Revision history [back]

I think, you are mixing two things. The PCL can be used to get the position of an object in your pointcloud. TF gives you an easy way to create trees of coordinate systems and compute relative positions between frames in your tree. Your problem could be solved by using the PCL to find the objects insert their positions as tf-frames into the tf-tree and then use the tf-functions to compute their velocities. (Although tf only supports positions, you'd have to compute the velocity yourself)