MultiStepAnimationLoop

This component belongs to the category of AnimationLoop.

The MultiStepAnimationLoop derives from the DefaultAnimationLoop. This animation loop is different due to the fact that it allows - at each iteration - for running several collision (collisionSteps), and within each of these collision steps, several integration sub-steps can be computes (integrationSteps).

Data

The MultiStepAnimationLoop has the following data:

• collisionSteps: the number of collision steps computed within one time step
• integrationSteps: the number of time integration (time sub-steps involving the physics resolution) computed within one time step
• computeBoundingBox: a boolean defining whether the global bounding box of the scene is computed at each time step. Used mostly for rendering.

Usage

The MultiStepAnimationLoop has no pre-requisite.

Note that this MultiStepAnimationLoop does not handle constraints solved using Lagrange multipliers.

Example

This component is used as follows in XML format:

<MultiStepAnimationLoop collisionSteps="10" integrationSteps="2" />

or using SofaPython3:

node.addObject('MultiStepAnimationLoop', collisionSteps='10', integrationSteps='2')

An example scene involving a MultiStepAnimationLoop is available in examples/Component/AnimationLoop/MultiStepAnimationLoop.scn

Target: Sofa.Component.AnimationLoop

namespace: sofa::component::animationloop

parents:

• BaseAnimationLoop

Data:

Name	Description	Default value
name	object name	unnamed
printLog	if true, emits extra messages at runtime.	0
tags	list of the subsets the objet 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
computeBoundingBox	If true, compute the global bounding box of the scene at each time step. Used mostly for rendering.	1
collisionSteps	number of collision steps between each frame rendering	1
integrationSteps	number of integration steps between each collision detection	1

Links:

Name	Description
context	Graph Node containing this object (or BaseContext::getDefault() if no graph is used)
slaves	Sub-objects used internally by this object
master	nullptr for regular objects, or master object for which this object is one sub-objects
targetNode	Link to the scene's node that will be processed by the loop

Examples

Component/AnimationLoop/MultiStepAnimationLoop.scn

XMLPython

<?xml version="1.0" ?>
<Node name="root" dt="1.0">
    <RequiredPlugin name="Sofa.Component.AnimationLoop"/> <!-- Needed to use components [MultiStepAnimationLoop] -->
    <RequiredPlugin name="Sofa.Component.Collision.Detection.Algorithm"/> <!-- Needed to use components [BVHNarrowPhase BruteForceBroadPhase CollisionPipeline] -->
    <RequiredPlugin name="Sofa.Component.Collision.Detection.Intersection"/> <!-- Needed to use components [NewProximityIntersection] -->
    <RequiredPlugin name="Sofa.Component.Collision.Geometry"/> <!-- Needed to use components [TriangleCollisionModel] -->
    <RequiredPlugin name="Sofa.Component.Collision.Response.Contact"/> <!-- Needed to use components [CollisionResponse] -->
    <RequiredPlugin name="Sofa.Component.IO.Mesh"/> <!-- Needed to use components [MeshOBJLoader] -->
    <RequiredPlugin name="Sofa.Component.LinearSolver.Iterative"/> <!-- Needed to use components [CGLinearSolver] -->
    <RequiredPlugin name="Sofa.Component.Mapping.NonLinear"/> <!-- Needed to use components [RigidMapping] -->
    <RequiredPlugin name="Sofa.Component.Mass"/> <!-- Needed to use components [UniformMass] -->
    <RequiredPlugin name="Sofa.Component.ODESolver.Backward"/> <!-- Needed to use components [EulerImplicitSolver] -->
    <RequiredPlugin name="Sofa.Component.StateContainer"/> <!-- Needed to use components [MechanicalObject] -->
    <RequiredPlugin name="Sofa.Component.Topology.Container.Constant"/> <!-- Needed to use components [MeshTopology] -->
    <RequiredPlugin name="Sofa.GL.Component.Rendering3D"/> <!-- Needed to use components [OglModel] -->

