[ros-users] "object" extraction from a hokuyo 3D scan

Hi all,

I am using a Hokuyo laser range sensor scanning horizontally on a vertical
translating rail thus having 3D scan of the world. I would like to extract
some 3D volume of it (such as cubes). I am not used to play with such data
acquisition so I wonder if it already exist some marvellous ROS package
doing such scan extraction. In fact I am sure that PR2 are using it with a
rotation of the scanner, that's why I am asking here.

I may need to read some documentation to have the "keyword" of 3D
extraction, do not hesitate to give me some readings not to loose your time
in "noob" questions.

P.S.: a friend of mine is in copy because not on the list. I am sure he'll
be converted to the power of ROS after this :p