Need help with diffusion

[CaroPeltier]

Hello,

I am a beginner with Sofa and I am trying to model diffusion in the headspace of a glass of solution. I attempted to base my model on the raptor example, but it doesn’t seem to work. Could you please help me?

I have attached my code below for reference.

Thank you very much for your assistance.

Best regards,

Caroline

import Sofa
from math import pi
import numpy as np
def createScene(rootNode):
    rootNode.gravity = [0, 0, 0]
    rootNode.dt = 0.1
    rootNode.addObject('BackgroundSetting', color=[0.4, 0.4, 0.4])
    # Visualisation
    rootNode.addObject("VisualStyle", displayFlags="showForceFields showVisual")
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Diffusion")
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.LinearSolver.Iterative") #<!-- Needed to use components [CGLinearSolver] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Engine.Select") #<!-- Needed to use components [BoxROI] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.IO.Mesh") #<!-- Needed to use components [MeshOBJLoader MeshVTKLoader] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Mass") #<!-- Needed to use components [MeshMatrixMass] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.ODESolver.Backward") #<!-- Needed to use components [EulerImplicitSolver] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.StateContainer") #<!-- Needed to use components [MechanicalObject] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Topology.Container.Dynamic") #<!-- Needed to use components [TetrahedronSetGeometryAlgorithms TetrahedronSetTopologyContainer TetrahedronSetTopologyModifier] -->  
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Visual") #<!-- Needed to use components [VisualStyle] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.GL.Component.Engine") #<!-- Needed to use components [TextureInterpolation] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.GL.Component.Rendering3D") #<!-- Needed to use components [OglModel] -->
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.Mapping.Linear') # Needed to use components [IdentityMapping]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.MechanicalLoad') # Needed to use components [ConstantForceField]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.Setting') # Needed to use components [BackgroundSetting]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.SolidMechanics.Spring') # Needed to use components [RestShapeSpringsForceField] 
    rootNode.addObject("VisualStyle", displayFlags="showBehaviorModels")

    # Glass
    glass = rootNode.addChild("Glass")
    glass.addObject("MeshOBJLoader", filename="./../mesh/glass.obj", name="loader", scale=1.0)
    glass.addObject("OglModel", src="@loader", color=[1, 1, 1.0, 0.05])
    
    solution = rootNode.addChild("Solution")
    solution.addObject("MeshOBJLoader", filename="./../mesh/solution.obj", name="loader", scale=1.0)
    solution.addObject("OglModel", src="@loader", color=[1, 1, 0, 0.8])

    table = rootNode.addChild("Table")
    table.addObject("MeshOBJLoader", filename="./../mesh/table.obj", name="loader", scale=1.0)
    table.addObject("OglModel", src="@loader", color=[0.2, 0.1, 0.05, 1])
    
 
    
    # Loading Air mesh
    air = rootNode.addChild("air")
    air.addObject("MeshGmshLoader", filename="./../mesh/custom_cylinder_y.msh", name="loader_air")
    air.addObject("MechanicalObject", name="air", template="Vec3", src="@loader_air" , translation=[0,1,0]) 
    air.addObject("TetrahedronSetTopologyContainer", name="topo", src="@loader_air",tags="mechanics")

    air.addObject("OglModel", name="visual", src="@loader_air", color=[0.2, 0.1, 1, 0.2])
    air.addObject("IdentityMapping", input="@air", output="@visual")
    air.addObject("EulerImplicitSolver", name="implicitSolver")
    air.addObject("CGLinearSolver", name="linearSolver", iterations=25)

    rootNode.addObject("BoxROI", name="box-hot", box="1 -1 -1 -1 1.1 1 ", drawBoxes="1", position="@air.position", tags="mechanics")
    rootNode.addObject("BoxROI", name="box-cold", box="-1 1.9 -1 1 2 1", drawBoxes="1", position="@air.position", tags="mechanics")

    # Chargement du fichier de texture thermique
    potential_loader = rootNode.addObject("MeshOBJLoader", name="potentialLoader",
        filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/cylinder_y_init.obj")

