Pushing of model in Stage ROS

edit

I have found, similar question that was paste here 6 years ago, but there was no answer to it, so I decided to little refresh of that issue. I am using Stage package, and that package in theory provides option to move items with collisions. There is description that gripper_return parameter should be 1 to achieve it. However it does not work. The collision is treated as with unmovable object and there is a warning sign on robot that tries to push the box. Below is the code of that box to be pushed. I also paste link to the question that I found.

define box model
(
pose [0 0 0 0]
size [0.5 0.5 0.2]
origin [0 0 0 0]

color "green"
gripper_return 1
)

question link

Please help me, I need it to my diploma. And thanks for answers.