Beam collision mapping

Hello,

I’m trying to associate a collision model to connected beam elements (on which I used the BeamFEMForceField component). Ideally I would have associated the collision model directly to the topology and MechanicalObject of my beams, using the TLineModel component. However I believe that this component is not ‘instantiable’ on Rigid3d DOFs, which is the type of nodes used in the beam elements.

Consequently, I duplicated my DOFs and edge topology in a dedicated collision node. I successfully added the TLineModel component in the same node. Then I tried to use a mapping between the ‘Rigid3d’ MechanicalObject associated to the force field and the ‘Vec3d’ MechanicalObject corresponding to the collision model, but I encountered some difficulties.

– Trying with an IdentityMapping or a BarycentricMapping results in an error message at runtime:

[ERROR]   [InfoComponent(Not created (IdentityMapping))] Object type IdentityMapping<Rigid3d,Vec3d> was not created
The object is in the factory but cannot be created.
Requested template: Rigid3d,Vec3d(Rigid3d,Vec3d)
Available templates: Rigid2d,Rigid2d, Rigid2d,Vec2d, Rigid3d,ExtVec3d, Rigid3d,Rigid3d, Rigid3d,Vec3d, Vec1d,Vec1d, Vec2d,Vec2d, Vec3d,ExtVec3d, Vec3d,Vec3d, Vec6d,ExtVec3d, Vec6d,Vec3d, Vec6d,Vec6d,

[ERROR]   [SceneLoaderXML] Node initialization failed.

– Trying with the BeamLinearMapping component either generate the same error if I specify the template, input and output fields, or creates a collision model which seems to only be mapped to the first node of the beams, if I don’t specify anything.

NB: I found these topics on the forum, which could be related but where I couldn’t find a solution:

No collision between the collision models

Mapping between BeamFEMForceField behavioral model and oglmodel

Below is the scene file I’m using :

<Node name="root" dt="5e-4" gravity="0 -9.81 0" bbox="-1e-3 -1e-3 -1e-3 1e-3 1e-3 1e-3">

	<RequiredPlugin name="SofaMiscCollision"/>
    <CollisionPipeline verbose="0" depth="10" draw="0" />
    <BruteForceDetection name="N2" />
    <MinProximityIntersection name="Proximity" alarmDistance="5e-4" contactDistance="1e-4" />
    <CollisionResponse name="Response" response="default" />
    
	<VisualStyle name="visualStyle1"  displayFlags="showBehaviorModels showForceFields showCollisionModels" />
        
    <Node name="Object">
        <EulerImplicitSolver name="cg_odesolver"  printLog="0"  rayleighStiffness="0.1" rayleighMass="0.1" />
        <CGLinearSolver template="GraphScattered" name="linear solver"  iterations="25"  tolerance="1e-09"  threshold="1e-09" />
    
        <MechanicalObject template="Rigid3d" name="DoFs" position="0 1e-3 0 0 0 0 1
                                                                   1e-3 1e-3 0 0 0 0 1
                                                                   2e-3 1e-3 0 0 0 0 1
                                                                   3e-3 1e-3 0 0 0 0 1
                                                                   4e-3 1e-3 0 0 0 0 1" />
        <UniformMass name="uniformMass1" totalMass="1e-6" showAxisSizeFactor="1e-4"/>
        <MeshTopology lines="0 1 1 2 2 3 3 4" />
        <BeamFEMForceField template="Rigid3d" name="FF" radius="1e-4" poissonRatio="0.3" youngModulus="2e6" />
        
        <Node name="Collision model">
            <MechanicalObject template="Vec3d" name="collisionDoFs" position="0 1e-3 0 1e-3 1e-3 0 2e-3 1e-3 0 3e-3 1e-3 0 4e-3 1e-3 0" />
            <MeshTopology lines="0 1 1 2 2 3 3 4" />
            <TLineModel template="Vec3d"/>
            <TPointModel />
            <!-- <BeamLinearMapping isMechanical="true"/> -->
            <IdentityMapping template="Rigid3d,Vec3d" input="@../DoFs" output="@collisionDOFs"/>
            <!-- <BeamLinearMapping isMechanical="true" input="@../DoFs" output="@collisionDOFs"/> -->
            <!-- <BarycentricMapping template="Vec3d,Rigid3d" input="@../DoFs" output="@collisionDOFs"/> -->
        </Node>
    </Node>
    
    <Node name="Floor">
        <MeshObjLoader name="loader" filename="floor2b.obj" scale="1e-4" translation="0 10.245 0" />
        <Mesh src="@loader" />
        <MechanicalObject src="@loader" dy="-10.25" />
        <TTriangleModel name="T" simulated="0" moving="0" />
        <TLineModel name="L" simulated="0" moving="0" />
        <TPointModel name="P" simulated="0" moving="0" />
    </Node>

</Node>

I commented the lines corresponding to the different mapping scenarios I mentioned above.

Does anyone have a clue on what I am missing ?

Best regards,

Camille

PS: The mesh file I’m using for the ‘floor’ is part of the SOFA sources.
I’m using SOFA’s master version (commit 95d33bff from 12/02/2019), on Windows 10 64bits