Cannot use onBeginAnimationStep function to printout the force generated by Cable_Actuator( driven by the position effector).

[Cuberkk]

Hi,

I am trying to print out the force value of 3 Cable_Actuators (driven by PositionEffector) at each time_step of the Simulation.
I tried the onBeginAnimationStep to call the data, while there is nothing coming out from the console.
I can pull out the data by using a onKeyboardEvent function in my controller. However, after implementing the PostionEffector on my scene, the onKeyboardEvent cannot work.

Anyone can give me a simple example of using onBeginAnimationStep function and give some suggestions for my problem?
main part of my Scene code:

Controller code:

[Cuberkk]

Hi,

It turns out that the onEvent function in the Sofa.Core.Controller can print out the data each iteration.