ROI defined by a complex mesh

[zbounik]

Hi,

Is there any way to define ROI not by a box/plane/sphereROI but by using a more complex mesh?

Zahra

[hugtalbot]

Hi @zbounik !
You can find an example of a MeshROI here.
Else I recently made a tutorial about this online: https://www.youtube.com/watch?v=52JSucavJhI&list=PLL2-UDGHPj0iLCieVkrv3OvAme0jsWl91

[zbounik]

Ah! Thanks. Wondering why I didn't notice that in the scene examples.

[damienmarchal]

Hi @zbounik,

I think you can use the MeshROI component.

EDIT: @hugtalbot was faster than me ;)

[zbounik]

Hi again,

I am trying to use MeshROI as you suggest but I don't get what I want. i am not sure if I am doing anything wrong? (I want to get the part of the white mesh that is inside the yellow one as the region of interest):

<Node name="root" gravity="0 -9.81 0" dt="0.02">
    <RequiredPlugin name="SofaOpenglVisual"/>
    <VisualStyle displayFlags="showForceFields" />
    <DefaultPipeline name="CollisionPipeline" verbose="0" />
    <BruteForceBroadPhase/>
    <BVHNarrowPhase/>
    <DefaultContactManager name="collision response" response="PenalityContactForceField" />
    <DiscreteIntersection />
    <Node name="LiverFEM" gravity="0 -9.81 0">
        <!--<EulerImplicitSolver name="cg_odesolver" printLog="0"  rayleighStiffness="0.1" rayleighMass="0.1" />-->
        <CGLinearSolver name="linear solver" iterations="25" tolerance="1e-09" threshold="1e-09" />
        <MeshOBJLoader name="meshLoader0" filename="mesh/liver.obj" />
        <TriangleSetTopologyContainer name="mesh" src="@meshLoader0" />
        <!--<MeshTopology name="mesh" src="@meshLoader0" />-->
        <MechanicalObject template="Vec3d" name="mecaObj"/>
        <!--<TetrahedronFEMForceField template="Vec3d" name="FEM" youngModulus="50" poissonRatio="0.45" />-->
        <UniformMass name="mass" totalMass="1" />
        <OglModel name="VisualModel" color="1.0 1.0 1.0 0.5" />
        <BarycentricMapping name="visualmapping" input="@mecaObj" output="@VisualModel" />
    </Node>

    <Node name="MeshROI"  >
        <MeshOBJLoader name="ROIloader" filename="mesh/liver.obj" translation="3 0 0"/>
        <MechanicalObject template="Vec3d" name="mecaObj2"/>
        <TriangleSetTopologyContainer name="mesh2" src="@ROIloader" />
        <OglModel name="VisualModel2" color="1.0 1.0 0.2 0.5"/>
        <MeshROI name="ROIm"  drawMesh="1" drawBox="1" drawEdges="0" drawTriangles="1" drawTetrahedra="1" drawOut="1" computeMeshROI="1"  doUpdate="0"
           position="@../LiverFEM/mecaObj.position" triangles="@../LiverFEM/mecaObj.triangles" ROIposition="@ROIloader.position" ROItriangles="@ROIloader.triangles" />
        <FixedConstraint indices="ROIm.indices" />

    </Node> 
</Node>

[hugtalbot]

Hi @zbounik

This works fine for me using these surface meshes:

my scene:

<Node name="root" gravity="0 -9.81 0" dt="0.02">
    <RequiredPlugin name="SofaOpenglVisual"/>
    <VisualStyle displayFlags="showForceFields" />
    <DefaultPipeline name="CollisionPipeline" verbose="0" />
    <BruteForceBroadPhase/>
    <BVHNarrowPhase/>
    <DefaultContactManager name="collision response" response="PenalityContactForceField" />
    <DiscreteIntersection />
    <Node name="LiverFEM" gravity="0 -9.81 0">
        <!--<EulerImplicitSolver name="cg_odesolver" printLog="0"  rayleighStiffness="0.1" rayleighMass="0.1" />-->
        <CGLinearSolver name="linear solver" iterations="25" tolerance="1e-09" threshold="1e-09" />
        <MeshOBJLoader name="meshLoader0" filename="mesh/liver.obj" />
        <TriangleSetTopologyContainer name="mesh" src="@meshLoader0" />
        <!--<MeshTopology name="mesh" src="@meshLoader0" />-->
        <MechanicalObject template="Vec3d" name="mecaObj"/>
        <!--<TetrahedronFEMForceField template="Vec3d" name="FEM" youngModulus="50" poissonRatio="0.45" />-->
        <UniformMass name="mass" totalMass="1" />
        <OglModel name="VisualModel" color="1.0 1.0 1.0 0.5" />
        <BarycentricMapping name="visualmapping" input="@mecaObj" output="@VisualModel" />
    </Node>

    <Node name="MeshROI"  >
        <MeshOBJLoader name="ROIloader" filename="mesh/liver.obj" translation="3 0 0"/>
        <MechanicalObject template="Vec3d" name="mecaObj2"/>
        <TriangleSetTopologyContainer name="mesh2" src="@ROIloader" />
        <OglModel name="VisualModel2" color="1.0 1.0 0.2 0.5"/>
        <MeshROI name="ROIm"  drawMesh="0" drawBox="1" drawEdges="0" drawTriangles="1" drawTetrahedra="0" drawOut="0" computeMeshROI="1"  doUpdate="0" drawSize="0.8"
           position="@../LiverFEM/mecaObj.position" triangles="@../LiverFEM/mecaObj.triangles" ROIposition="@ROIloader.position" ROItriangles="@ROIloader.triangles" />
        <FixedConstraint indices="ROIm.indices" />

    </Node> 
</Node>
```

[zbounik]

Thank you, my mistake was that I was assuming drawOUT as the output (selected region) of MeshROI.