[SOLVED] SofaPython3 getObjects

[Eric]

Hi All,

I’ve started creating my surgical scene by imitating liver.py, and now I’m wondering if there is any documentation available that records sofaPython3 functions.

For example, I am trying to add fixed constraints to my tissue meshes nodes whose x coordinate is smaller than 0.01, which requires me to retrieve mesh nodes positions. However, I don’t know which function is responsible for “getobject” and “getPosX” in python. Could you help with it?

Cheers

[Hugo]

hey @ericcui

Definitely, please find the readthedoc for SofaPython3!

I advice you to take a look this example which gives a good example of a so-called “python controller” : a python class that allows to define actions while the simulation is running.

However, in your case, all you need to do is to define a BoxROI with a FixedConstraint more or less as follows:

node.addObject('BoxROI', name="BoxSelectingPointToBeFixed", box="-999 -999 -999 0.01 999 999" )
node.addObject('FixedConstraint', name="FixedConstraint", indices="@BoxSelectingPointToBeFixed.indices", listening="true")

Best wishes,

Hugo

[Eric]

Hi Hugo,

Thanks for your reply and suggestion.

I’ve followed the example of “python controller” as https://github.com/sofa-framework/SofaPython3/blob/master/examples/liver-scriptcontroller.py, but still fail to stream position data when I trigger the event.

My code is attached as below, aiming to print out the position of the first tissue index on pressing “ctrl + “+””
In the createScene(root) function, I create the scene with root and tissue node

tissue = root.addChild('tissue')
tissue.addObject('MechanicalObject', name = tissueDofs, src=@tissueMeshLoader)
root.addObject( KeyPressedController(name=tissueController )

In the trigger function, I define

class KeyPressedController(Sofa.Core.Controller):
    def __init__(self, *args, **kwargs):
        Sofa.Core.Controller.__init__(self, *args, **kwargs)
        self.iteration = 0

    def onKeypressEvent(self, event):
        if event['key']== "+":
            root_now = self.getContext()
            tissue_now = root_now.tissue.tissueDofs
            with tissue_now.position.writeableArray() as wa:
                print(wa[0])

However, after I start the simulation and press “ctrl + “+””, I only received [INFO] [SofaViewer] QtViewer::keyPressEvent, CONTROL pressed but no position data was printed out. Could you help point out what might be the reason?

In addition, is there other way to trigger an event than pressing a key? For example, in a tissue cutting simulation in which only when the distance between scalpel and tissue surface is closer enough could a Topology modification event be triggered.

Cheers

[Eric]

Hi Hugo,

Thanks for your reply and suggestion.

I’ve followed the example of “python controller” as https://github.com/sofa-framework/SofaPython3/blob/master/examples/liver-scriptcontroller.py, but still fail to stream position data when I trigger the event.

My code is attached as below, aiming to print out the position of the first tissue index on pressing “ctrl + “+””
In the createScene(root) function, I create the scene with root and tissue node

tissue = root.addChild('tissue')
tissue.addObject('MechanicalObject', name = "tissueDofs", src="@tissueMeshLoader")
root.addObject( KeyPressedController(name="tissueController") )

In the trigger function, I define

class KeyPressedController(Sofa.Core.Controller):
    def __init__(self, *args, **kwargs):
        Sofa.Core.Controller.__init__(self, *args, **kwargs)
        self.iteration = 0

    def onKeypressEvent(self, event):
        if event['key']=="+":
            root_now = self.getContext()
            tissue_now = root_now.tissue.tissueDofs
            with tissue_now.position.writeableArray() as wa:
                print(wa[0])

However, after I start the simulation and press “ctrl + “+””, I only received [INFO] [SofaViewer] QtViewer::keyPressEvent, CONTROL pressed but no position data was printed out. Could you help point out what might be the reason?

In addition, is there other way to trigger an event than pressing a key? For example, in a tissue cutting simulation in which only when the distance between scalpel and tissue surface is closer enough could a Topology modification event be triggered.

Cheers

[Hugo]

Hi @ericcui

I close this topic since the question got a reply there: https://www.sofa-framework.org/community/forum/topic/access-object-data-on-the-fly-sofapython3/

Best

Hugo

[Author]

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