Getting coordinate position of different robots in a checkered box with objects around.

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Good day to you,

I am developing a simulation in Gazebo where the robot (one in the beginning) and then adding several robots later. The world I am using is a checkered box (8*8 in start, and then using other dimensions of the checkered boxes) too. I wish to know the coordinates of the boxes relative to the robot and the orientation (in degree/radians). I am finding it hard on how and where to start the whole process? Should I make a plugin or something else that is already there and I can use?

Thank you.