It is a known fact that putting wards inside the neutral spawn camps prevents them from spawning but recently, I see our neutrals camps not spawning any creeps. I checked the replay and saw that the opposing team put the ward behind the neutral camp instead of the usual in-front.
This is new to me so now I ask how big is the radius(or area) that the game checks? I always thought is was a triangular area in front of the neutral camp.
EDIT: If the vision of the neutrals camps prevents them from spawning, then how come this ward does not prevent them from respawning?