Function writeback_soft_bodies 

pub fn writeback_soft_bodies(
    rigid_body_sets: Query<'_, '_, &RapierRigidBodySet>,
    global_transforms: Query<'_, '_, &GlobalTransform>,
    soft_bodies: Query<'_, '_, (Entity, &RapierSoftBodyHandle, &RapierContextEntityLink, Option<&mut SoftBodyState>, Option<&mut Transform>, Option<&ChildOf>)>,
    clusters: Query<'_, '_, (&RapierRigidBodyHandle, &RapierContextEntityLink, &mut Transform, Option<&ChildOf>), (With<SoftBodyCluster>, Without<RapierSoftBodyHandle>)>,
)

System responsible for writing the state of the soft bodies and cluster proxies back into SoftBodyState and Transform components after a simulation step.