    # Animation loop
    rootNode.addObject("DefaultAnimationLoop")

    # === Noeud thermique ===
    tempNode = rootNode.addChild("Temperature")
    tempNode.gravity = [0.0, 0.0, 0.0]
    tempNode.addObject("EulerImplicitSolver", name="EulerExplicitSolver", firstOrder="1", tags="heat", rayleighStiffness=0.1, rayleighMass=0.1)
    tempNode.addObject("CGLinearSolver", name="CG", iterations=1000, tolerance=1e-10, threshold=1e-30, tags="heat")
    tempNode.addObject("MechanicalObject", template="Vec1", name="gridTemperature",
        position="@./../air/air.position", bbox="0 0 0 0 0 0", tags="heat")
    
    tempNode.addObject("TetrahedronDiffusionFEMForceField", template="Vec1", name="DiffusionForceField",
        topology="@./../air/topo", constantDiffusionCoefficient=1500, printLog="0", drawConduc="0", tagMechanics="mechanics", tags="heat")

    #    lumping="0", massDensity=1.0, printLog="0", tags="heat", topology="@../air/topo", geometryState="@../airMechanicalObject")

    # Contraintes d’amorçage thermique via ROI
    tempNode.addObject("LinearMovementProjectiveConstraint", template="Vec1",
        keyTimes="0 0.005 0.006", movements="0 0 1", indices="@../box-cold.indices")
    tempNode.addObject("LinearMovementProjectiveConstraint", template="Vec1",
       keyTimes="0.001 0.002 0.004 0.005 0.006", movements="0 1 0.5 1 0", indices="@../box-hot.indices")

    # === Visualisation thermique ===
    
    visu = tempNode.addChild("Visu")
    visu.addObject("TextureInterpolation", template="Vec1", name="EngineInterpolation",
        input_states="@../tempNode/gridTemperature.position", input_coordinates="@../../air/air.position",
        min_value=0.0, max_value=1.0, manual_scale="1", drawPotentiels="0", showIndicesScale="5e-05")
    ogl_model = visu.addObject("OglModel", template="Vec3", name="oglPotentiel",
        texcoords="@EngineInterpolation.output_coordinates", handleDynamicTopology="0",
        texturename="C:/Users/capeltier/Desktop/SOFA_v24.12.00_Win64/share/sofa/textures/heatColor.bmp",
        scale3d="1 1 1",
        material="Default Diffuse 1 1 1 1 0.5 Ambient 1 1 1 1 0.3 Specular 0 0.5 0.5 0.5 1 Emissive 0 0.5 0.5 0.5 1 Shininess 0 45")
    visu.addObject("IdentityMapping", input="@../../airMechanicalObject", output="@oglPotentiel")
    return rootNode

L'erreur obtenue est :

# [ERROR]   [TetrahedronDiffusionFEMForceField(DiffusionForceField)] cannot find the mechanical object named '0000000000000000

[hugtalbot]

Hi @CaroPeltier

Indeed the diffusion scenes are quite special in their construction.
Here the error is due to the fact that the TetrahedronDiffusionFEMForceField component is looking for a MechanicalObject in the above node with tag="mechanics"

You should therefore update :

...
    air.addObject("MechanicalObject", name="air", template="Vec3", src="@loader_air" , translation=[0,1,0], tags="mechanics") 
...

[CaroPeltier]

Hi,

I’ve added the tag "mechanics" to my air object, but I’m still getting the same error message.
Do you have any idea what might be causing this?

To try and fix the issue, I also attempted to move my mechanical object to the root.node, instead of placing it inside a child node (as done in the Raptor example). However, in that case, the translation doesn’t seem to work properly, so I gave up on that approach.

Thank you very much for your help!

Caroline

[bakpaul]

Hello, the tempNode needs to be a child of the air node. Here they are unrealated. Could you make this change :
tempNode = rootNode.addChild("Temperature") --> tempNode = air.addChild("Temperature")

And of course you'll have to change all of the paths to point correctly to the air node.

