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Hey @Hugo,
No I don’t have access to it. Can you give it to me or should I ask M.Duriez for it ?
Best
BenjaminHey Hugo,
Okay, I am using a lot the BeamAdapter plugin with its different options.
Yes, I agree with you that it could be interesting to implement it. I can try to implement it if you want.
I am using the binary version of BeamAdapter (a precompiled version of SOFA 19.06.99 that you gave me during a GDR day on soft robots in winter 2019).Best,
Benjamin
Hi @Hugo,
Thank you for your answer. Understandably, you take time to answer due to the number of people asking for your help.
That’s true that my SOFA version starts being old. You gave me that version (containing the soft robot plugin and the inverse plugin) on a GDR day. If I want to update it, I don’t know if it will be easy to get the same plugins.
– For the AttachConstraint and the BilaterallC, I’m using the same data fields (two objects (beams) with only one index).
– If I commented on the BilaterallC, there is no error, just a warning about the denominator threshold of GC that is reached at the first iteration.Sorry for the link to GitHub. So here is the code that I’m using.
import Sofa from splib.constants import Key # mm and kg units # BEAM_LENGTH = 100 # in mm # BEAM_RADIUS = 0.5 # in mm # BEAM_DENSITY = 6.45e-6 # in kg/mm^3 # YOUNG_MODULUS = 160e6 # 160 GPa = 160e9 Pa = 160e9 N/(m.s^2) = 160e6 N/(mm.s^2) # ELEMENT_NUMBER = 10 # GRAVITATIONAL_ACCELERATION = 9806.65 # in mm/s^2 # STEP_TIME = 0.001 # in s # LOAD_MASS = 0.5 # in kg # SI Units BEAM_LENGTH = 0.1 # in m BEAM_RADIUS = 0.5e-3 # in m BEAM_DENSITY = 6450 # in kg/m^3 YOUNG_MODULUS = 160e9 # in Pa ELEMENT_COUNT = 5 GRAVITATIONAL_ACCELERATION = 9.80665 # in m/s^2 STEP_TIME = 0.01 # in s LOAD_MASS = 0.1 # in kg # OpenGL SLICE_COUNT = 100 SECTOR_COUNT = 5 def createScene(rootNode): print('---------- Entering createScene ----------') rootNode.createObject('RequiredPlugin',pluginName='SoftRobots BeamAdapter SofaPython SofaSparseSolver') rootNode.createObject('VisualStyle', displayFlags='showVisualModels showBehaviorModels showCollisionModels hideBoundingCollisionModels showForceFields showInteractionForceFields hideWireframe') rootNode.createObject('BackgroundSetting', color=[0.0, 0.0, 0.0, 1.0]) rootNode.dt = STEP_TIME rootNode.gravity = [0.0, -GRAVITATIONAL_ACCELERATION, 0.0] rootNode.createObject('GenericConstraintSolver', name="genericConstraintSolver1", maxIterations="10000", tolerance="1e-12") rootNode.createObject('FreeMotionAnimationLoop') # rootNode.createObject('DefaultPipeline', verbose="0") # rootNode.createObject('BruteForceDetection', name="N2") # rootNode.createObject('DefaultContactManager', response="FrictionContact", responseParams="mu=0.6") # rootNode.createObject('LocalMinDistance', name="Proximity", alarmDistance="0.05", contactDistance="0.001", angleCone="0.00") rootNode.createObject('OglSceneFrame', style="Arrows", alignment="TopRight") # rootNode.createObject('DefaultPipeline', verbose="0") # rootNode.createObject('BruteForceDetection', name="N2") # rootNode.createObject('DefaultPipeline', verbose="0") rootNode.createObject('PythonScriptController', classname="Controller") ##### Compute the beam topology using python edgesList = [] for i in range(0, ELEMENT_COUNT): edgesList.append([i, i + 1]) print("edgesList = ", edgesList) positionsList = [] for i in range(0, ELEMENT_COUNT + 1): dx = BEAM_LENGTH / ELEMENT_COUNT positionsList.append([dx * i, 0.0, 0.0, 0.0, 0.0, 0.0, 1]) print("positionsList = ", positionsList) wall = rootNode.createChild('wall') wall.createObject('EulerImplicitSolver', name="odesolverwall", rayleighStiffness="0.1", rayleighMass="0.1") # wall.createObject('SparseLDLSolver') wall.createObject('CGLinearSolver', iterations="100", tolerance="1.0e-9", threshold="1.0e-9" ) # wall.createObject('BTDLinearSolver', printLog="false", verbose="false") wall.createObject('MechanicalObject', name='wallFrame', template="Rigid3", position=['0.0 -0.05 0.0 0.0 0.0 0.707 0.707','0.0 0.0 0.0 0.0 0.0 0.707 0.707','0.0 0.05 0.0 0.0 0.0 0.707 0.707']) wall.createObject('MeshTopology', edges=['0 1','1 2']) # beam.createObject('BeamInterpolation', name='interpolation', crossSectionShape='rectangular', lengthY=2*BEAM_RADIUS, lengthZ=2*BEAM_RADIUS, defaultYoungModulus=YOUNG_MODULUS) wall.createObject('BeamInterpolation', name='wallinter', crossSectionShape='circular', radius=BEAM_RADIUS, innerRadius=0.0, defaultYoungModulus=YOUNG_MODULUS, dofsAndBeamsAligned=1) wall.createObject('AdaptiveBeamForceFieldAndMass', name='wallForceField', computeMass=1, massDensity=BEAM_DENSITY) wall.createObject('PartialFixedConstraint', name='clampingProxEnd', indices=['0','1','2'], fixedDirections='0 1 1 1 1 1') wall.createObject('UniformMass', totalMass="0.1", showAxisSizeFactor="0.01") # wall.createObject('LinearSolverConstraintCorrection') wall.createObject('UncoupledConstraintCorrection') ##### Beam model beam = rootNode.createChild('beam') beam.createObject('EulerImplicitSolver', name="odesolverbeam", rayleighStiffness="0.1", rayleighMass="0.1") beam.createObject('CGLinearSolver', iterations="100", tolerance="1.0e-9", threshold="1.0e-9" ) # beam.createObject('SparseLDLSolver') # beam.createObject('BTDLinearSolver', printLog="false", verbose="false") beam.createObject('MechanicalObject', name='frame', template="Rigid3", position=positionsList) beam.createObject('MeshTopology', edges=edgesList) # beam.createObject('BeamInterpolation', name='interpolation', crossSectionShape='rectangular', lengthY=2*BEAM_RADIUS, lengthZ=2*BEAM_RADIUS, defaultYoungModulus=YOUNG_MODULUS) beam.createObject('BeamInterpolation', name='interpolation', crossSectionShape='circular', radius=BEAM_RADIUS, innerRadius=0.0, defaultYoungModulus=YOUNG_MODULUS, DOF0TransformNode0=['0.0 0.0 0.0 0.0 0.0 0.0 0.0','0.0 0.0 0.0 0.0 0.0 0.0 0.0','0.0 0.0 0.0 0.0 0.0 0.0 0.0'], DOF1TransformNode1=['0.0 0.0 0.0 0.0 0.0 0.0 0.0','0.0 0.0 0.0 0.0 0.0 0.0 0.0','0.0 0.0 0.0 0.0 0.0 0.0 0.0'], dofsAndBeamsAligned=1.0) beam.createObject('AdaptiveBeamForceFieldAndMass', name='BeamForceField', computeMass=1, massDensity=BEAM_DENSITY) beam.createObject('UniformMass', totalMass="0.1", showAxisSizeFactor="0.01" ) # beam.createObject('LinearSolverConstraintCorrection') beam.createObject('UncoupledConstraintCorrection') ##### Clamping # beam.createObject('FixedConstraint', name='clamping', indices='0') beam.createObject('PartialFixedConstraint', name='clampingProxEnd', indices='0', fixedDirections='0 1 1 1 1 1') beam.createObject('FixedConstraint', name='clampingDisEnd', indices=ELEMENT_COUNT) # rootNode.createObject('AttachConstraint', name='constforPal', object1="@wall", object2="@beam", indices1="0", indices2="0", constraintFactor="1",twoWays='1') # rootNode.createObject('BilateralInteractionConstraint', template="Rigid3", object1="@wall", object2="@beam", first_point="1", second_point="0") print('---------- Exiting createScene ----------') return rootNode class Controller(Sofa.PythonScriptController): def createGraph(self, node): print('---------- Entering createGraph ----------') self.node = node print('---------- Exiting createGraph ----------') def reset(self): print('---------- Entering reset ----------') self.time = 0.0 print('---------- Exiting reset ----------') return 0 def onBeginAnimationStep(self, dt): return 0 def onEndAnimationStep(self, dt): return 0 def onKeyPressed(self, key): print("Key Pressed") if key == Key.U: # mouvements suivant l'axe X self.node.wall.wallFrame.rest_position=self.node.wall.wallFrame.position return 0Hello everyone,
