Visible radius around object

Hello everyone. I am trying to make some kind of visible radius that is mobile (app) friendly. The radius is suppose to show on the ground around the object that is focused.

But my problem is that i dont realy know what i should use to make the line around the object. Because there is many ways to do it i presume. One way that came to my mind was to just have a radius model scale to the right size around the object. But i am here to ask for some tips on what i should use to make this radius effect

For reference on what i am trying to achive look at this picture from “Skulls of the Shogun” http://www.blogcdn.com/www.joystiq.com/media/2012/12/skullsurface014_530x298.jpg
It is the white line around the world that i am trying to achieve but in a 3d world

So any links, code snippets or general tips are welcome :slight_smile:

I am pretty sure WoW game uses 1-poligon plane, with a texture of selection.

You might want to take into consideration the normal of surface under the feat of your character, one way to check for it is through Physics.Raycast

However ray cast might be quite heavy for the game, I am not totally sure.