Differentiate between world and other robots

[kasra-eshaghi]

Hello,
The ranger models in stage_ros currently return the distance to nearby obstacles. However, they do not indicate if the obstacle being detected is part of the world (i.e. environment), or is another robot.

Ideally, I would like to be able to know whether the ranger is detecting another robot or the environment. Is there a way to do this?
I was considering using color information. For example, making all the robots yellow, and obstacles black, and combining sensor and color data to differentiate between robots and the environment. However, there is no color detection mechanism right now.

Any suggestions are much appreciated!