[github-actions[bot]]

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@CaroPeltier
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

[CaroPeltier]

Hi,
I did not succeed in running my scene without errors. My last attempt was as follows:
Thank you very much for your help,
All the best,
Caroline

import Sofa
from math import pi
import numpy as np
def createScene(rootNode):
    rootNode.gravity = [0, 0, 0]
    rootNode.dt = 0.1
    rootNode.addObject('BackgroundSetting', color=[0.4, 0.4, 0.4])
    # Visualisation
    rootNode.addObject("VisualStyle", displayFlags="showForceFields showVisual")
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Diffusion")
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.LinearSolver.Iterative") #<!-- Needed to use components [CGLinearSolver] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Engine.Select") #<!-- Needed to use components [BoxROI] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.IO.Mesh") #<!-- Needed to use components [MeshOBJLoader MeshVTKLoader] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Mass") #<!-- Needed to use components [MeshMatrixMass] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.ODESolver.Backward") #<!-- Needed to use components [EulerImplicitSolver] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.StateContainer") #<!-- Needed to use components [MechanicalObject] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Topology.Container.Dynamic") #<!-- Needed to use components [TetrahedronSetGeometryAlgorithms TetrahedronSetTopologyContainer TetrahedronSetTopologyModifier] -->  
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Visual") #<!-- Needed to use components [VisualStyle] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.GL.Component.Engine") #<!-- Needed to use components [TextureInterpolation] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.GL.Component.Rendering3D") #<!-- Needed to use components [OglModel] -->
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.Mapping.Linear') # Needed to use components [IdentityMapping]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.MechanicalLoad') # Needed to use components [ConstantForceField]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.Setting') # Needed to use components [BackgroundSetting]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.SolidMechanics.Spring') # Needed to use components [RestShapeSpringsForceField] 
    rootNode.addObject("VisualStyle", displayFlags="showBehaviorModels")

    # Glass
    glass = rootNode.addChild("Glass")
    glass.addObject("MeshOBJLoader", filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/sofaTests/mesh/glass.obj", name="loader", scale=1.0)
    glass.addObject("OglModel", src="@loader", color=[1, 1, 1.0, 0.05])
    
    solution = rootNode.addChild("Solution")
    solution.addObject("MeshOBJLoader", filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/mesh/solution.obj", name="loader", scale=1.0)
    solution.addObject("OglModel", src="@loader", color=[1, 1, 0, 0.8])

    table = rootNode.addChild("Table")
    table.addObject("MeshOBJLoader", filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/mesh/table.obj", name="loader", scale=1.0)
    table.addObject("OglModel", src="@loader", color=[0.2, 0.1, 0.05, 1])
        
    # Loading Air mesh
    air = rootNode.addChild("air")
    air.addObject("MeshGmshLoader", filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/mesh/custom_cylinder_y.msh", name="loader_air")
    air.addObject("MechanicalObject", name="air", template="Vec3", src="@loader_air" , translation=[0,1,0]) 
    air.addObject("TetrahedronSetTopologyContainer", name="topo", src="@loader_air",tags="mechanics")

    air.addObject("OglModel", name="visual", src="@loader_air", color=[0.2, 0.1, 1, 0.2])
    air.addObject("IdentityMapping", input="@air", output="@visual")
    air.addObject("EulerImplicitSolver", name="implicitSolver")
    air.addObject("CGLinearSolver", name="linearSolver", iterations=25)

    rootNode.addObject("BoxROI", name="box-hot", box="1 -1 -1 -1 1.1 1 ", drawBoxes="1", position="@air.position", tags="mechanics")
    rootNode.addObject("BoxROI", name="box-cold", box="-1 1.9 -1 1 2 1", drawBoxes="1", position="@air.position", tags="mechanics")

    # Chargement du fichier de texture thermique
    potential_loader = rootNode.addObject("MeshOBJLoader", name="potentialLoader",
        filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/cylinder_y_init.obj")

