pybullet soft body and rigid body collision

[Asiyeh]

Hi. i'm totally new to Bullet and i want to use it for my thesis. What i need is simulating collision between a soft body and rigid body which make soft body change its shape to rigid body's and save its new shape. I already searched into pybullet examples but cant find what i want.
i want to use this method for showing (and a little modeling) eye muscle (soft body) on human face (rigid body), i will glad to hear if somebody have another easier method.

[Asiyeh]

I've managed to load soft body with objId = p.loadSoftBody("objname.obj") but i cant get its position with p.getBasePositionAndOrientation(objId) do to "Failed" error and i cant set it with resetBasePositionAndOrientation ( no error at all just not working). However softbody cant move in example browser but it collides with rigid body and sometimes get through it ( I dont know why already, i guess its for number of vertex but i coudnt manage to show vertexes in browser to see what is happening)
* If there is documentation or tutorial on working with soft bodies it would be great to share. Thank you