how to fix the Observation for obstacle landmark

[jslin053]

Hi, i created some landmarks as obstacles in my scenario like simple_tag.py, but i found that the
default observation function to entity_pos only record landmarks' center positions, without any info about its radius/size,
and thus in some case, when the agent, obstacle and goal_landmark are lined, the agent hesitates and cannot decide to bypass the obstacle from left or right,
and keep colliding with the obstacle,
is there something i misunderstand or how could i fix it ?

if there is somebody know how to deal with it, please help me, thanks for your reading and help!