    # Animation loop
    rootNode.addObject("DefaultAnimationLoop")

    # === Noeud thermique ===
    tempNode = rootNode.addChild("Temperature")
    tempNode.gravity = [0.0, 0.0, 0.0]
    tempNode.addObject("EulerImplicitSolver", name="EulerExplicitSolver", firstOrder="1", tags="heat", rayleighStiffness=0.1, rayleighMass=0.1)
    tempNode.addObject("CGLinearSolver", name="CG", iterations=1000, tolerance=1e-10, threshold=1e-30, tags="heat")
    tempNode.addObject("MechanicalObject", template="Vec1", name="gridTemperature",
        position="@./../air/air.position", bbox="0 0 0 0 0 0", tags="heat")
    
    tempNode.addObject("TetrahedronDiffusionFEMForceField", template="Vec1", name="DiffusionForceField",
        topology="@./../air/topo", constantDiffusionCoefficient=1500, printLog="0", drawConduc="0", tagMechanics="mechanics", tags="heat")

    #    lumping="0", massDensity=1.0, printLog="0", tags="heat", topology="@../air/topo", geometryState="@../airMechanicalObject")

    # Contraintes d’amorçage thermique via ROI
    tempNode.addObject("LinearMovementProjectiveConstraint", template="Vec1",
        keyTimes="0 0.005 0.006", movements="0 0 1", indices="@../box-cold.indices")
    tempNode.addObject("LinearMovementProjectiveConstraint", template="Vec1",
       keyTimes="0.001 0.002 0.004 0.005 0.006", movements="0 1 0.5 1 0", indices="@../box-hot.indices")

    # === Visualisation thermique === 
    visu = tempNode.addChild("Visu")
    visu.addObject("TextureInterpolation", template="Vec1", name="EngineInterpolation",
        input_states="@../tempNode/gridTemperature.position", input_coordinates="@../../air/air.position",
        min_value=0.0, max_value=1.0, manual_scale="1", drawPotentiels="0", showIndicesScale="5e-05")
    ogl_model = visu.addObject("OglModel", template="Vec3", name="oglPotentiel",
        texcoords="@EngineInterpolation.output_coordinates", handleDynamicTopology="0",
        texturename="C:/Users/capeltier/Desktop/SOFA_v24.12.00_Win64/share/sofa/textures/heatColor.bmp",
        scale3d="1 1 1",
        material="Default Diffuse 1 1 1 1 0.5 Ambient 1 1 1 1 0.3 Specular 0 0.5 0.5 0.5 1 Emissive 0 0.5 0.5 0.5 1 Shininess 0 45")
    visu.addObject("IdentityMapping", input="@../../airMechanicalObject", output="@oglPotentiel")
    return rootNode

[WARNING] [BoxROI(box-hot)] No rest position yet defined. ROI might not work properly.
This may be caused by an early initialization of the ROI before
the mesh or the MechanicalObject of the node was initialized too
[WARNING] [BoxROI(box-cold)] No rest position yet defined. ROI might not work properly.
This may be caused by an early initialization of the ROI before
the mesh or the MechanicalObject of the node was initialized too
[WARNING] [CGLinearSolver(linearSolver)] Required data "tolerance" has not been set. Falling back to default value: 1e-05
[WARNING] [CGLinearSolver(linearSolver)] Required data "threshold" has not been set. Falling back to default value: 1e-05
[ERROR] [TetrahedronDiffusionFEMForceField(DiffusionForceField)] cannot find the mechanical object named '0000000000000000

[WARNING] [OglModel(oglPotentiel)] Neither an .obj file nor a topology is present for this VisualModel.

[bakpaul]

Hello your last attempt didn't take my suggestion into account.

Hello, the tempNode needs to be a child of the air node. Here they are unrealated. Could you make this change :
tempNode = rootNode.addChild("Temperature") --> tempNode = air.addChild("Temperature")

And of course you'll have to change all of the paths to point correctly to the air node.