    <CollisionPipeline depth="6" verbose="0" draw="0" />
    <BruteForceBroadPhase/>
    <BVHNarrowPhase/>
    <NewProximityIntersection name="Proximity" alarmDistance="0.3" contactDistance="0.2" />
    <CollisionResponse name="Response" response="PenalityContactForceField" />
    <MultiStepAnimationLoop collisionSteps="10" integrationSteps="2" />
    <Node name="ChainRigid">
        <Node name="TorusFixed">
            <MeshOBJLoader name="loader" filename="mesh/torus2_for_collision.obj" />
            <MeshTopology src="@loader" />
            <MechanicalObject src="@loader" />
            <TriangleCollisionModel simulated="0" moving="0" />
            <MeshOBJLoader name="meshLoader_4" filename="mesh/torus2.obj" handleSeams="1" />
            <OglModel name="Visual" src="@meshLoader_4" color="gray" />
        </Node>
        <Node name="TorusRigid-1">
            <EulerImplicitSolver  rayleighStiffness="0.1" rayleighMass="0.1" />
            <CGLinearSolver iterations="25" threshold="0.000000000001" tolerance="0.000001" />
            <MechanicalObject template="Rigid3" dx="2.5" />
            <UniformMass />
            <Node name="Visu">
                <MeshOBJLoader name="meshLoader_3" filename="mesh/torus.obj" handleSeams="1" />
                <OglModel name="Visual" src="@meshLoader_3" color="gray" />
                <RigidMapping input="@.." output="@Visual" />
            </Node>
            <Node name="Surf2">
                <MeshOBJLoader name="loader" filename="mesh/torus_for_collision.obj" />
                <MeshTopology src="@loader" />
                <MechanicalObject src="@loader" />
                <TriangleCollisionModel />
                <RigidMapping />
            </Node>
        </Node>
        <Node name="TorusRigid-2">
            <EulerImplicitSolver />
            <CGLinearSolver iterations="25" threshold="0.000000000001" tolerance="0.000001" />
            <MechanicalObject template="Rigid3" dx="5" />
            <UniformMass />
            <Node name="Visu">
                <MeshOBJLoader name="meshLoader_0" filename="mesh/torus2.obj" handleSeams="1" />
                <OglModel name="Visual" src="@meshLoader_0" color="gray" />
                <RigidMapping input="@.." output="@Visual" />
            </Node>
            <Node name="Surf2">
                <MeshOBJLoader name="loader" filename="mesh/torus2_for_collision.obj" />
                <MeshTopology src="@loader" />
                <MechanicalObject src="@loader" />
                <TriangleCollisionModel />
                <RigidMapping />
            </Node>
        </Node>
        <Node name="TorusRigid-3">
            <EulerImplicitSolver />
            <CGLinearSolver iterations="25" threshold="0.000000000001" tolerance="0.000001" />
            <MechanicalObject template="Rigid3" dx="7.5" />
            <UniformMass />
            <Node name="Visu">
                <MeshOBJLoader name="meshLoader_1" filename="mesh/torus.obj" handleSeams="1" />
                <OglModel name="Visual" src="@meshLoader_1" color="gray" />
                <RigidMapping input="@.." output="@Visual" />
            </Node>
            <Node name="Surf2">
                <MeshOBJLoader name="loader" filename="mesh/torus_for_collision.obj" />
                <MeshTopology src="@loader" />
                <MechanicalObject src="@loader" />
                <TriangleCollisionModel />
                <RigidMapping />
            </Node>
        </Node>
        <Node name="TorusRigid-4">
            <EulerImplicitSolver />
            <CGLinearSolver iterations="25" threshold="0.000000000001" tolerance="0.000001" />
            <MechanicalObject template="Rigid3" dx="10" />
            <UniformMass />
            <Node name="Visu">
                <MeshOBJLoader name="meshLoader_2" filename="mesh/torus2.obj" handleSeams="1" />
                <OglModel name="Visual" src="@meshLoader_2" color="gray" />
                <RigidMapping input="@.." output="@Visual" />
            </Node>
            <Node name="Surf2">
                <MeshOBJLoader name="loader" filename="mesh/torus2_for_collision.obj" />
                <MeshTopology src="@loader" />
                <MechanicalObject src="@loader" />
                <TriangleCollisionModel />
                <RigidMapping />
            </Node>
        </Node>
    </Node>
</Node>

