How change the default blue rectangle with white circle when detecting a plane?

In the UnityArkitPlugin example-I was working on the UnityARHittestExample scene.When we build it into a ios device which detects the horizontal and vertical planes.I do not want vertical planes so I turned them off.What I was looking for was to change the blue rectangle that appears when a horizontal plane is detected.I want to change into some white colour with a circular shape.I have seen in other apps where a polygon shape which grows according to the plane detection while scanning any horizontal surface.

How to achieve something like instead of a blue plane change it into some polygon which grows according to scanning the ground.?