How to access the SkinnedMeshRenderer behind ObiSoftbodySkinner?

[josemendez]

But the blendshape works on skinned mesh.

Nope, that's not how blend shapes work at all. They work on the base mesh, prior to any skinning or skeletal deformation.

Imagine you make a blend shape for a facial expression. If you were to apply blend shapes on the skinned mesh (after skeletal animation), rotating the neck to the left then applying the blend shape would make the face morph into the original position facial expression, looking forward: it would "override" animation.

Same happens with softbody deformation. If you were to apply blend shapes after softbody simulation, the mesh would completely ignore the deformation due to the softbody and morph into the original, rigid blend shape. At this point you’d have blendshapes, but no softbody simulation.

So blend shapes must be applied *before* both skeletal animation and softbody simulation, which in the case of a softbody means recalculating the rest shape as modified by the blend shape.