Question about the flow estimation coordinates in Waymo

[Robertwyq]

Thanks for your great work.

I notice that the flow estimation in Waymo is under the ego coordinates. pc1 and pc2 is under the ego coordinates, and adjust the gt flow by transformation.

Even though the evaluation is correct, the scene flow estimated by the model is a mixture of (scene motion-ego motion). Is there any problem in estimating the motion of a relatively static or completely static point?

Perhaps I have some misunderstandings, I am looking forward to your reply.