def createScene(rootNode):

    root = rootNode.addChild('root', dt="1.0")
    root.addObject('RequiredPlugin', name="Sofa.Component.AnimationLoop")
    root.addObject('RequiredPlugin', name="Sofa.Component.Collision.Detection.Algorithm")
    root.addObject('RequiredPlugin', name="Sofa.Component.Collision.Detection.Intersection")
    root.addObject('RequiredPlugin', name="Sofa.Component.Collision.Geometry")
    root.addObject('RequiredPlugin', name="Sofa.Component.Collision.Response.Contact")
    root.addObject('RequiredPlugin', name="Sofa.Component.IO.Mesh")
    root.addObject('RequiredPlugin', name="Sofa.Component.LinearSolver.Iterative")
    root.addObject('RequiredPlugin', name="Sofa.Component.Mapping.NonLinear")
    root.addObject('RequiredPlugin', name="Sofa.Component.Mass")
    root.addObject('RequiredPlugin', name="Sofa.Component.ODESolver.Backward")
    root.addObject('RequiredPlugin', name="Sofa.Component.StateContainer")
    root.addObject('RequiredPlugin', name="Sofa.Component.Topology.Container.Constant")
    root.addObject('RequiredPlugin', name="Sofa.GL.Component.Rendering3D")
    root.addObject('CollisionPipeline', depth="6", verbose="0", draw="0")
    root.addObject('BruteForceBroadPhase')
    root.addObject('BVHNarrowPhase')
    root.addObject('NewProximityIntersection', name="Proximity", alarmDistance="0.3", contactDistance="0.2")
    root.addObject('CollisionResponse', name="Response", response="PenalityContactForceField")
    root.addObject('MultiStepAnimationLoop', collisionSteps="10", integrationSteps="2")

    ChainRigid = root.addChild('ChainRigid')

    TorusFixed = ChainRigid.addChild('TorusFixed')
    TorusFixed.addObject('MeshOBJLoader', name="loader", filename="mesh/torus2_for_collision.obj")
    TorusFixed.addObject('MeshTopology', src="@loader")
    TorusFixed.addObject('MechanicalObject', src="@loader")
    TorusFixed.addObject('TriangleCollisionModel', simulated="0", moving="0")
    TorusFixed.addObject('MeshOBJLoader', name="meshLoader_4", filename="mesh/torus2.obj", handleSeams="1")
    TorusFixed.addObject('OglModel', name="Visual", src="@meshLoader_4", color="gray")

    TorusRigid-1 = ChainRigid.addChild('TorusRigid-1')
    TorusRigid-1.addObject('EulerImplicitSolver', rayleighStiffness="0.1", rayleighMass="0.1")
    TorusRigid-1.addObject('CGLinearSolver', iterations="25", threshold="0.000000000001", tolerance="0.000001")
    TorusRigid-1.addObject('MechanicalObject', template="Rigid3", dx="2.5")
    TorusRigid-1.addObject('UniformMass')

    Visu = TorusRigid-1.addChild('Visu')
    Visu.addObject('MeshOBJLoader', name="meshLoader_3", filename="mesh/torus.obj", handleSeams="1")
    Visu.addObject('OglModel', name="Visual", src="@meshLoader_3", color="gray")
    Visu.addObject('RigidMapping', input="@..", output="@Visual")

