiveConstraint indices="@box.indices" />
        <MeshSpringForceField stiffness="3E2"/>

        <Node name="visual">
            <QuadSetTopologyContainer  name="Container" />
            <QuadSetTopologyModifier/>
            <Hexa2QuadTopologicalMapping input="@../topology" output="@Container" />
            <OglModel name="Visual" color="yellow" quads="@Container.quads" />
            <IdentityMapping input="@../dofs" output="@Visual" />
        </Node>

    </Node>

    <Node name="floor-visual">
        <MeshOBJLoader name="meshLoader" filename="mesh/floorFlat.obj" scale3d="0.5 0.5 0.5"/>
        <OglModel src="@meshLoader" dy="-8" dz="10"/>
        <OglModel src="@meshLoader" rx="90" dy="2"/>
    </Node>
</Node>

def createScene(root_node):

   root = root_node.addChild('root', gravity="0 -9.81 0", dt="0.00001")

   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Constraint.Projective")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Engine.Select")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.IO.Mesh")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Mapping.Linear")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.Mass")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.IntegrationScheme.Forward")
   root.addObject('RequiredPlugin', pluginName="Sofa.Component.SolidMechanics.Spring")
   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('DefaultAnimationLoop', )
   root.addObject('VisualStyle', displayFlags="showBehaviorModels showForceFields")

   deformable_object = root.addChild('DeformableObject')

   deformable_object.addObject('EulerExplicitIntegrationScheme', name="odeExplicitSolver", symplectic="false")
   deformable_object.addObject('MechanicalObject', name="dofs")
   deformable_object.addObject('RegularGridTopology', name="topology", nx="4", ny="4", nz="11", xmin="-1.5", xmax="1.5", ymin="-1.5", ymax="1.5", zmin="0", zmax="10")
   deformable_object.addObject('HexahedronSetGeometryAlgorithms', )
   deformable_object.addObject('UniformMass', totalMass="15")
   deformable_object.addObject('BoxROI', box="-1.5 -1.5 0 1.5 1.5 0.0001", name="box")
   deformable_object.addObject('FixedProjectiveConstraint', indices="@box.indices")
   deformable_object.addObject('MeshSpringForceField', stiffness="3E2")

   visual = DeformableObject.addChild('visual')

   visual.addObject('QuadSetTopologyContainer', name="Container")
   visual.addObject('QuadSetTopologyModifier', )
   visual.addObject('Hexa2QuadTopologicalMapping', input="@../topology", output="@Container")
   visual.addObject('OglModel', name="Visual", color="yellow", quads="@Container.quads")
   visual.addObject('IdentityMapping', input="@../dofs", output="@Visual")

   floor_visual = root.addChild('floor-visual')

   floor_visual.addObject('MeshOBJLoader', name="meshLoader", filename="mesh/floorFlat.obj", scale3d="0.5 0.5 0.5")
   floor_visual.addObject('OglModel', src="@meshLoader", dy="-8", dz="10")
   floor_visual.addObject('OglModel', src="@meshLoader", rx="90", dy="2")