[SOLVED] sofa+python

[lionel]

Hi,
I have some issues combining sofa and python.

I have a python script which adds new objects (named A1, A2,…) in my scene with a keyboard event.
A need to dynamically link a Data from these new objects (for instance, Vec3 positions) with an object already in the scene (named B).

I don’t know how to do it.
I tried to retrieve a vector of positions from B as a numpy array and add the new positions from Ai to it. But it did not work.

Has someone an idea ?

lionel

[max]

Hello Lionel,

The position vector is copied when accessed from python, so you need to copy it back for the changes to happen. When using numpy arrays, you also need to convert it to a python list first using .tolist(). Here is a short example:


import numpy as np

def createScene(node):

# create some dofs
dofs = node.createObject('MechanicalObject', template = 'Vec3')

# positions are copied
pos = dofs.position

# modification
pos[0][0] = 1

# debug
print 'before:', dofs.position

# commit changes
dofs.position = pos

# debug
print 'after:', dofs.position

# numpy array
pos = np.zeros( (10, 3) )
dofs.position = pos.tolist()

print 'numpy:', dofs.position


Hope this helps.

Best,

max.

edit: we really need a preview system for posts + unescaped code characters

[Hugo]

Thank you for your reply Max.
This helped (I confirmed it !)

Cheers,

Hugo

[Author]

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