How to move an object using keyboard events in Python？

[zhilengqilaiya]

Hello everyone, I created an object and then I want to make it move through keyboard events. I try to use the keyboard to update T_epm_sim to move the object in the direction that updates the object's position, but the object does not move in the scene. I don't know how to see objects moving in the scene, please help me.

The code to create the object is as follows:

import numpy as np
from scipy.spatial.transform import Rotation as R

class PermanentMagnet(Sofa.Core.Controller):
            
    def __init__(
            self,
            root_node,
            perma_magnet_stl='../mesh/epm1.stl',
            name="perma_magnet",
            T_epm_sim=[0., 0., 0., 0., 0., 0., 1.],
            color=[0.3, 0.5, 0.6, 0.8],
            *args, **kwargs):

        Sofa.Core.Controller.__init__(self, *args, **kwargs)
        self.root_node = root_node

        self.name = name
        self.perma_magnet_stl = perma_magnet_stl
        self.T_epm_sim = T_epm_sim
        self.color = color

        r = R.from_quat(self.T_epm_sim[3:7])
        rot_epm_sim = (r.as_euler('xyz', degrees=True)).tolist()

        # Collision model
        self.Colli = root_node.addChild('EPMCollisionModel')
        self.Colli.activated = True
        self.Colli.addObject(
            'MeshSTLLoader', 
            filename=self.perma_magnet_stl,
            triangulate=True,   
            name='meshLoader',
            rotation=rot_epm_sim,
            translation=self.T_epm_sim[0:3],
            scale='0.0005')
        self.Colli.addObject(
            'MeshTopology',
            position='@meshLoader.position',
            triangles='@meshLoader.triangles',
            drawTriangles='0',
            src="@meshLoader")
        self.Colli.addObject(
            'MechanicalObject',
            position=[0, 0, 0],
            scale=1,
            name='DOFs2')
        self.Colli.addObject(  
            'TriangleCollisionModel',
            moving=True,
            simulated=False)
        self.Colli.addObject(
            'LineCollisionModel',
            moving=True,
            simulated=False)
        self.Colli.addObject(
            'PointCollisionModel',
            moving=True,
            simulated=False)

        # visual model permanent magnet
        VisuModel = self.Colli.addChild(
            'VisuModel')
        VisuModel.addObject(
            'OglModel',
            name="VisualOgl_model",
            src='@../meshLoader',
            color = self.color
            )

The code to control movement is as follows:
I try to use the keyboard to update T_epm_sim to move the object in the direction that updates the object's position, but the object does not move in the scene.

DFIELD_MOVEMENT_STEP = 0.005

class ControllerSofa(Sofa.Core.Controller):

    def __init__(
            self,
            root_node,
            pmns,
            instrument,
            T_sim_mns,
            T_epm_sim=[0,0,0,0,0,0,1],  
            *args, **kwargs):

        # These are needed (and the normal way to override from a python class)
        Sofa.Core.Controller.__init__(self, *args, **kwargs)

        self.root_node = root_node
        self.pmns = pmns
        self.instrument = instrument
        self.T_sim_mns = T_sim_mns
        self.T_epm_sim = T_epm_sim

        self.permanent_magnet = mcr_perma_magnet.PermanentMagnet(
            root_node = self.root_node,
            T_epm_sim = self.T_epm_sim
        )
        self.root_node.addObject(self.permanent_magnet)

        self.mag_controller = mcr_mag_controller.MagController(
            root_node=self.root_node,
            pmns=self.pmns,
            instrument=self.instrument,
            T_sim_mns=self.T_sim_mns,
            T_epm_sim=self.T_epm_sim
            )
        self.root_node.addObject(self.mag_controller)

        self.mag_controller.T_epm_sim = self.T_epm_sim
        self.permanent_magnet.T_epm_sim = self.T_epm_sim


