Problem

Description I am trying to run the examples from the pneunet gripper to grab the cude from the scripts "step7-withSTLIB.py" file and "step7-grabTheCube.py".

The gripper is not able to grip the cube. If I apply more pressure the gripper is entering into the cube which should not be the case. Please find the screenshot attached.

Steps to reproduce running the script step7-grabTheCube.py and using control "+" to grip the cube.

Expected behavior The cube should be gripped and so that it can be picked up.

The code for "step7-withSTLIB.py" and "param.py" file as below.

Screenshot from 2024-10-12 18-06-10

"step7-withSTLIB.py"

`# STLIB IMPORT from stlib3.scene import MainHeader from stlib3.scene import ContactHeader from stlib3.physics.rigid import Floor, Cube from stlib3.physics.deformable import ElasticMaterialObject

SOFTROBOTS IMPORT

from softrobots.actuators import PullingCable, PneumaticCavity

CONTROLLER IMPORT

from wholeGripperController import WholeGripperController

ARGUMENTS IMPORT

from param import *

def createScene(rootNode): rootNode.addObject('RequiredPlugin', name='Sofa.Component.AnimationLoop') # Needed to use components [FreeMotionAnimationLoop] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Collision.Detection.Algorithm') # Needed to use components [BVHNarrowPhase,BruteForceBroadPhase,CollisionPipeline] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Collision.Detection.Intersection') # Needed to use components [LocalMinDistance] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Collision.Geometry') # Needed to use components [LineCollisionModel,PointCollisionModel,TriangleCollisionModel] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Collision.Response.Contact') # Needed to use components [RuleBasedContactManager] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Constraint.Lagrangian.Correction') # Needed to use components [LinearSolverConstraintCorrection,UncoupledConstraintCorrection] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Constraint.Lagrangian.Solver') # Needed to use components [GenericConstraintSolver] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Engine.Select') # Needed to use components [BoxROI]
rootNode.addObject('RequiredPlugin', name='Sofa.Component.LinearSolver.Direct') # Needed to use components [SparseLDLSolver] rootNode.addObject('RequiredPlugin', name='Sofa.Component.LinearSolver.Iterative') # Needed to use components [CGLinearSolver] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Mapping.Linear') # Needed to use components [BarycentricMapping] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Mapping.NonLinear') # Needed to use components [RigidMapping] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Mass') # Needed to use components [UniformMass]
rootNode.addObject('RequiredPlugin', name='Sofa.Component.ODESolver.Backward') # Needed to use components [EulerImplicitSolver] rootNode.addObject('RequiredPlugin', name='Sofa.Component.SolidMechanics.FEM.Elastic') # Needed to use components [TetrahedronFEMForceField] rootNode.addObject('RequiredPlugin', name='Sofa.Component.SolidMechanics.Spring') # Needed to use components [RestShapeSpringsForceField] rootNode.addObject('RequiredPlugin', name='Sofa.Component.StateContainer') # Needed to use components [MechanicalObject] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Topology.Container.Constant') # Needed to use components [MeshTopology] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Topology.Container.Dynamic') # Needed to use components [TetrahedronSetTopologyContainer,TriangleSetTopologyContainer] rootNode.addObject('RequiredPlugin', name='Sofa.Component.Visual') # Needed to use components [VisualStyle]

MainHeader(rootNode,
           plugins=['SofaPython3', 'SoftRobots'],
           gravity=[0.0, -9810, 0.0])

ContactHeader(rootNode,
              alarmDistance=5,
              contactDistance=1,
              frictionCoef=0.6)

rootNode.VisualStyle.displayFlags = "showBehaviors showCollisionModels"

Floor(rootNode, **floorParam)

cube = Cube(rootNode, **cubeParam)
cube.addObject('UncoupledConstraintCorrection')

for i in range(len(fingersParameters)):
    finger = ElasticMaterialObject(attachedTo=rootNode,
                                   volumeMeshFileName=fingersVolumeMesh,
                                   name=fingersParameters[i]['name'],
                                   rotation=fingersParameters[i]['rotation'],
                                   translation=fingersParameters[i]['translation'],
                                   surfaceMeshFileName=fingersSurfaceAndCollisionMesh,
                                   collisionMesh=fingersSurfaceAndCollisionMesh,
                                   withConstrain=True,
                                   surfaceColor=fingersColor,
                                   poissonRatio=poissonRatioFingers,
                                   youngModulus=youngModulusFingers,
                                   totalMass=fingersMass)

    finger.dofs.name = 'tetras'
    rootNode.addChild(finger)

    finger.integration.rayleighStiffness = 0.1
    finger.integration.rayleighMass = 0.1

    finger.addObject('BoxROI', name='boxROI', box=fingersParameters[i]['ROIBox'], drawBoxes=True, doUpdate=False)
    finger.addObject('RestShapeSpringsForceField', points='@../Finger1/boxROI.indices', stiffness=1e12,
                     angularStiffness=1e12)

