GRID is a CAOS command used in Creatures 3 and Docking Station to allow the coder to examine things about the room next to the agent in four given directions.
GRID (integer) agent (agent) direction (integer)
Returns the ID of a room adjacent to the agent in the given direction. A straight line is drawn from the centre of the agent until it hits a room. Directions are LEFT, RGHT, _UP_, or DOWN. A value of -1 is returned if no room can be found.
From the grasshopper:
setv va60 prop grid ownr left 5 setv va61 prop grid ownr rght 5 doif va60 > va61 setv ov10 1 elif va60 < va61 setv ov10 -1 endi
This helps the grasshopper avoid bodies of water - it checks the level of CA 5 (bodies of water) to its left and right, then sets ov10 (the variable containing the direction the grasshopper moves) depending on which direction smells less like water.