    Surf2 = TorusRigid-1.addChild('Surf2')
    Surf2.addObject('MeshOBJLoader', name="loader", filename="mesh/torus_for_collision.obj")
    Surf2.addObject('MeshTopology', src="@loader")
    Surf2.addObject('MechanicalObject', src="@loader")
    Surf2.addObject('TriangleCollisionModel')
    Surf2.addObject('RigidMapping')

    TorusRigid-2 = ChainRigid.addChild('TorusRigid-2')
    TorusRigid-2.addObject('EulerImplicitSolver')
    TorusRigid-2.addObject('CGLinearSolver', iterations="25", threshold="0.000000000001", tolerance="0.000001")
    TorusRigid-2.addObject('MechanicalObject', template="Rigid3", dx="5")
    TorusRigid-2.addObject('UniformMass')

    Visu = TorusRigid-2.addChild('Visu')
    Visu.addObject('MeshOBJLoader', name="meshLoader_0", filename="mesh/torus2.obj", handleSeams="1")
    Visu.addObject('OglModel', name="Visual", src="@meshLoader_0", color="gray")
    Visu.addObject('RigidMapping', input="@..", output="@Visual")

    Surf2 = TorusRigid-2.addChild('Surf2')
    Surf2.addObject('MeshOBJLoader', name="loader", filename="mesh/torus2_for_collision.obj")
    Surf2.addObject('MeshTopology', src="@loader")
    Surf2.addObject('MechanicalObject', src="@loader")
    Surf2.addObject('TriangleCollisionModel')
    Surf2.addObject('RigidMapping')

    TorusRigid-3 = ChainRigid.addChild('TorusRigid-3')
    TorusRigid-3.addObject('EulerImplicitSolver')
    TorusRigid-3.addObject('CGLinearSolver', iterations="25", threshold="0.000000000001", tolerance="0.000001")
    TorusRigid-3.addObject('MechanicalObject', template="Rigid3", dx="7.5")
    TorusRigid-3.addObject('UniformMass')

    Visu = TorusRigid-3.addChild('Visu')
    Visu.addObject('MeshOBJLoader', name="meshLoader_1", filename="mesh/torus.obj", handleSeams="1")
    Visu.addObject('OglModel', name="Visual", src="@meshLoader_1", color="gray")
    Visu.addObject('RigidMapping', input="@..", output="@Visual")

    Surf2 = TorusRigid-3.addChild('Surf2')
    Surf2.addObject('MeshOBJLoader', name="loader", filename="mesh/torus_for_collision.obj")
    Surf2.addObject('MeshTopology', src="@loader")
    Surf2.addObject('MechanicalObject', src="@loader")
    Surf2.addObject('TriangleCollisionModel')
    Surf2.addObject('RigidMapping')

    TorusRigid-4 = ChainRigid.addChild('TorusRigid-4')
    TorusRigid-4.addObject('EulerImplicitSolver')
    TorusRigid-4.addObject('CGLinearSolver', iterations="25", threshold="0.000000000001", tolerance="0.000001")
    TorusRigid-4.addObject('MechanicalObject', template="Rigid3", dx="10")
    TorusRigid-4.addObject('UniformMass')

    Visu = TorusRigid-4.addChild('Visu')
    Visu.addObject('MeshOBJLoader', name="meshLoader_2", filename="mesh/torus2.obj", handleSeams="1")
    Visu.addObject('OglModel', name="Visual", src="@meshLoader_2", color="gray")
    Visu.addObject('RigidMapping', input="@..", output="@Visual")

    Surf2 = TorusRigid-4.addChild('Surf2')
    Surf2.addObject('MeshOBJLoader', name="loader", filename="mesh/torus2_for_collision.obj")
    Surf2.addObject('MeshTopology', src="@loader")
    Surf2.addObject('MechanicalObject', src="@loader")
    Surf2.addObject('TriangleCollisionModel')
    Surf2.addObject('RigidMapping')