[CaroPeltier]

Oops, sorry about that — thank you! Here is an updated version (though I'm not sure if my paths correctly point to the air node). The error message is:
[ERROR] [TetrahedronDiffusionFEMForceField(DiffusionForceField)] cannot find the mechanical object named '0000000000000000'"

import Sofa
from math import pi
import numpy as np
def createScene(rootNode):
    rootNode.gravity = [0, 0, 0]
    rootNode.dt = 0.1
     # Visualisation

    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Diffusion")
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.LinearSolver.Iterative") #<!-- Needed to use components [CGLinearSolver] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Engine.Select") #<!-- Needed to use components [BoxROI] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.IO.Mesh") #<!-- Needed to use components [MeshOBJLoader MeshVTKLoader] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Mass") #<!-- Needed to use components [MeshMatrixMass] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.ODESolver.Backward") #<!-- Needed to use components [EulerImplicitSolver] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.StateContainer") #<!-- Needed to use components [MechanicalObject] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Topology.Container.Dynamic") #<!-- Needed to use components [TetrahedronSetGeometryAlgorithms TetrahedronSetTopologyContainer TetrahedronSetTopologyModifier] -->  
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.Component.Visual") #<!-- Needed to use components [VisualStyle] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.GL.Component.Engine") #<!-- Needed to use components [TextureInterpolation] -->
    rootNode.addObject("RequiredPlugin", pluginName="Sofa.GL.Component.Rendering3D") #<!-- Needed to use components [OglModel] -->
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.Mapping.Linear') # Needed to use components [IdentityMapping]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.MechanicalLoad') # Needed to use components [ConstantForceField]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.Setting') # Needed to use components [BackgroundSetting]
    rootNode.addObject('RequiredPlugin', name='Sofa.Component.SolidMechanics.Spring') # Needed to use components [RestShapeSpringsForceField] 
    rootNode.addObject("VisualStyle", displayFlags="showBehaviorModels")
    rootNode.addObject("VisualStyle", displayFlags="showForceFields showVisual")
    # Glass
    glass = rootNode.addChild("Glass")
    glass.addObject("MeshOBJLoader", filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/mesh/glass.obj", name="loader", scale=1.0)
    glass.addObject("OglModel", src="@loader", color=[1, 1, 1.0, 0.05])
    
    solution = rootNode.addChild("Solution")
    solution.addObject("MeshOBJLoader", filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/mesh/solution.obj", name="loader", scale=1.0)
    solution.addObject("OglModel", src="@loader", color=[1, 1, 0, 0.8])

    table = rootNode.addChild("Table")
    table.addObject("MeshOBJLoader", filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/mesh/table.obj", name="loader", scale=1.0)
    table.addObject("OglModel", src="@loader", color=[0.2, 0.1, 0.05, 1])
    
    # Loading Air mesh
    air = rootNode.addChild("air")
    air.addObject("MeshGmshLoader", filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/mesh/custom_cylinder_y.msh", name="loader_air")
    air.addObject("MechanicalObject", name="air", template="Vec3", src="@loader_air" , translation=[0,1,0]) 
    air.addObject("TetrahedronSetTopologyContainer", name="topo", src="@loader_air",tags="mechanics")

    air.addObject("OglModel", name="visual", src="@loader_air", color=[0.2, 0.1, 1, 0.2])
    air.addObject("IdentityMapping", input="@air", output="@visual")
    air.addObject("EulerImplicitSolver", name="implicitSolver")
    air.addObject("CGLinearSolver", name="linearSolver", iterations=25)

    rootNode.addObject("BoxROI", name="box-hot", box="1 -1 -1 -1 1.1 1 ", drawBoxes="1", position="@air.position", tags="mechanics")
    rootNode.addObject("BoxROI", name="box-cold", box="-1 1.9 -1 1 2 1", drawBoxes="1", position="@air.position", tags="mechanics")

    # Chargement du fichier de texture thermique
    potential_loader = rootNode.addObject("MeshOBJLoader", name="potentialLoader",
        filename="C:/Users/capeltier/Nextcloud/MyDrive/ProjetsEnCours/2023_Digimouth/digimouth_work/digimouth_pkg/cylinder_y_init.obj")

