Define Particle Position without inertia

[promero]

I try to generate a save and load function for softbody object.
For that, I save on json file all particle positions.

When I load it, I define the position of each particle with velocity to zero.
I know that to keep positions I must define invMasses to zero.

If I do it works, because softbody particles are fixed.

My problem is that I don't want to fix the particles, particles must move depending ObiParticleAttachment.

What I need is to open the softbody on same position that I save before, and particles must be without movement, until I interact with ObiParticleAttachment elements.

In theory if velocity is zero, particles must keep positions but my softbody particles move a lot until loose inertial energy.

Any advice or help is appreciated.

Thanks