    PneumaticCavity(surfaceMeshFileName=fingersCavitySurfaceMesh,
                    attachedAsAChildOf=finger,
                    name='Cavity',
                    rotation=fingersParameters[i]['rotation'],
                    translation=fingersParameters[i]['translation'],
                    initialValue=cavitiesInitialValue,
                    valueType='pressure')

rootNode.addObject(WholeGripperController(node=rootNode))

# -- coding: utf-8 -- import math

User parameters

cubeParam = {'name': "Cube", 'totalMass': 0.002, 'translation': [15.0, 20.0, 0.0], 'uniformScale': 21}

floorParam = {'name': "Plane", 'color': [1.0, 0.0, 1.0], 'isAStaticObject': True, 'uniformScale': 3}

Fingers Mesh & Shared Parameters

fingersVolumeMesh = 'data/mesh/pneunetCutCoarse.vtk' fingersSurfaceAndCollisionMesh = 'data/mesh/pneunetCut.stl' fingersCavitySurfaceMesh = 'data/mesh/pneunetCavityCut.stl'

Fingers Visu

fingersColor = [0.7, 0.7, 0.7, 0.6]

Fingers Position

heightInitial = 150 radius = 70 angle1 = 90 math.pi / 180 # Angle between 1st and 2nd finger in radian angle2 = 270 math.pi / 180 # Angle between 1st and 3rd finger in radian

angle3 = 360 * math.pi / 180 # Angle between 1st and 4rth finger in radian

youngModulusFingers = 500 youngModulusStiffLayerFingers = 1500 poissonRatioFingers = 0.3 fingersMass = 0.04 cavitiesInitialValue = 0.0001

Parameters for each Fingers

fingersParameters = [ { 'name': 'Finger1', 'rotation': [0.0, 0.0, -270.0], 'translation': [100.0, heightInitial, 0.0], 'ROIBox': [100, heightInitial - 10, -20, 70, heightInitial, 20], }, { 'name': 'Finger2', 'rotation': [360 - angle1 180 / math.pi, 0.0, 90.0], 'translation': [0, heightInitial, radius math.cos(angle1 - math.pi / 2)], 'ROIBox': [100, heightInitial - 10, -20, 70, heightInitial, 20], }, { 'name': 'Finger3', 'rotation': [360 - angle2 180 / math.pi, 0.0, 90.0], 'translation': [0.0, heightInitial, radius math.cos(angle2 - math.pi / 2)], 'ROIBox': [100, heightInitial - 10, -20, 70, heightInitial, 20], }
] `

Environment

Context

System: < NAME AND VERSION - e.g: "Windows 10", "Ubuntu 20.04", ... > Command: lsb_release -a Distributor ID: Ubuntu Description: Ubuntu 22.04.4 LTS Release: 22.04 Codename: jammy
Version of SOFA: v24.06.00 built with binaries
State: Build Directory
Command called


< COPY-PASTE YOUR COMMAND HERE >
![Screenshot from 2024-10-12 18-06-10](https://github.com/user-attachments/assets/47a941af-2286-435e-a832-94ccab211570)

Env vars

python -c "exec( \"import os, sys\nprint('#################')\nprint('--- sys.version ---')\nprint(sys.version)\nprint('--- PATH ---')\ntry:\n  print(os.environ['PATH'])\nexcept Exception:\n  pass\nprint('--- SOFA_ROOT ---')\ntry:\n  print(os.environ['SOFA_ROOT'])\nexcept Exception:\n  pass\nprint('--- PYTHONPATH ---')\ntry:\n  print(os.environ['PYTHONPATH'])\nexcept Exception:\n  pass\nprint('--- sys.path ---')\ntry:\n   print(str(sys.path))\nexcept Exception:\n   pass\nprint('#################')\" )"


< COPY-PASTE HERE THE RESULT OF THE COMMAND ABOVE >

Logs

Full output


< COPY-PASTE YOUR OUTPUT HERE >

Content of build_dir/CMakeCache.txt

< DRAG AND DROP YOUR CMAKECACHE.TXT HERE >

Thank you for your report.

sofa-framework / sofa

Pneunet gripper not gripping the cube #5060