    def onKeypressedEvent(self, event):
        key_actions = {
            49: self.moveX,  # 1 key: x-axis movement -
            51: self.moveX,  # 3 key: x-axis movement +
            53: self.moveZ,  # 5 key: z-axis movement +
            50: self.moveZ,  # 2 key: z-axis movement -
            54: self.moveY,  # 6 key: y-axis movement +
            52: self.moveY,  # 4 key: y-axis movement -
            56: self.rotateZ,  # 8 key: z-rotation +
            57: self.rotateZ,  # 9 key: z-rotation -
            47: self.rotateX,  # / key: x-rotation +
            42: self.rotateX,  # * key: x-rotation -
            # 47: self.rotateY,  # / key: y-rotation +
            # 42: self.rotateY   # * key: y-rotation -
        }

        key = event['key']
        action = key_actions.get(ord(key))
        if action:
            action(1 if key in {'3', '5', '6', '8', '0', '/'} else -1)

    def moveX(self, val):
        # Update x-axis position
        self.T_epm_sim[0] += val * DFIELD_MOVEMENT_STEP
        # self.permanent_magnet.T_epm_sim = self.T_epm_sim
        self.mag_controller.T_epm_sim = self.T_epm_sim

    def moveZ(self, val):
        # Update z-axis position
        self.T_epm_sim[2] += val * DFIELD_MOVEMENT_STEP
        # self.permanent_magnet.T_epm_sim = self.T_epm_sim
        self.mag_controller.T_epm_sim = self.T_epm_sim

    def moveY(self, val):
        # Update y-axis position
        self.T_epm_sim[1] += val * DFIELD_MOVEMENT_STEP
        # self.permanent_magnet.T_epm_sim = self.T_epm_sim
        self.mag_controller.T_epm_sim = self.T_epm_sim

[hugtalbot]

Hi @zhilengqilaiya
Here is a script to move (translate along x) a rigid frame:

import sys
import Sofa


class MoveRigidParticles(Sofa.Core.Controller):

    def __init__(self, *args, **kwargs):
        # These are needed (and the normal way to override from a python class)
        Sofa.Core.Controller.__init__(self, *args, **kwargs)
        self.RigidBody = kwargs.get("RigidBody")

    def onKeypressedEvent(self, event):
        key = event['key']

        if key=="+" :
            with self.RigidBody.position.writeableArray() as wa:
                wa[0][0] += 0.01

        if key=="-" :
            with self.RigidBody.position.writeableArray() as wa:
                wa[0][0] -= 0.01

        return 0;



def createScene(root):
    root.gravity=[0, 0, 0]
    root.name="root"
    root.dt=0.01

    root.addObject('RequiredPlugin', name="loadSOFAModules", pluginName="Sofa.Component.LinearSolver.Iterative Sofa.Component.Mass Sofa.Component.StateContainer Sofa.Component.ODESolver.Backward")

    root.addObject('DefaultAnimationLoop', computeBoundingBox=True)
    root.bbox=[[-1,-1,-1],[1,1,1]]

    Particle = root.addChild('Particle0')
    Particle.addObject('EulerImplicitSolver')
    Particle.addObject('CGLinearSolver', threshold='1e-09', tolerance='1e-09', iterations='200')
    Particle.addObject('MechanicalObject', showObject='1', position='0 0 0    0 0 0 1', name='RigidBody', template='Rigid3d')
    Particle.addObject('UniformMass', totalMass='1')

    root.addObject( MoveRigidParticles(name="MyRigidController", RigidBody=Particle.RigidBody) )

    return 0;



def main():
    import SofaRuntime
    import Sofa.Gui
    # Make sure to load all SOFA libraries
    SofaRuntime.importPlugin("SofaBaseMechanics")
    SofaRuntime.importPlugin("SofaOpenglVisual")
    SofaRuntime.importPlugin("CImgPlugin")

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

    # Launch the GUI (qt or qglviewer)
    Sofa.Gui.GUIManager.Init("myscene", "qglviewer")
    Sofa.Gui.GUIManager.createGUI(root, __file__)
    Sofa.Gui.GUIManager.SetDimension(1080, 1080)
    # 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()

[zhilengqilaiya]

Hi! @hugtalbot 😄
Thank you very much for your example. I can move it by adding UncoupledConstraintCorrection and its required components. I’m not sure why.