Can the FixedConstraint component act on rigid bodies？

[yangwxb]

    <MechanicalObject name="instrumentState2" template="Rigid3d" translation = "0 0.005 0" rotation=" 0 0 0"/>
    <UniformMass name="Mass" totalMass="0.001" />
    <RestShapeSpringsForceField stiffness='300000' angularStiffness='300000000' external_rest_shape='@../Tool_3/DOFs1' points='0' external_points='0'/>
  
    <UncoupledConstraintCorrection useOdeSolverIntegrationFactors="0"/>
    <FixedConstraint name="FixedConstraint" indices="153 245 146 189 230 255 301"/>
    <Node name="VisuTool" >
        <MeshOBJLoader name="meshLoader_3" filename="D:\unity\test\Assets\SofaUnity\Scenes\SofaScenes\mesh\jiangZHunagtiK.obj" handleSeams="1" scale3d="0.31 0.31 0.31"/>
        <OglModel name="InstrumentVisualModel2" src="@meshLoader_3" color="red" />
        <RigidMapping name="VM->VM mapping" input="@instrumentState2" output="@InstrumentVisualModel2" /> 
    </Node>
    <Node name="CollisionModel" >
    <MeshOBJLoader filename="D:\unity\test\Assets\SofaUnity\Scenes\SofaScenes\mesh\jiangZHunagtiK.obj"  name="loader1" scale3d="0.31 0.31 0.31"/>
    <MeshTopology src="@loader1" name="InstrumentCollisionMode2" />
    <MechanicalObject src="@loader1" name="instrumentCollisionState2" />
    <TriangleCollisionModel name="triangleCol" bothSide="true" />
    <LineCollisionModel contactStiffness="10" />			
    <PointCollisionModel contactStiffness="10"/>
    <RigidMapping name="MM->CM mapping" input="@instrumentState2" output="@instrumentCollisionState2" />		
    </Node> 
</Node>

[yangwxb]

As mentioned in the title, I tried to use FixedConstraint to bind a rigid body, but it failed. What is the cause？

[hugtalbot]

Hi @yangwxb

Yes FixedConstraint (recently renamed FixedProjectiveConstraint in v24.06) works with rigid bodies

It appears that the indices you provide are not valid.
What's the size of the position data in the rigid MechanicalObject?

[github-actions[bot]]

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@yangwxb
Feedback has been given to you by the project reviewers, however we have not received a response from you. Without further news in the coming weeks, this discussion will be automatically closed in order to keep this forum clean and fresh 🌱 Thank you for your understanding

[github-actions[bot]]

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@yangwxb
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