Maybe my post was not as clear as I thought so I created something easier. I created 2 beams. What I want is to connect the first indices of both beams.
I tried two things:
– I tried to use
AttachConstraintbut it did not work. The two beams were linked but when I moved one the other one did not follow even if there was the link between them.
I tried to take some inspiration fromI tried to update the position and rest position of the beam but it did not work.
– I also tried to use BilateralInteractionConstraint as propose in the following post:
But error saying that the determinant of a matrix is too small but I do not see how I can solve that
You can find the BeamMultiCompMoving.py file where both options are implemented at the following link.
Can you help me on this connection between two points of different objects, please ?
Cheers,
BenjaminHi @alexbilger,
I am very interesting by the different components of your two previous answers. If I want to use them, do I have to build the last version of SOFA or is it possible do get it with my current SOFA v19.06. version.
Cheers,
BenjaminI solved the problem. To move the mecanical object, all the involved positions need to be specified and not only one.
Hi @jnbrunet,
Thank you so much for your answer! It is working well now. My apologies for asking for your help. I should have looked at the .h file of SpringStiffness to find the solution..
Benjamin
Hi @Hugo,
Thank you for your response.
The class SlidingActuator, using a Ridif3d template, has a direction component but all the values inside need to be 0 or 1 (0.7017 working sometimes).
Using a Vect3d template, it seems that the direction can only take three parameters (not limited to 0 or 1).
So I tried to use the Vect3d template but I get another problem. Sofa tell me that this node (indice 1 in my MecaModelNode) did not have any mechanical state associated.
The given advise is to create another mechanical object. Is this object could be used as a boundary condition for the beam interpolation or linked to the current point ?I have another question about what you mean by sliding contraint in your response. Do you mean that inside the sliding actuator there is already a sliding constraint or must I remplace the partialFixedConstraint by a SlidingConstraint ?
Kind Regards,
BenjaminHi @hugo,
My apologies for the late answer. It is exactly the case yes. However, the axis need to be orientated in the space.
I took a look at the sliding constraint example. However, I did not succeed to constraint the point of my solid to the line, as in the example. I tried to understand why.
The sliding constraint take in parameters two Vec3d. I created one object from the <i>rootNode</i> (the line) and another from my <i>MechanicalModelNode</i> (the sliding point). It seemed that the field <i>UncoupledConstraintCorrection</i> is essential for the sliding constraint but I did not succeed to use it. The <i>UncoupledConstraintCorrection</i> is link to the mass of the object but the mass compute by the <i> AdaptiveBeamForceFieldAndMass </i> is not recognised as such.The actuator is supposed to push or pull a object in a straight line. The orientation of this line is not colinear to the world frame axis.
Kind regards,
Benjamin
