Adding projective constraints mid-simulation

[ateixeira0163]

I would like to know if it's possible to add a constraint mid-simulation.
Let's say I have a falling rigid block and at t = 20s I would like to get the position and rotation for that block and impose a LinearMovementConstraint to it that is dependent of the position at t = 20s like :

x = node.mechanical_object.position.value[i]
node.addObject('LinearMovementConstraint`, indices=[i], relativeMovements=True, movements=[*x, x[0] + 1, ...], ...)

This, or change the movements parameter mid-simulation with a python Controller.

[fredroy]

Hello @ateixeira0163
I would not answer for all the Constraints in SOFA (because it depends on the implementation, etc) but for LinearMovementConstraint it seems the code does not do precomputing/caching/buffering so if the data are changing while simulating, it should be taken into account.
And this component is not very complex so I guess adding it into the scene in a middle of simulation should be possible IMO.

[hugtalbot]

Hi @ateixeira0163

I would go for a python3 controller which would add dynamically a LinearMovementConstraint in your node and accessing the MechanicalObject to get the current object position and define the key movements.

Have you succeeded to implement your idea?