Pickling of "pinocchio.pinocchio_pywrap_casadi.Model" instances is not enabled

[TexnoMann]

Bug description

Python bindings for the casadi model cannot be serialized via pickle.

Expected behavior

pinocchio.casadi.Model must also be serializable

Reproduction steps

Install pinocchio==3.2.0 from conda-forge channel and run provided bellow code

Code

import unittest
import sys
import os
import pickle

import pinocchio as pin
from pinocchio import casadi as cpin

import casadi
from casadi import SX
import numpy as np


class TestMainAlgos(unittest.TestCase):
    def setUp(self):
        self.model = pin.buildSampleModelHumanoidRandom()
        self.data = self.model.createData()

        self.cmodel = cpin.Model(self.model)
        self.cdata = self.cmodel.createData()

    def test_pickle(self):
        cmodel = self.cmodel
        cdata = self.cdata
        with open("cmodel.pkl", "wb") as f:
            pickle.dump(cmodel, f)
        with open("cdata.pkl", "wb") as f:
            pickle.dump(cdata, f)


if __name__ == "__main__":
    unittest.main()

System

• OS: Ubuntu 20.04
• Pinocchio version: 3.2.0

[jcarpent]

Why do yo want to serialize casadi Models? The idea is to have only standard scalar to be serializable

[TexnoMann]

Why do yo want to serialize casadi Models? The idea is to have only standard scalar to be serializable

I'm using casadi Models as a backend to calculate filtered dynamics, and my wrapper model that I want to serialize includes cpin.Model. I can write high-level serialization with casadi Model exception if this is expected behavior and you don't plan to implement it.

[jcarpent]

The shortest way to do it would be to go through a pin.Model and to cast it to a casadi model using

cmodel = cpin.Model(model)