[SOLVED] Change point indices when using PartialLinearMovementConstraint

[baymin]

Hi,

I am using ‘PartialLinearMovementConstraint’ to move some points on the object.
But during the simulation, when I change the indices of the points to move, the position the the new point will become (0, 0, 0).

Thank you so much for help,

baymin

[Hugo]

Hi @baymin

Would you have some scene example we could actually test?

Best

Hugo

[baymin]

Hi @Hugo,

I found that I can solve this problem by defining multi-motion in the beginning.

self.motion1 = LiverFEM.createObject('PartialLinearMovementConstraint', indices='100', keyTimes='0', template='Vec3d', movements='0 0 0')
self.motion2 = LiverFEM.createObject('PartialLinearMovementConstraint', indices='105', keyTimes='0', template='Vec3d', movements='0 0 0')

But if I just define one motion and just change the indices of motion, the second point will move from (0, 0, 0).

We use the liver demo and our animation function is as below

 def onBeginAnimationStep(self, deltaTime):
        ## Please feel free to add an example for a simple usage in /home/trs/sofa/build/unstable//home/trs/sofa/src/sofa/applications/plugins/SofaPython/scn2python.py
        cT = self.LiverFEM.getTime()
        position1 = self.LiverFEM.getObject('dofs').position[100]
        position2 = self.LiverFEM.getObject('dofs').position[105]
        position = [position1, position2]
        movements = self.LiverFEM.getObject('PartialLinearMovementConstraint').findData('movements').value
        keyTimes = self.LiverFEM.getObject('PartialLinearMovementConstraint').findData('keyTimes').value
        indices = self.LiverFEM.getObject('PartialLinearMovementConstraint').findData('indices').value

        self.control_point_index = self.control_point_index + 1
        if self.control_point_index >= 200:
            self.control_point_index = 0    
        ind = self.control_point_index // 100
        motion = [[0, 0, 0], [0, 0, 0]]
        T_dec = cT / deltaTime / 100 * 2 * 3.1415926
        motion[ind] = [0.5*math.sin(T_dec), 0.5*math.sin(T_dec), 0]
        print('ind motion', ind, motion)
        self.motion1.findData('keyTimes').value = [[cT], [cT + 100]]
        self.motion1.findData('movements').value = motion[0]
        self.motion2.findData('keyTimes').value = [[cT], [cT + 100]]
        self.motion2.findData('movements').value = motion[1]

Best

baymin

[Hugo]

Hi @baymin

thanks for sharing your solution.
Best

Hugo

[Author]

Posts