I am developing a gpu rope plugin, but I need simulation result to change my character's motion trail.But I know that get data from gpu is too slow ,what can i do to solve this situation?

About this,I have two ideas.
First, Whether there is a methon which can send data from gpu to cpu asynchronously? I search this in internet,but get nothing.
Second,I do something to my character mesh directly in gpu,but how can I do this? Vertex shader? Vertex factory? Mesh shader?