[SOLVED] Continuously Grid Topology

[Binesh]

Hi my friends
i wanna to create grid topology in animation (online)
i used regular grid topology and spatial grid container , after initialization (init function) , sofa created some grid topology , but i wanna to create same topology in run time

Thanks

Behnam Binesh

[mmabrouk]

If you’re scripting using Python, you can use the onBeginAnimationStep(self, dt) function which gets called each simulation step and create the graph objects there.

Best,
Mahmoud

[Hugo]

Exactly @mmabrouk is 100% right, consider Python.
You’ll find examples in the SofaPython plugin, documentation. In the forum, I recently gave an example about Python here.

HTH,

Hugo.

[Binesh]

Thanks Dear @Hugo and dear @mmabrouk
i read python_regulargridtopology code , i saw setPoints function in python but this function not suitable for me , i wanna topology engine for this topology , i want to change mObj and work with Force Field , so my idea is a topology engine ,
is it true ?

[Hugo]

Dear @secretdevil,

I did not forget you, I am just gathering info to answer you and give you an example scene. Cheers

Hugo

[Hugo]

Dear @secretdevil,

Please find below an example with Python (Python plugin must be compiled) to dynamically create grids.

import sys
import Sofa

class RegularGridTopology (Sofa.PythonScriptController):

    def __init__(self, node, commandLineArguments) : 
        self.commandLineArguments = commandLineArguments
        print "Command line arguments for python : "+str(commandLineArguments)
        self.createGraph(node)
        return None;

    def createGraph(self,rootNode):

        # rootNode
        self.rootNode = rootNode
        rootNode.createObject('VisualStyle', displayFlags='showBehaviorModels showForceFields showVisual')
        rootNode.createObject('CollisionPipeline', verbose='0')
        rootNode.createObject('BruteForceDetection', name='N2')
        rootNode.createObject('CollisionResponse', response='default')
        rootNode.createObject('DiscreteIntersection')

        # rootNode/LiverFFD-lowres
        LiverFFD_lowres = rootNode.createChild('LiverFFD-lowres')
        self.LiverFFD_lowres = LiverFFD_lowres
        LiverFFD_lowres.createObject('EulerImplicit', rayleighStiffness='0.1', rayleighMass='0.1')
        LiverFFD_lowres.createObject('CGLinearSolver', threshold='1e-7', tolerance='1e-7', iterations='100')
        LiverFFD_lowres.createObject('MechanicalObject')
        LiverFFD_lowres.createObject('UniformMass', totalmass='100.0')
        LiverFFD_lowres.createObject('RegularGrid', nx='4', ny='3', nz='3', xmin='-10.25', ymin='0.25', zmin='-2', xmax='-3.25', ymax='5.25', zmax='3')
        LiverFFD_lowres.createObject('BoxROI', name='myboxROI', box='-9 0 0 -4 0.9 5', drawBoxes='1') # xmin,ymin,zmin, xmax,ymax,zmax
        LiverFFD_lowres.createObject('FixedConstraint', indices='@myboxROI.indices')
        LiverFFD_lowres.createObject('RegularGridSpringForceField', name='Springs', stiffness='4000', damping='4')
        # rootNode/LiverFFD-lowres/Visu
        Visu = LiverFFD_lowres.createChild('Visu')
        self.Visu = Visu
        Visu.createObject('OglModel', color='red', translation='-5 0 0', name='Visual', fileMesh='mesh/liver-smooth.obj')
        Visu.createObject('BarycentricMapping', input='@..', output='@Visual')

        #Compute the iterations
        self.iteration_number=0

        return 0;

    def onMouseButtonLeft(self, mouseX,mouseY,isPressed):
        ## usage e.g.
        #if isPressed : 
        #    print "Control+Left mouse button pressed at position "+str(mouseX)+", "+str(mouseY)
        return 0;

    def onKeyReleased(self, c):
        ## usage e.g.
        #if c=="A" :
        #    print "You released a"
        return 0;

    def initGraph(self, node):
        ## Please feel free to add an example for a simple usage in /data/Softwares/sofa/src/master/applications/plugins/SofaPython/scn2python.py
        return 0;

    def onKeyPressed(self, c):
        ## usage e.g.
        if c=="A" :
            self.iteration_number=self.iteration_number+1
            print "iteration "+str(self.iteration_number)

            yPositionMin = 0.25+self.iteration_number*7
            yPositionMax = yPositionMin+5.25

            yPositionROIMin = self.iteration_number*7
            yPositionROIMax = yPositionROIMin+0.9

            myGrid = self.rootNode.createChild('newGrid-'+str(self.iteration_number))

            newODE = myGrid.createObject('EulerImplicit', rayleighStiffness='0.1', rayleighMass='0.1')
            newLSolver = myGrid.createObject('CGLinearSolver', threshold='1e-7', tolerance='1e-7', iterations='100')
            newMO = myGrid.createObject('MechanicalObject', showObject='1')
            newMass = myGrid.createObject('UniformMass', totalmass='100.0')
            myRegularGrid = myGrid.createObject('RegularGrid', name='myRegularGrid', nx='4', ny='3', nz='3', xmax='-3.25', xmin='-10.25', ymin=yPositionMin, ymax=yPositionMax, zmin='-2', zmax='3')

            newBox = myGrid.createObject('BoxROI', name='myboxROI', box='-9 '+str(yPositionROIMin)+' 0 -4 '+str(yPositionROIMax)+' 5', drawBoxes='1')
            newConstraint = myGrid.createObject('FixedConstraint', indices='@myboxROI.indices')
            newFF = myGrid.createObject('RegularGridSpringForceField', name='Springs', stiffness='4000', damping='4', drawMode="1")

            newODE.init()
            newLSolver.init()
            newMO.init()
            newMass.init()
            myRegularGrid.init()

            newBox.init()
            newConstraint.init()
            newFF.init()

            # rootNode/LiverFFD-lowres/Visu
            Visu = myGrid.createChild('Visu')
            self.Visu = Visu
            newOGL = Visu.createObject('OglModel', color='red', translation='-5 '+str(yPositionROIMin)+' 0', name='Visual', fileMesh='mesh/liver-smooth.obj')
            newMapping = Visu.createObject('BarycentricMapping', input='@..', output='@Visual')
            newOGL.init()
            newMapping.init()

        return 0;

def createScene(rootNode):
    rootNode.findData('dt').value = '0.01'

    rootNode.createObject('RequiredPlugin', name='SofaPython')

    try : 
        sys.argv[0]
    except :
        commandLineArguments = []
    else :
        commandLineArguments = sys.argv
    myRegularGridTopology = RegularGridTopology(rootNode,commandLineArguments)
    return 0;

You can run this script using runSofa :

runSofa your_script.py

Let me know if it helps

Hugo

[Binesh]

Thanks Dear Hugo
i try it as soon as possible

[Hugo]

hi @secretdevil,

happy new year 2018 !
did you succeed in solving your issue?
best,

Hugo

[Binesh]

Hi @Hugo
Yes, i solved my problem,
Thanks dear hugo

[Author]

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