How can I load my own.msh file in CubeCarving?

[CherryJGit]

I noticed that there is an example named CubeCarving in SofaUnity. I examined the scn file and found that it first generates hexahedrons internally and then converts them into a tetrahedral topology. I attempted to modify it to directly load my tetrahedral model in the form of an msh file. However, I encountered an issue with the topology. Therefore, I would like to ask how to modify this file to load my own tetrahedral model.

<DefaultAnimationLoop />
<CollisionPipeline verbose="0" />
<BruteForceBroadPhase/>
<BVHNarrowPhase/>
<CollisionResponse response="PenalityContactForceField" />
<MinProximityIntersection name="Proximity" alarmDistance="1.0" contactDistance="0.2" />

<EulerImplicitSolver name="EulerImplicit"  rayleighStiffness="0.1" rayleighMass="0.1" />
<CGLinearSolver name="CG Solver" iterations="25" tolerance="1e-9" threshold="1e-9"/>

<CarvingManager name="ACarving" active="0" carvingDistance="0.4" />

<Node name="carvingElement">
    <MechanicalObject name="Particles" template="Vec3d" position="5 15 5" velocity="0 0 0"/>
    <UniformMass name="Mass" totalMass="10.0" />
    <SphereCollisionModel name="tool" radius="0.1" tags="CarvingTool"/>
</Node>

<Node name="Hexa2Tetra" >
    <RegularGridTopology name="HexaTop" n="11 11 11" min="0 0 0" max="10 10 10" />
    <MechanicalObject name="cube" position="@HexaTop.position" />
    <TetrahedronSetTopologyContainer name="Container" position="@HexaTop.position" />
    <TetrahedronSetTopologyModifier name="Modifier"/>
    <Hexa2TetraTopologicalMapping input="@HexaTop" output="@Container" swapping="false" />
</Node>

<Node name="Cube">
    <MechanicalObject position="@../Hexa2Tetra/Container.position" name="Volume" />

    <TetrahedronSetTopologyContainer name="Tetra_topo" src="@../Hexa2Tetra/Container" />
    <TetrahedronSetTopologyModifier name="Modifier" />
    <TetrahedronSetGeometryAlgorithms name="GeomAlgo" template="Vec3d" drawTetrahedra="0" drawScaleTetrahedra="0.8"/>

    <DiagonalMass massDensity="1.0" />

    <BoxROI name="box" box="-1 -1 -1 11 0 11" drawBoxes="true" />
    <FixedProjectiveConstraint  name="FixedConstraint" indices="@box.indices" activate_projectVelocity="1"/>

    <TetrahedralCorotationalFEMForceField name="CFEM" youngModulus="100" poissonRatio="0.3" method="large" />
    
    <Node name="Surface">
        <TriangleSetTopologyContainer  name="Container"/>
        <TriangleSetTopologyModifier   name="Modifier" />
        <TriangleSetGeometryAlgorithms name="GeomAlgo" template="Vec3d" drawTriangles="0"/>
        <Tetra2TriangleTopologicalMapping input="@../Tetra_topo" output="@Container" />

        <TriangleCollisionModel name="triangleCol" />
        <LineCollisionModel name='edgeCol' />
        <PointCollisionModel name="pointCol" tags="CarvingSurface"/>

        <Node name="liver-Visual">
            <OglModel name="Visual" />
            <IdentityMapping input="@../../Volume" output="@Visual" />
        </Node>
    </Node>
</Node>

[epernod]

Hi,

you can take example on this scene to load a msh file: https://github.com/InfinyTech3D/SofaUnity/blob/main/Scenes/SofaScenes/liver-tetra2triangle.scn
It is the one used in the liver interaction demo

[CherryJGit]

Yes, I have changed it like this, and the test result is good. However, I want the small ball to have collision mass while not being affected by gravity. Is that possible?

<!-- 保留碰撞检测、动画循环等通用配置 -->
<VisualStyle displayFlags="hideCollisionModels showVisual" />
<DefaultVisualManagerLoop />
<DefaultAnimationLoop />
<CollisionPipeline verbose="0" />
<BruteForceBroadPhase/>
<BVHNarrowPhase/>
<CollisionResponse response="PenalityContactForceField" />
<MinProximityIntersection name="Proximity" alarmDistance="1.0" contactDistance="0.2" />

<!-- 保留求解器配置 -->
<EulerImplicitSolver name="EulerImplicit"  rayleighStiffness="0.1" rayleighMass="0.1" />
<CGLinearSolver name="CG Solver" iterations="25" tolerance="1e-9" threshold="1e-9"/>

<CarvingManager name="ACarving" active="0" carvingDistance="0.4" />

<!-- 工具节点保持不变 -->
<Node name="carvingElement">
    <MechanicalObject name="Particles" template="Vec3d" position="-1 20 -1" velocity="0 0 0"/>
    <UniformMass name="Mass" totalMass="10.0" />
    <SphereCollisionModel name="tool" radius="0.1" tags="CarvingTool"/>
</Node>

<!-- 替换Hexa2Tetra节点为网格加载器 -->
<MeshGmshLoader name="meshLoader" filename="mesh/liver2.msh" createSubelements="true" scale3d="15 15 15"/>

<Node name="Cube">
    <!-- 从加载器获取位置信息 -->
    <MechanicalObject name="Volume" position="@meshLoader.position" />

    <!-- 直接使用加载的四面体拓扑 -->
    <TetrahedronSetTopologyContainer 
        name="Tetra_topo" 
        tetrahedra="@meshLoader.tetras" 
        position="@meshLoader.position" />
    
    <TetrahedronSetTopologyModifier name="Modifier" />
    <TetrahedronSetGeometryAlgorithms 
        name="GeomAlgo" 
        template="Vec3d" 
        drawTetrahedra="0" 
        drawScaleTetrahedra="0.8"/>

    <DiagonalMass massDensity="1.0" />

    <!-- 根据实际模型调整ROI区域 -->
    <BoxROI 
        name="box" 
        box="-1 -1 -1 11 11 11"  
        drawBoxes="true" />
    <FixedProjectiveConstraint  
        name="FixedConstraint" 
        indices="@box.indices" 
        activate_projectVelocity="1"/>

    <TetrahedralCorotationalFEMForceField 
        name="CFEM" 
        youngModulus="100" 
        poissonRatio="0.3" 
        method="large" />
    
    <!-- 表面生成部分保持不变 -->
    <Node name="Surface">
        <TriangleSetTopologyContainer  name="Container"/>
        <TriangleSetTopologyModifier   name="Modifier" />
        <TriangleSetGeometryAlgorithms 
            name="GeomAlgo" 
            template="Vec3d" 
            drawTriangles="0"/>
        <Tetra2TriangleTopologicalMapping 
            input="@../Tetra_topo" 
            output="@Container" />

        <TriangleCollisionModel name="triangleCol" />
        <LineCollisionModel name='edgeCol' />
        <PointCollisionModel name="pointCol" tags="CarvingSurface"/>

        <Node name="liver-Visual">
            <OglModel name="Visual" />
            <IdentityMapping input="@../../Volume" output="@Visual" />
        </Node>
    </Node>
</Node>