    # Animation loop
    rootNode.addObject("DefaultAnimationLoop")

    # === Noeud thermique ===
    tempNode = air.addChild("Temperature")
    tempNode.gravity = [0.0, 0.0, 0.0]
    tempNode.addObject("EulerImplicitSolver", name="EulerExplicitSolver", firstOrder="1", tags="heat", rayleighStiffness=0.1, rayleighMass=0.1)
    tempNode.addObject("CGLinearSolver", name="CG", iterations=1000, tolerance=1e-10, threshold=1e-30, tags="heat")
    tempNode.addObject("MechanicalObject", template="Vec1", name="gridTemperature",
       position="@../../air.position", bbox="0 0 0 0 0 0", tags="heat")
    tempNode.addObject("TetrahedronDiffusionFEMForceField", template="Vec1", name="DiffusionForceField",
        topology="@../../air/topo", constantDiffusionCoefficient=1500, printLog="0", drawConduc="0", tagMechanics="mechanics", tags="heat")

    #    lumping="0", massDensity=1.0, printLog="0", tags="heat", topology="@../air/topo", geometryState="@../airMechanicalObject")
    # Contraintes d’amorçage thermique via ROI
    tempNode.addObject("LinearMovementProjectiveConstraint", template="Vec1",
        keyTimes="0 0.005 0.006", movements="0 0 1", indices="@../box-cold.indices")
    tempNode.addObject("LinearMovementProjectiveConstraint", template="Vec1",
       keyTimes="0.001 0.002 0.004 0.005 0.006", movements="0 1 0.5 1 0", indices="@../box-hot.indices")

    # === Visualisation thermique === 
    visu = tempNode.addChild("Visu")
    visu.addObject("TextureInterpolation", template="Vec1", name="EngineInterpolation",
        input_states="@../tempNode/gridTemperature.position", input_coordinates="@../../air/air.position",
        min_value=0.0, max_value=1.0, manual_scale="1", drawPotentiels="0", showIndicesScale="5e-05")
    ogl_model = visu.addObject("OglModel", template="Vec3", name="oglPotentiel",
        texcoords="@EngineInterpolation.output_coordinates", handleDynamicTopology="0",
        texturename="C:/Users/capeltier/Desktop/SOFA_v24.12.00_Win64/share/sofa/textures/heatColor.bmp",
        scale3d="1 1 1",
        material="Default Diffuse 1 1 1 1 0.5 Ambient 1 1 1 1 0.3 Specular 0 0.5 0.5 0.5 1 Emissive 0 0.5 0.5 0.5 1 Shininess 0 45")
    visu.addObject("IdentityMapping", input="@../../airMechanicalObject", output="@oglPotentiel")
    return rootNode



def main():
    import SofaRuntime
    import Sofa.Gui

    # Create the root node
    root = Sofa.Core.Node("root")
    # Call the below 'createScene' function to create the scene graph
    createScene(root)
    # Initialize the graph from the root node
    Sofa.Simulation.initRoot(root)

    # Launch the GUI (qt or qglviewer)
    Sofa.Gui.GUIManager.Init("myscene", "qglviewer")
    Sofa.Gui.GUIManager.createGUI(root, __file__)
    Sofa.Gui.GUIManager.SetDimension(1080, 800)
    # Initialization of the scene will be done here
    Sofa.Gui.GUIManager.MainLoop(root)
    Sofa.Gui.GUIManager.closeGUI()

    print("Simulation is done.")



# Function used only if this script is called from a python environment
if __name__ == '__main__':
    main()

It seems that the python command is not working with this file :
[ERROR] [SofaRuntime] ValueError: Object type LinearMovementProjectiveConstraint was not created
The component 'LinearMovementProjectiveConstraint' cannot be found in the factory.
Thank you again,
Caroline

[bakpaul]

Hello !

I wasn't able to launch your simulation given that I don't have the meshes. But looking at your error message, I took a look at the source code and I think that I understand the problem. The component is looking above him for a MechanicalObject with a tag that is equal to your mechaTag. So to fix this you should add tag="mechanics".

And also I saw an unusual placement of the Animation loop. I would suggest to put it right after the required plugin components, and before any component that is simulation related.

[CaroPeltier]

Hello !
Thank you very much, I have no error anymore.
Thank you again for your help.
Caroline